13459 Commits

Author SHA1 Message Date
Dennis Zhou
f59653f6d3
percpu: use chunk scan_hint to skip some scanning
Just like blocks, chunks now maintain a scan_hint. This can be used to
skip some scanning by promoting the scan_hint to be the contig_hint.
The chunk's scan_hint is primarily updated on the backside and relies on
full scanning when a block becomes free or the free region spans across
blocks.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-08-25 14:31:16 +00:00
Dennis Zhou
e28f68efe5
percpu: convert chunk hints to be based on pcpu_block_md
As mentioned in the last patch, a chunk's hints are no different than a
block just responsible for more bits. This converts chunk level hints to
use a pcpu_block_md to maintain them. This lets us reuse the same hint
helper functions as a block. The left_free and right_free are unused by
the chunk's pcpu_block_md.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-08-25 14:31:16 +00:00
Dennis Zhou
9c466f2de6
percpu: make pcpu_block_md generic
In reality, a chunk is just a block covering a larger number of bits.
The hints themselves are one in the same. Rather than maintaining the
hints separately, first introduce nr_bits to genericize
pcpu_block_update() to correctly maintain block->right_free. The next
patch will convert chunk hints to be managed as a pcpu_block_md.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-08-25 14:31:16 +00:00
Dennis Zhou
793fac2a5f
percpu: use block scan_hint to only scan forward
Blocks now remember the latest scan_hint. This can be used on the
allocation path as when a contig_hint is broken, we can promote the
scan_hint to the contig_hint and scan forward from there. This works
because pcpu_block_refresh_hint() is only called on the allocation path
while block free regions are updated manually in
pcpu_block_update_hint_free().

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-08-25 14:31:15 +00:00
Dennis Zhou
f381bb8342
percpu: remember largest area skipped during allocation
Percpu allocations attempt to do first fit by scanning forward from the
first_free of a block. However, fragmentation from allocation requests
can cause holes not seen by block hint update functions. To address
this, create a local version of bitmap_find_next_zero_area_off() that
remembers the largest area skipped over. The caveat is that it only sees
regions skipped over due to not fitting, not regions skipped due to
alignment.

Prior to updating the scan_hint, a scan backwards is done to try and
recover free bits skipped due to alignment. While this can cause
scanning to miss earlier possible free areas, smaller allocations will
eventually fill those holes due to first fit.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-08-25 14:31:15 +00:00
Dennis Zhou
de6f43fc0c
percpu: add block level scan_hint
Fragmentation can cause both blocks and chunks to have an early
first_firee bit available, but only able to satisfy allocations much
later on. This patch introduces a scan_hint to help mitigate some
unnecessary scanning.

The scan_hint remembers the largest area prior to the contig_hint. If
the contig_hint == scan_hint, then scan_hint_start > contig_hint_start.
This is necessary for scan_hint discovery when refreshing a block.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-08-25 14:31:15 +00:00
Dennis Zhou
b77aeaecbc
percpu: set PCPU_BITMAP_BLOCK_SIZE to PAGE_SIZE
Previously, block size was flexible based on the constraint that the
GCD(PCPU_BITMAP_BLOCK_SIZE, PAGE_SIZE) > 1. However, this carried the
overhead that keeping a floating number of populated free pages required
scanning over the free regions of a chunk.

Setting the block size to be fixed at PAGE_SIZE lets us know when an
empty page becomes used as we will break a full contig_hint of a block.
This means we no longer have to scan the whole chunk upon breaking a
contig_hint which empty page management piggybacked off. A later patch
takes advantage of this to optimize the allocation path by only scanning
forward using the scan_hint introduced later too.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-08-25 14:31:15 +00:00
Dennis Zhou
0f08fa64d6
percpu: relegate chunks unusable when failing small allocations
In certain cases, requestors of percpu memory may want specific
alignments. However, it is possible to end up in situations where the
contig_hint matches, but the alignment does not. This causes excess
scanning of chunks that will fail. To prevent this, if a small
allocation fails (< 32B), the chunk is moved to the empty list. Once an
allocation is freed from that chunk, it is placed back into rotation.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-08-25 14:31:15 +00:00
Dennis Zhou
ac57e64155
percpu: manage chunks based on contig_bits instead of free_bytes
When a chunk becomes fragmented, it can end up having a large number of
small allocation areas free. The free_bytes sorting of chunks leads to
unnecessary checking of chunks that cannot satisfy the allocation.
Switch to contig_bits sorting to prevent scanning chunks that may not be
able to service the allocation request.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-08-25 14:31:15 +00:00
Dennis Zhou
c0ce971830
percpu: introduce helper to determine if two regions overlap
While block hints were always accurate, it's possible when spanning
across blocks that we miss updating the chunk's contig_hint. Rather than
rely on correctness of the boundaries of hints, do a full overlap
comparison.

A future patch introduces the scan_hint which makes the contig_hint
slightly fuzzy as they can at times be smaller than the actual hint.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-08-25 14:31:15 +00:00
Dennis Zhou
a2b7117deb
percpu: update free path with correct new free region
When updating the chunk's contig_hint on the free path of a hint that
does not touch the page boundaries, it was incorrectly using the
starting offset of the free region and the block's contig_hint. This
could lead to incorrect assumptions about fit given a size and better
alignment of the start. Fix this by using (end - start) as this is only
called when updating a hint within a block.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-08-25 14:31:14 +00:00
chenqiwu
9150993206
mm/page_alloc: simplify page_is_buddy() for better code readability
Simplify page_is_buddy() to reduce the redundant code for better code
readability.

Signed-off-by: chenqiwu <chenqiwu@xiaomi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Link: http://lkml.kernel.org/r/1583853751-5525-1-git-send-email-qiwuchen55@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-08-25 14:30:43 +00:00
Liu Xiang
fe53aea1d0
mm/vmalloc.c: remove unnecessary highmem_mask from parameter of gfpflags_allow_blocking()
gfpflags_allow_blocking() does not care about __GFP_HIGHMEM, so
highmem_mask can be removed.

Link: http://lkml.kernel.org/r/1568812319-3467-1-git-send-email-liuxiang_1999@126.com
Signed-off-by: Liu Xiang <liuxiang_1999@126.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-08-25 14:30:43 +00:00
Mel Gorman
9fdece4b65
mm, page_alloc: spread allocations across zones before introducing fragmentation
Patch series "Fragmentation avoidance improvements", v5.

It has been noted before that fragmentation avoidance (aka
anti-fragmentation) is not perfect. Given sufficient time or an adverse
workload, memory gets fragmented and the long-term success of high-order
allocations degrades. This series defines an adverse workload, a definition
of external fragmentation events (including serious) ones and a series
that reduces the level of those fragmentation events.

The details of the workload and the consequences are described in more
detail in the changelogs. However, from patch 1, this is a high-level
summary of the adverse workload. The exact details are found in the
mmtests implementation.

The broad details of the workload are as follows;

1. Create an XFS filesystem (not specified in the configuration but done
   as part of the testing for this patch)
2. Start 4 fio threads that write a number of 64K files inefficiently.
   Inefficiently means that files are created on first access and not
   created in advance (fio parameterr create_on_open=1) and fallocate
   is not used (fallocate=none). With multiple IO issuers this creates
   a mix of slab and page cache allocations over time. The total size
   of the files is 150% physical memory so that the slabs and page cache
   pages get mixed
3. Warm up a number of fio read-only threads accessing the same files
   created in step 2. This part runs for the same length of time it
   took to create the files. It'll fault back in old data and further
   interleave slab and page cache allocations. As it's now low on
   memory due to step 2, fragmentation occurs as pageblocks get
   stolen.
4. While step 3 is still running, start a process that tries to allocate
   75% of memory as huge pages with a number of threads. The number of
   threads is based on a (NR_CPUS_SOCKET - NR_FIO_THREADS)/4 to avoid THP
   threads contending with fio, any other threads or forcing cross-NUMA
   scheduling. Note that the test has not been used on a machine with less
   than 8 cores. The benchmark records whether huge pages were allocated
   and what the fault latency was in microseconds
5. Measure the number of events potentially causing external fragmentation,
   the fault latency and the huge page allocation success rate.
6. Cleanup

Overall the series reduces external fragmentation causing events by over 94%
on 1 and 2 socket machines, which in turn impacts high-order allocation
success rates over the long term. There are differences in latencies and
high-order allocation success rates. Latencies are a mixed bag as they
are vulnerable to exact system state and whether allocations succeeded
so they are treated as a secondary metric.

Patch 1 uses lower zones if they are populated and have free memory
	instead of fragmenting a higher zone. It's special cased to
	handle a Normal->DMA32 fallback with the reasons explained
	in the changelog.

Patch 2-4 boosts watermarks temporarily when an external fragmentation
	event occurs. kswapd wakes to reclaim a small amount of old memory
	and then wakes kcompactd on completion to recover the system
	slightly. This introduces some overhead in the slowpath. The level
	of boosting can be tuned or disabled depending on the tolerance
	for fragmentation vs allocation latency.

Patch 5 stalls some movable allocation requests to let kswapd from patch 4
	make some progress. The duration of the stalls is very low but it
	is possible to tune the system to avoid fragmentation events if
	larger stalls can be tolerated.

The bulk of the improvement in fragmentation avoidance is from patches
1-4 but patch 5 can deal with a rare corner case and provides the option
of tuning a system for THP allocation success rates in exchange for
some stalls to control fragmentation.

This patch (of 5):

The page allocator zone lists are iterated based on the watermarks of each
zone which does not take anti-fragmentation into account.  On x86, node 0
may have multiple zones while other nodes have one zone.  A consequence is
that tasks running on node 0 may fragment ZONE_NORMAL even though
ZONE_DMA32 has plenty of free memory.  This patch special cases the
allocator fast path such that it'll try an allocation from a lower local
zone before fragmenting a higher zone.  In this case, stealing of
pageblocks or orders larger than a pageblock are still allowed in the fast
path as they are uninteresting from a fragmentation point of view.

This was evaluated using a benchmark designed to fragment memory before
attempting THP allocations.  It's implemented in mmtests as the following
configurations

configs/config-global-dhp__workload_thpfioscale
configs/config-global-dhp__workload_thpfioscale-defrag
configs/config-global-dhp__workload_thpfioscale-madvhugepage

e.g. from mmtests
./run-mmtests.sh --run-monitor --config configs/config-global-dhp__workload_thpfioscale test-run-1

The broad details of the workload are as follows;

1. Create an XFS filesystem (not specified in the configuration but done
   as part of the testing for this patch).
2. Start 4 fio threads that write a number of 64K files inefficiently.
   Inefficiently means that files are created on first access and not
   created in advance (fio parameter create_on_open=1) and fallocate
   is not used (fallocate=none). With multiple IO issuers this creates
   a mix of slab and page cache allocations over time. The total size
   of the files is 150% physical memory so that the slabs and page cache
   pages get mixed.
3. Warm up a number of fio read-only processes accessing the same files
   created in step 2. This part runs for the same length of time it
   took to create the files. It'll refault old data and further
   interleave slab and page cache allocations. As it's now low on
   memory due to step 2, fragmentation occurs as pageblocks get
   stolen.
4. While step 3 is still running, start a process that tries to allocate
   75% of memory as huge pages with a number of threads. The number of
   threads is based on a (NR_CPUS_SOCKET - NR_FIO_THREADS)/4 to avoid THP
   threads contending with fio, any other threads or forcing cross-NUMA
   scheduling. Note that the test has not been used on a machine with less
   than 8 cores. The benchmark records whether huge pages were allocated
   and what the fault latency was in microseconds.
5. Measure the number of events potentially causing external fragmentation,
   the fault latency and the huge page allocation success rate.
6. Cleanup the test files.

Note that due to the use of IO and page cache that this benchmark is not
suitable for running on large machines where the time to fragment memory
may be excessive.  Also note that while this is one mix that generates
fragmentation that it's not the only mix that generates fragmentation.
Differences in workload that are more slab-intensive or whether SLUB is
used with high-order pages may yield different results.

When the page allocator fragments memory, it records the event using the
mm_page_alloc_extfrag ftrace event.  If the fallback_order is smaller than
a pageblock order (order-9 on 64-bit x86) then it's considered to be an
"external fragmentation event" that may cause issues in the future.
Hence, the primary metric here is the number of external fragmentation
events that occur with order < 9.  The secondary metric is allocation
latency and huge page allocation success rates but note that differences
in latencies and what the success rate also can affect the number of
external fragmentation event which is why it's a secondary metric.

1-socket Skylake machine
config-global-dhp__workload_thpfioscale XFS (no special madvise)
4 fio threads, 1 THP allocating thread
--------------------------------------

4.20-rc3 extfrag events < order 9:   804694
4.20-rc3+patch:                      408912 (49% reduction)

thpfioscale Fault Latencies
                                   4.20.0-rc3             4.20.0-rc3
                                      vanilla           lowzone-v5r8
Amean     fault-base-1      662.92 (   0.00%)      653.58 *   1.41%*
Amean     fault-huge-1        0.00 (   0.00%)        0.00 (   0.00%)

                              4.20.0-rc3             4.20.0-rc3
                                 vanilla           lowzone-v5r8
Percentage huge-1        0.00 (   0.00%)        0.00 (   0.00%)

Fault latencies are slightly reduced while allocation success rates remain
at zero as this configuration does not make any special effort to allocate
THP and fio is heavily active at the time and either filling memory or
keeping pages resident.  However, a 49% reduction of serious fragmentation
events reduces the changes of external fragmentation being a problem in
the future.

Vlastimil asked during review for a breakdown of the allocation types
that are falling back.

vanilla
   3816 MIGRATE_UNMOVABLE
 800845 MIGRATE_MOVABLE
     33 MIGRATE_UNRECLAIMABLE

patch
    735 MIGRATE_UNMOVABLE
 408135 MIGRATE_MOVABLE
     42 MIGRATE_UNRECLAIMABLE

The majority of the fallbacks are due to movable allocations and this is
consistent for the workload throughout the series so will not be presented
again as the primary source of fallbacks are movable allocations.

Movable fallbacks are sometimes considered "ok" to fallback because they
can be migrated.  The problem is that they can fill an
unmovable/reclaimable pageblock causing those allocations to fallback
later and polluting pageblocks with pages that cannot move.  If there is a
movable fallback, it is pretty much guaranteed to affect an
unmovable/reclaimable pageblock and while it might not be enough to
actually cause a unmovable/reclaimable fallback in the future, we cannot
know that in advance so the patch takes the only option available to it.
Hence, it's important to control them.  This point is also consistent
throughout the series and will not be repeated.

1-socket Skylake machine
global-dhp__workload_thpfioscale-madvhugepage-xfs (MADV_HUGEPAGE)
-----------------------------------------------------------------

4.20-rc3 extfrag events < order 9:  291392
4.20-rc3+patch:                     191187 (34% reduction)

thpfioscale Fault Latencies
                                   4.20.0-rc3             4.20.0-rc3
                                      vanilla           lowzone-v5r8
Amean     fault-base-1     1495.14 (   0.00%)     1467.55 (   1.85%)
Amean     fault-huge-1     1098.48 (   0.00%)     1127.11 (  -2.61%)

thpfioscale Percentage Faults Huge
                              4.20.0-rc3             4.20.0-rc3
                                 vanilla           lowzone-v5r8
Percentage huge-1       78.57 (   0.00%)       77.64 (  -1.18%)

Fragmentation events were reduced quite a bit although this is known
to be a little variable. The latencies and allocation success rates
are similar but they were already quite high.

2-socket Haswell machine
config-global-dhp__workload_thpfioscale XFS (no special madvise)
4 fio threads, 5 THP allocating threads
----------------------------------------------------------------

4.20-rc3 extfrag events < order 9:  215698
4.20-rc3+patch:                     200210 (7% reduction)

thpfioscale Fault Latencies
                                   4.20.0-rc3             4.20.0-rc3
                                      vanilla           lowzone-v5r8
Amean     fault-base-5     1350.05 (   0.00%)     1346.45 (   0.27%)
Amean     fault-huge-5     4181.01 (   0.00%)     3418.60 (  18.24%)

                              4.20.0-rc3             4.20.0-rc3
                                 vanilla           lowzone-v5r8
Percentage huge-5        1.15 (   0.00%)        0.78 ( -31.88%)

The reduction of external fragmentation events is slight and this is
partially due to the removal of __GFP_THISNODE in commit ac5b2c18911f
("mm: thp: relax __GFP_THISNODE for MADV_HUGEPAGE mappings") as THP
allocations can now spill over to remote nodes instead of fragmenting
local memory.

2-socket Haswell machine
global-dhp__workload_thpfioscale-madvhugepage-xfs (MADV_HUGEPAGE)
-----------------------------------------------------------------

4.20-rc3 extfrag events < order 9: 166352
4.20-rc3+patch:                    147463 (11% reduction)

thpfioscale Fault Latencies
                                   4.20.0-rc3             4.20.0-rc3
                                      vanilla           lowzone-v5r8
Amean     fault-base-5     6138.97 (   0.00%)     6217.43 (  -1.28%)
Amean     fault-huge-5     2294.28 (   0.00%)     3163.33 * -37.88%*

thpfioscale Percentage Faults Huge
                              4.20.0-rc3             4.20.0-rc3
                                 vanilla           lowzone-v5r8
Percentage huge-5       96.82 (   0.00%)       95.14 (  -1.74%)

There was a slight reduction in external fragmentation events although the
latencies were higher.  The allocation success rate is high enough that
the system is struggling and there is quite a lot of parallel reclaim and
compaction activity.  There is also a certain degree of luck on whether
processes start on node 0 or not for this patch but the relevance is
reduced later in the series.

Overall, the patch reduces the number of external fragmentation causing
events so the success of THP over long periods of time would be improved
for this adverse workload.

Link: http://lkml.kernel.org/r/20181123114528.28802-2-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[RealJohnGalt]: adapt for 4.14

Signed-off-by: azrim <mirzaspc@gmail.com>
2022-08-25 14:30:41 +00:00
Minchan Kim
c9f283e9d0
ANDROID: mm: use alloc_flags for cma first alloc policy
rmqueue internal functions to allocate cma memory should use
alloc_flags instead of gfp_flags because it's more restricted flags
to be considered allocation context. Otherwise, we could allocate
page from CMA area even though current context already disable
cma memory allocation. For example, current allocation context is
limited not to allocate the page from CMA area by PF_MEMALLOC_NOCMA
to prevent longterm pin but it's ignored so the longterm pin page
could be allocated from CMA area.

Bug: 178019362
Signed-off-by: Minchan Kim <minchan@google.com>
Change-Id: I61bd4642c91ecd9153f6c59f89e296e8b515f1ad
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-08-25 14:27:46 +00:00
Waiman Long
3f83025b10
mm/vmalloc: Fix unlock order in s_stop()
When multiple locks are acquired, they should be released in reverse
order. For s_start() and s_stop() in mm/vmalloc.c, that is not the
case.

  s_start: mutex_lock(&vmap_purge_lock); spin_lock(&vmap_area_lock);
  s_stop : mutex_unlock(&vmap_purge_lock); spin_unlock(&vmap_area_lock);

This unlock sequence, though allowed, is not optimal. If a waiter is
present, mutex_unlock() will need to go through the slowpath of waking
up the waiter with preemption disabled. Fix that by releasing the
spinlock first before the mutex.

Link: https://lkml.kernel.org/r/20201213180843.16938-1-longman@redhat.com
Fixes: e36176be1c39 ("mm/vmalloc: rework vmap_area_lock")
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-08-25 14:27:45 +00:00
Miaohe Lin
06a6d6c51e mm/mmap.c: fix missing call to vm_unacct_memory in mmap_region
[ Upstream commit 7f82f922319ede486540e8746769865b9508d2c2 ]

Since the beginning, charged is set to 0 to avoid calling vm_unacct_memory
twice because vm_unacct_memory will be called by above unmap_region.  But
since commit 4f74d2c8e827 ("vm: remove 'nr_accounted' calculations from
the unmap_vmas() interfaces"), unmap_region doesn't call vm_unacct_memory
anymore.  So charged shouldn't be set to 0 now otherwise the calling to
paired vm_unacct_memory will be missed and leads to imbalanced account.

Link: https://lkml.kernel.org/r/20220618082027.43391-1-linmiaohe@huawei.com
Fixes: 4f74d2c8e827 ("vm: remove 'nr_accounted' calculations from the unmap_vmas() interfaces")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-25 11:11:23 +02:00
Chris Goldsworthy
fd55aed621
ANDROID: mm: cma: retry allocations in cma_alloc
CMA allocations will fail if 'pinned' pages are in a CMA area, since
we cannot migrate pinned pages. The _refcount of a struct page being
greater than _mapcount for that page can cause pinning for anonymous
pages.  This is because try_to_unmap(), which (1) is called in the CMA
allocation path, and (2) decrements both _refcount and _mapcount for a
page, will stop unmapping a page from VMAs once the _mapcount for a
page reaches 0.  This implies that after try_to_unmap() has finished
successfully for a page where _recount > _mapcount, that _refcount
will be greater than 0.  Later in the CMA allocation path in
migrate_page_move_mapping(), we will have one more reference count
than intended for anonymous pages, meaning the allocation will fail
for that page.

One example of where _refcount can be greater than _mapcount for a
page we would not expect to be pinned is inside of copy_one_pte(),
which is called during a fork. For ptes for which pte_present(pte) ==
true, copy_one_pte() will increment the _refcount field followed by
the  _mapcount field of a page. If the process doing copy_one_pte() is
context switched out after incrementing _refcount but before
incrementing _mapcount, then the page will be temporarily pinned.

So, inside of cma_alloc(), instead of giving up when
alloc_contig_range() returns -EBUSY after having scanned a whole
CMA-region bitmap, perform retries with sleeps to give the system an
opportunity to unpin any pinned pages.

Additionally, based off feedback by Minchan Kim, add the ability to
exit early if a fatal signal is pending (this is a delta from the
mailing-list version of this patch).

Bug: 168521646
Link: https://lore.kernel.org/lkml/1596682582-29139-2-git-send-email-cgoldswo@codeaurora.org/
Signed-off-by: Chris Goldsworthy <cgoldswo@codeaurora.org>
Co-developed-by: Susheel Khiani <skhiani@codeaurora.org>
Signed-off-by: Susheel Khiani <skhiani@codeaurora.org>
Co-developed-by: Vinayak Menon <vinmenon@codeaurora.org>
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
Change-Id: I2f0c8388f9163e0decd631d9ae07bb6ad9ab79c8
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-08-03 08:47:51 +00:00
Kazuki Hashimoto
c5ae090ed2
Revert "mm: cma: sleep between retries in cma_alloc"
This reverts commit 8ffd0015dd9e44b597acd5c436d8de14de9de648.

Signed-off-by: Kazuki Hashimoto <kazukih@tuta.io>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-08-03 08:47:51 +00:00
Kazuki Hashimoto
1639de41dc
Revert "mm: cma: Increase retries if less blocks available"
This reverts commit 5a883fb75e3aa713c4e59ca78ab9acd09b78890e.

Signed-off-by: Kazuki Hashimoto <kazukih@tuta.io>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-08-03 08:47:51 +00:00
Kazuki Hashimoto
b885283394
Revert "mm: cma: retry only on EBUSY"
This reverts commit 54261b6432159003546e392c1f2a3fa94ed43240.

Signed-off-by: Kazuki Hashimoto <kazukih@tuta.io>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-08-03 08:47:51 +00:00
Minchan Kim
b58f06a371
ANDROID: mm: do not try test_page_isoalte if migration fails
Currently, alloc_contig_range expects that even though a page fails
with -EBUSY from __alloc_contig_migrate_range, it want to check
those failed pages in test_pages_isolated again with hope that
those page would be freed soon so cma allocatoin would be succeeded.
However, it depends on the luck and I found sometimes test_page_isolated
constantly fails at the page repeatedly whenever cma_alloc retried.
Rather than burning out CPU to check the page's status in
test_pages_isolated for GFP_NORETRY allocation, just bail out and
relies on the user what they want to do.
Currently, this option works for only __GFP_NORETRY case for safe
of existing other users.

Bug: 192475091
Signed-off-by: Minchan Kim <minchan@google.com>
Change-Id: I9211452be06960dc7d8f854537e53b3fc5262c8e
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-08-03 08:47:51 +00:00
Minchan Kim
b87443c8c0
FROMGIT: mm: remove lru_add_drain_all in alloc_contig_range
__alloc_contig_migrate_range already has lru_add_drain_all call via
migrate_prep.  It's necessary to move LRU taget pages into LRU list to be
able to isolated.  However, lru_add_drain_all call after
__alloc_contig_migrate_range is pointless since it has changed source page
freeing from putback_lru_pages to put_page[1].

This patch removes it.

[1] c6c919eb90e0, ("mm: use put_page() to free page instead of putback_lru_page()"

Link: https://lkml.kernel.org/r/20210303204512.2863087-1-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Minchan Kim <minchan@google.com>
Bug: 181887812
(cherry picked from https://lore.kernel.org/mm-commits/20210303230112.sxLQLXDXF%25akpm@linux-foundation.org/)
Change-Id: I53b6a7a0499d6580fb6febb7ae6ec12c3f871224
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-08-03 08:47:51 +00:00
azrim
6ac613581b
Merge remote-tracking branch 'google/android-4.14-stable' into richelieu
* google/android-4.14-stable:
  FROMLIST: binder: fix UAF of ref->proc caused by race condition
  UPSTREAM: x86/pci: Fix the function type for check_reserved_t
  Linux 4.14.290
  PCI: hv: Fix interrupt mapping for multi-MSI
  PCI: hv: Reuse existing IRTE allocation in compose_msi_msg()
  PCI: hv: Fix hv_arch_irq_unmask() for multi-MSI
  PCI: hv: Fix multi-MSI to allow more than one MSI vector
  net: usb: ax88179_178a needs FLAG_SEND_ZLP
  tty: use new tty_insert_flip_string_and_push_buffer() in pty_write()
  tty: extract tty_flip_buffer_commit() from tty_flip_buffer_push()
  tty: drop tty_schedule_flip()
  tty: the rest, stop using tty_schedule_flip()
  tty: drivers/tty/, stop using tty_schedule_flip()
  Bluetooth: Fix bt_skb_sendmmsg not allocating partial chunks
  Bluetooth: SCO: Fix sco_send_frame returning skb->len
  Bluetooth: Fix passing NULL to PTR_ERR
  Bluetooth: RFCOMM: Replace use of memcpy_from_msg with bt_skb_sendmmsg
  Bluetooth: SCO: Replace use of memcpy_from_msg with bt_skb_sendmsg
  Bluetooth: Add bt_skb_sendmmsg helper
  Bluetooth: Add bt_skb_sendmsg helper
  ALSA: memalloc: Align buffer allocations in page size
  tilcdc: tilcdc_external: fix an incorrect NULL check on list iterator
  drm/tilcdc: Remove obsolete crtc_mode_valid() hack
  bpf: Make sure mac_header was set before using it
  mm/mempolicy: fix uninit-value in mpol_rebind_policy()
  Revert "Revert "char/random: silence a lockdep splat with printk()""
  be2net: Fix buffer overflow in be_get_module_eeprom
  tcp: Fix a data-race around sysctl_tcp_notsent_lowat.
  igmp: Fix a data-race around sysctl_igmp_max_memberships.
  igmp: Fix data-races around sysctl_igmp_llm_reports.
  net: stmmac: fix dma queue left shift overflow issue
  i2c: cadence: Change large transfer count reset logic to be unconditional
  tcp: Fix a data-race around sysctl_tcp_probe_interval.
  tcp: Fix a data-race around sysctl_tcp_probe_threshold.
  tcp/dccp: Fix a data-race around sysctl_tcp_fwmark_accept.
  ip: Fix a data-race around sysctl_fwmark_reflect.
  perf/core: Fix data race between perf_event_set_output() and perf_mmap_close()
  power/reset: arm-versatile: Fix refcount leak in versatile_reboot_probe
  xfrm: xfrm_policy: fix a possible double xfrm_pols_put() in xfrm_bundle_lookup()
  xen/gntdev: Ignore failure to unmap INVALID_GRANT_HANDLE
2022-08-03 08:32:56 +00:00
John Galt
3a03bd4b85
mm/swap.c: complete 5a9bd6bb520
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 10:08:34 +00:00
Aaron Lu
fbbd87b7f6
mm, page_alloc: double zone's batchsize
To improve page allocator's performance for order-0 pages, each CPU has
a Per-CPU-Pageset(PCP) per zone.  Whenever an order-0 page is needed,
PCP will be checked first before asking pages from Buddy.  When PCP is
used up, a batch of pages will be fetched from Buddy to improve
performance and the size of batch can affect performance.

zone's batch size gets doubled last time by commit ba56e91c9401("mm:
page_alloc: increase size of per-cpu-pages") over ten years ago.  Since
then, CPU has envolved a lot and CPU's cache sizes also increased.

Dave Hansen is concerned the current batch size doesn't fit well with
modern hardware and suggested me to do two things: first, use a page
allocator intensive benchmark, e.g.  will-it-scale/page_fault1 to find
out how performance changes with different batch sizes on various
machines and then choose a new default batch size; second, see how this
new batch size work with other workloads.

In the first test, we saw performance gains on high-core-count systems
and little to no effect on older systems with more modest core counts.
In this phase's test data, two candidates: 63 and 127 are chosen.

In the second step, ebizzy, oltp, kbuild, pigz, netperf, vm-scalability
and more will-it-scale sub-tests are tested to see how these two
candidates work with these workloads and decides a new default according
to their results.

Most test results are flat.  will-it-scale/page_fault2 process mode has
10%-18% performance increase on 4-sockets Skylake and Broadwell.
vm-scalability/lru-file-mmap-read has 17%-47% performance increase for
4-sockets servers while for 2-sockets servers, it caused 3%-8% performance
drop.  Further analysis showed that, with a larger pcp->batch and thus
larger pcp->high(the relationship of pcp->high=6 * pcp->batch is
maintained in this patch), zone lock contention shifted to LRU add side
lock contention and that caused performance drop.  This performance drop
might be mitigated by others' work on optimizing LRU lock.

Another downside of increasing pcp->batch is, when PCP is used up and need
to fetch a batch of pages from Buddy, since batch is increased, that time
can be longer than before.  My understanding is, this doesn't affect
slowpath where direct reclaim and compaction dominates.  For fastpath,
throughput is a win(according to will-it-scale/page_fault1) but worst
latency can be larger now.

Overall, I think double the batch size from 31 to 63 is relatively safe
and provide good performance boost for high-core-count systems.

The two phase's test results are listed below(all tests are done with THP
disabled).

Phase one(will-it-scale/page_fault1) test results:

Skylake-EX: increased batch size has a good effect on zone->lock
contention, though LRU contention will rise at the same time and
limited the final performance increase.

batch   score     change   zone_contention   lru_contention   total_contention
 31   15345900    +0.00%       64%                 8%           72%
 53   17903847   +16.67%       32%                38%           70%
 63   17992886   +17.25%       24%                45%           69%
 73   18022825   +17.44%       10%                61%           71%
119   18023401   +17.45%        4%                66%           70%
127   18029012   +17.48%        3%                66%           69%
137   18036075   +17.53%        4%                66%           70%
165   18035964   +17.53%        2%                67%           69%
188   18101105   +17.95%        2%                67%           69%
223   18130951   +18.15%        2%                67%           69%
255   18118898   +18.07%        2%                67%           69%
267   18101559   +17.96%        2%                67%           69%
299   18160468   +18.34%        2%                68%           70%
320   18139845   +18.21%        2%                67%           69%
393   18160869   +18.34%        2%                68%           70%
424   18170999   +18.41%        2%                68%           70%
458   18144868   +18.24%        2%                68%           70%
467   18142366   +18.22%        2%                68%           70%
498   18154549   +18.30%        1%                68%           69%
511   18134525   +18.17%        1%                69%           70%

Broadwell-EX: similar pattern as Skylake-EX.

batch   score     change   zone_contention   lru_contention   total_contention
 31   16703983    +0.00%       67%                 7%           74%
 53   18195393    +8.93%       43%                28%           71%
 63   18288885    +9.49%       38%                33%           71%
 73   18344329    +9.82%       35%                37%           72%
119   18535529   +10.96%       24%                46%           70%
127   18513596   +10.83%       23%                48%           71%
137   18514327   +10.84%       23%                48%           71%
165   18511840   +10.82%       22%                49%           71%
188   18593478   +11.31%       17%                53%           70%
223   18601667   +11.36%       17%                52%           69%
255   18774825   +12.40%       12%                58%           70%
267   18754781   +12.28%        9%                60%           69%
299   18892265   +13.10%        7%                63%           70%
320   18873812   +12.99%        8%                62%           70%
393   18891174   +13.09%        6%                64%           70%
424   18975108   +13.60%        6%                64%           70%
458   18932364   +13.34%        8%                62%           70%
467   18960891   +13.51%        5%                65%           70%
498   18944526   +13.41%        5%                64%           69%
511   18960839   +13.51%        5%                64%           69%

Skylake-EP: although increased batch reduced zone->lock contention, but
the effect is not as good as EX: zone->lock contention is still as high as
20% with a very high batch value instead of 1% on Skylake-EX or 5% on
Broadwell-EX.  Also, total_contention actually decreased with a higher
batch but that doesn't translate to performance increase.

batch   score    change   zone_contention   lru_contention   total_contention
 31   9554867    +0.00%       66%                 3%           69%
 53   9855486    +3.15%       63%                 3%           66%
 63   9980145    +4.45%       62%                 4%           66%
 73   10092774   +5.63%       62%                 5%           67%
119   10310061   +7.90%       45%                19%           64%
127   10342019   +8.24%       42%                19%           61%
137   10358182   +8.41%       42%                21%           63%
165   10397060   +8.81%       37%                24%           61%
188   10341808   +8.24%       34%                26%           60%
223   10349135   +8.31%       31%                27%           58%
255   10327189   +8.08%       28%                29%           57%
267   10344204   +8.26%       27%                29%           56%
299   10325043   +8.06%       25%                30%           55%
320   10310325   +7.91%       25%                31%           56%
393   10293274   +7.73%       21%                31%           52%
424   10311099   +7.91%       21%                32%           53%
458   10321375   +8.02%       21%                32%           53%
467   10303881   +7.84%       21%                32%           53%
498   10332462   +8.14%       20%                33%           53%
511   10325016   +8.06%       20%                32%           52%

Broadwell-EP: zone->lock and lru lock had an agreement to make sure
performance doesn't increase and they successfully managed to keep total
contention at 70%.

batch   score    change   zone_contention   lru_contention   total_contention
 31   10121178   +0.00%       19%                50%           69%
 53   10142366   +0.21%        6%                63%           69%
 63   10117984   -0.03%       11%                58%           69%
 73   10123330   +0.02%        7%                63%           70%
119   10108791   -0.12%        2%                67%           69%
127   10166074   +0.44%        3%                66%           69%
137   10141574   +0.20%        3%                66%           69%
165   10154499   +0.33%        2%                68%           70%
188   10124921   +0.04%        2%                67%           69%
223   10137399   +0.16%        2%                67%           69%
255   10143289   +0.22%        0%                68%           68%
267   10123535   +0.02%        1%                68%           69%
299   10140952   +0.20%        0%                68%           68%
320   10163170   +0.41%        0%                68%           68%
393   10000633   -1.19%        0%                69%           69%
424   10087998   -0.33%        0%                69%           69%
458   10187116   +0.65%        0%                69%           69%
467   10146790   +0.25%        0%                69%           69%
498   10197958   +0.76%        0%                69%           69%
511   10152326   +0.31%        0%                69%           69%

Haswell-EP: similar to Broadwell-EP.

batch   score   change   zone_contention   lru_contention   total_contention
 31   10442205   +0.00%       14%                48%           62%
 53   10442255   +0.00%        5%                57%           62%
 63   10452059   +0.09%        6%                57%           63%
 73   10482349   +0.38%        5%                59%           64%
119   10454644   +0.12%        3%                60%           63%
127   10431514   -0.10%        3%                59%           62%
137   10423785   -0.18%        3%                60%           63%
165   10481216   +0.37%        2%                61%           63%
188   10448755   +0.06%        2%                61%           63%
223   10467144   +0.24%        2%                61%           63%
255   10480215   +0.36%        2%                61%           63%
267   10484279   +0.40%        2%                61%           63%
299   10466450   +0.23%        2%                61%           63%
320   10452578   +0.10%        2%                61%           63%
393   10499678   +0.55%        1%                62%           63%
424   10481454   +0.38%        1%                62%           63%
458   10473562   +0.30%        1%                62%           63%
467   10484269   +0.40%        0%                62%           62%
498   10505599   +0.61%        0%                62%           62%
511   10483395   +0.39%        0%                62%           62%

Westmere-EP: contention is pretty small so not interesting.  Note too high
a batch value could hurt performance.

batch   score   change   zone_contention   lru_contention   total_contention
 31   4831523   +0.00%        2%                 3%            5%
 53   4834086   +0.05%        2%                 4%            6%
 63   4834262   +0.06%        2%                 3%            5%
 73   4832851   +0.03%        2%                 4%            6%
119   4830534   -0.02%        1%                 3%            4%
127   4827461   -0.08%        1%                 4%            5%
137   4827459   -0.08%        1%                 3%            4%
165   4820534   -0.23%        0%                 4%            4%
188   4817947   -0.28%        0%                 3%            3%
223   4809671   -0.45%        0%                 3%            3%
255   4802463   -0.60%        0%                 4%            4%
267   4801634   -0.62%        0%                 3%            3%
299   4798047   -0.69%        0%                 3%            3%
320   4793084   -0.80%        0%                 3%            3%
393   4785877   -0.94%        0%                 3%            3%
424   4782911   -1.01%        0%                 3%            3%
458   4779346   -1.08%        0%                 3%            3%
467   4780306   -1.06%        0%                 3%            3%
498   4780589   -1.05%        0%                 3%            3%
511   4773724   -1.20%        0%                 3%            3%

Skylake-Desktop: similar to Westmere-EP, nothing interesting.

batch   score   change   zone_contention   lru_contention   total_contention
 31   3906608   +0.00%        2%                 3%            5%
 53   3940164   +0.86%        2%                 3%            5%
 63   3937289   +0.79%        2%                 3%            5%
 73   3940201   +0.86%        2%                 3%            5%
119   3933240   +0.68%        2%                 3%            5%
127   3930514   +0.61%        2%                 4%            6%
137   3938639   +0.82%        0%                 3%            3%
165   3908755   +0.05%        0%                 3%            3%
188   3905621   -0.03%        0%                 3%            3%
223   3903015   -0.09%        0%                 4%            4%
255   3889480   -0.44%        0%                 3%            3%
267   3891669   -0.38%        0%                 4%            4%
299   3898728   -0.20%        0%                 4%            4%
320   3894547   -0.31%        0%                 4%            4%
393   3875137   -0.81%        0%                 4%            4%
424   3874521   -0.82%        0%                 3%            3%
458   3880432   -0.67%        0%                 4%            4%
467   3888715   -0.46%        0%                 3%            3%
498   3888633   -0.46%        0%                 4%            4%
511   3875305   -0.80%        0%                 5%            5%

Haswell-Desktop: zone->lock is pretty low as other desktops, though lru
contention is higher than other desktops.

batch   score   change   zone_contention   lru_contention   total_contention
 31   3511158   +0.00%        2%                 5%            7%
 53   3555445   +1.26%        2%                 6%            8%
 63   3561082   +1.42%        2%                 6%            8%
 73   3547218   +1.03%        2%                 6%            8%
119   3571319   +1.71%        1%                 7%            8%
127   3549375   +1.09%        0%                 6%            6%
137   3560233   +1.40%        0%                 6%            6%
165   3555176   +1.25%        2%                 6%            8%
188   3551501   +1.15%        0%                 8%            8%
223   3531462   +0.58%        0%                 7%            7%
255   3570400   +1.69%        0%                 7%            7%
267   3532235   +0.60%        1%                 8%            9%
299   3562326   +1.46%        0%                 6%            6%
320   3553569   +1.21%        0%                 8%            8%
393   3539519   +0.81%        0%                 7%            7%
424   3549271   +1.09%        0%                 8%            8%
458   3528885   +0.50%        0%                 8%            8%
467   3526554   +0.44%        0%                 7%            7%
498   3525302   +0.40%        0%                 9%            9%
511   3527556   +0.47%        0%                 8%            8%

Sandybridge-Desktop: the 0% contention isn't accurate but caused by
dropped fractional part. Since multiple contention path's contentions
are all under 1% here, with some arithmetic operations like add, the
final deviation could be as large as 3%.

batch   score   change   zone_contention   lru_contention   total_contention
 31   1744495   +0.00%        0%                 0%            0%
 53   1755341   +0.62%        0%                 0%            0%
 63   1758469   +0.80%        0%                 0%            0%
 73   1759626   +0.87%        0%                 0%            0%
119   1770417   +1.49%        0%                 0%            0%
127   1768252   +1.36%        0%                 0%            0%
137   1767848   +1.34%        0%                 0%            0%
165   1765088   +1.18%        0%                 0%            0%
188   1766918   +1.29%        0%                 0%            0%
223   1767866   +1.34%        0%                 0%            0%
255   1768074   +1.35%        0%                 0%            0%
267   1763187   +1.07%        0%                 0%            0%
299   1765620   +1.21%        0%                 0%            0%
320   1767603   +1.32%        0%                 0%            0%
393   1764612   +1.15%        0%                 0%            0%
424   1758476   +0.80%        0%                 0%            0%
458   1758593   +0.81%        0%                 0%            0%
467   1757915   +0.77%        0%                 0%            0%
498   1753363   +0.51%        0%                 0%            0%
511   1755548   +0.63%        0%                 0%            0%

Phase two test results:
Note: all percent change is against base(batch=31).

ebizzy.throughput (higer is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1    2410037±7%     2600451±2% +7.9%     2602878 +8.0%
lkp-bdw-ex1     1493328        1489243    -0.3%     1492145 -0.1%
lkp-skl-2sp2    1329674        1345891    +1.2%     1351056 +1.6%
lkp-bdw-ep2      711511         711511     0.0%      710708 -0.1%
lkp-wsm-ep2       75750          75528    -0.3%       75441 -0.4%
lkp-skl-d01      264126         262791    -0.5%      264113 +0.0%
lkp-hsw-d01      176601         176328    -0.2%      176368 -0.1%
lkp-sb02          98937          98937    +0.0%       99030 +0.1%

kbuild.buildtime (less is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1     107.00        107.67  +0.6%        107.11  +0.1%
lkp-bdw-ex1       97.33         97.33  +0.0%         97.42  +0.1%
lkp-skl-2sp2     180.00        179.83  -0.1%        179.83  -0.1%
lkp-bdw-ep2      178.17        179.17  +0.6%        177.50  -0.4%
lkp-wsm-ep2      737.00        738.00  +0.1%        738.00  +0.1%
lkp-skl-d01      642.00        653.00  +1.7%        653.00  +1.7%
lkp-hsw-d01     1310.00       1316.00  +0.5%       1311.00  +0.1%

netperf/TCP_STREAM.Throughput_total_Mbps (higher is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1     948790        947144  -0.2%        948333 -0.0%
lkp-bdw-ex1      904224        904366  +0.0%        904926 +0.1%
lkp-skl-2sp2     239731        239607  -0.1%        239565 -0.1%
lk-bdw-ep2       365764        365933  +0.0%        365951 +0.1%
lkp-wsm-ep2       93736         93803  +0.1%         93808 +0.1%
lkp-skl-d01       77314         77303  -0.0%         77375 +0.1%
lkp-hsw-d01       58617         60387  +3.0%         60208 +2.7%
lkp-sb02          29990         30137  +0.5%         30103 +0.4%

oltp.transactions (higer is better)

machine         batch=31      batch=63             batch=127
lkp-bdw-ex1      9073276       9100377     +0.3%    9036344     -0.4%
lkp-skl-2sp2     8898717       8852054     -0.5%    8894459     -0.0%
lkp-bdw-ep2     13426155      13384654     -0.3%   13333637     -0.7%
lkp-hsw-ep2     13146314      13232784     +0.7%   13193163     +0.4%
lkp-wsm-ep2      5035355       5019348     -0.3%    5033418     -0.0%
lkp-skl-d01       418485       4413339     -0.1%    4419039     +0.0%
lkp-hsw-d01      3517817±5%    3396120±3%  -3.5%    3455138±3%  -1.8%

pigz.throughput (higer is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1    1.513e+08     1.507e+08 -0.4%      1.511e+08 -0.2%
lkp-bdw-ex1     2.060e+08     2.052e+08 -0.4%      2.044e+08 -0.8%
lkp-skl-2sp2    8.836e+08     8.845e+08 +0.1%      8.836e+08 -0.0%
lkp-bdw-ep2     8.275e+08     8.464e+08 +2.3%      8.330e+08 +0.7%
lkp-wsm-ep2     2.224e+08     2.221e+08 -0.2%      2.218e+08 -0.3%
lkp-skl-d01     1.177e+08     1.177e+08 -0.0%      1.176e+08 -0.1%
lkp-hsw-d01     1.154e+08     1.154e+08 +0.1%      1.154e+08 -0.0%
lkp-sb02        0.633e+08     0.633e+08 +0.1%      0.633e+08 +0.0%

will-it-scale.malloc1.processes (higher is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1      620181       620484 +0.0%         620240 +0.0%
lkp-bdw-ex1      1403610      1401201 -0.2%        1417900 +1.0%
lkp-skl-2sp2     1288097      1284145 -0.3%        1283907 -0.3%
lkp-bdw-ep2      1427879      1427675 -0.0%        1428266 +0.0%
lkp-hsw-ep2      1362546      1353965 -0.6%        1354759 -0.6%
lkp-wsm-ep2      2099657      2107576 +0.4%        2100226 +0.0%
lkp-skl-d01      1476835      1476358 -0.0%        1474487 -0.2%
lkp-hsw-d01      1308810      1303429 -0.4%        1301299 -0.6%
lkp-sb02          589286       589284 -0.0%         588101 -0.2%

will-it-scale.malloc1.threads (higher is better)
machine         batch=31      batch=63             batch=127
lkp-skl-4sp1     21289         21125     -0.8%      21241     -0.2%
lkp-bdw-ex1      28114         28089     -0.1%      28007     -0.4%
lkp-skl-2sp2     91866         91946     +0.1%      92723     +0.9%
lkp-bdw-ep2      37637         37501     -0.4%      37317     -0.9%
lkp-hsw-ep2      43673         43590     -0.2%      43754     +0.2%
lkp-wsm-ep2      28577         28298     -1.0%      28545     -0.1%
lkp-skl-d01     175277        173343     -1.1%     173082     -1.3%
lkp-hsw-d01     130303        129566     -0.6%     129250     -0.8%
lkp-sb02        113742±3%     116911     +2.8%     116417±3%  +2.4%

will-it-scale.malloc2.processes (higer is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1    1.206e+09     1.206e+09 -0.0%      1.206e+09 +0.0%
lkp-bdw-ex1     1.319e+09     1.319e+09 -0.0%      1.319e+09 +0.0%
lkp-skl-2sp2    8.000e+08     8.021e+08 +0.3%      7.995e+08 -0.1%
lkp-bdw-ep2     6.582e+08     6.634e+08 +0.8%      6.513e+08 -1.1%
lkp-hsw-ep2     6.671e+08     6.669e+08 -0.0%      6.665e+08 -0.1%
lkp-wsm-ep2     1.805e+08     1.806e+08 +0.0%      1.804e+08 -0.1%
lkp-skl-d01     1.611e+08     1.611e+08 -0.0%      1.610e+08 -0.0%
lkp-hsw-d01     1.333e+08     1.332e+08 -0.0%      1.332e+08 -0.0%
lkp-sb02         82485104      82478206 -0.0%       82473546 -0.0%

will-it-scale.malloc2.threads (higer is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1    1.574e+09     1.574e+09 -0.0%      1.574e+09 -0.0%
lkp-bdw-ex1     1.737e+09     1.737e+09 +0.0%      1.737e+09 -0.0%
lkp-skl-2sp2    9.161e+08     9.162e+08 +0.0%      9.181e+08 +0.2%
lkp-bdw-ep2     7.856e+08     8.015e+08 +2.0%      8.113e+08 +3.3%
lkp-hsw-ep2     6.908e+08     6.904e+08 -0.1%      6.907e+08 -0.0%
lkp-wsm-ep2     2.409e+08     2.409e+08 +0.0%      2.409e+08 -0.0%
lkp-skl-d01     1.199e+08     1.199e+08 -0.0%      1.199e+08 -0.0%
lkp-hsw-d01     1.029e+08     1.029e+08 -0.0%      1.029e+08 +0.0%
lkp-sb02         68081213      68061423 -0.0%       68076037 -0.0%

will-it-scale.page_fault2.processes (higer is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1    14509125±4%   16472364 +13.5%       17123117 +18.0%
lkp-bdw-ex1     14736381      16196588  +9.9%       16364011 +11.0%
lkp-skl-2sp2     6354925       6435444  +1.3%        6436644  +1.3%
lkp-bdw-ep2      8749584       8834422  +1.0%        8827179  +0.9%
lkp-hsw-ep2      8762591       8845920  +1.0%        8825697  +0.7%
lkp-wsm-ep2      3036083       3030428  -0.2%        3021741  -0.5%
lkp-skl-d01      2307834       2304731  -0.1%        2286142  -0.9%
lkp-hsw-d01      1806237       1800786  -0.3%        1795943  -0.6%
lkp-sb02          842616        837844  -0.6%         833921  -1.0%

will-it-scale.page_fault2.threads

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1     1623294       1615132±2% -0.5%     1656777    +2.1%
lkp-bdw-ex1      1995714       2025948    +1.5%     2113753±3% +5.9%
lkp-skl-2sp2     2346708       2415591    +2.9%     2416919    +3.0%
lkp-bdw-ep2      2342564       2344882    +0.1%     2300206    -1.8%
lkp-hsw-ep2      1820658       1831681    +0.6%     1844057    +1.3%
lkp-wsm-ep2      1725482       1733774    +0.5%     1740517    +0.9%
lkp-skl-d01      1832833       1823628    -0.5%     1806489    -1.4%
lkp-hsw-d01      1427913       1427287    -0.0%     1420226    -0.5%
lkp-sb02          750626        748615    -0.3%      746621    -0.5%

will-it-scale.page_fault3.processes (higher is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1    24382726      24400317 +0.1%       24668774 +1.2%
lkp-bdw-ex1     35399750      35683124 +0.8%       35829492 +1.2%
lkp-skl-2sp2    28136820      28068248 -0.2%       28147989 +0.0%
lkp-bdw-ep2     37269077      37459490 +0.5%       37373073 +0.3%
lkp-hsw-ep2     36224967      36114085 -0.3%       36104908 -0.3%
lkp-wsm-ep2     16820457      16911005 +0.5%       16968596 +0.9%
lkp-skl-d01      7721138       7725904 +0.1%        7756740 +0.5%
lkp-hsw-d01      7611979       7650928 +0.5%        7651323 +0.5%
lkp-sb02         3781546       3796502 +0.4%        3796827 +0.4%

will-it-scale.page_fault3.threads (higer is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1     1865820±3%   1900917±2%  +1.9%     1826245±4%  -2.1%
lkp-bdw-ex1      3094060      3148326     +1.8%     3150036     +1.8%
lkp-skl-2sp2     3952940      3953898     +0.0%     3989360     +0.9%
lkp-bdw-ep2      3420373±3%   3643964     +6.5%     3644910±5%  +6.6%
lkp-hsw-ep2      2609635±2%   2582310±3%  -1.0%     2780459     +6.5%
lkp-wsm-ep2      4395001      4417196     +0.5%     4432499     +0.9%
lkp-skl-d01      5363977      5400003     +0.7%     5411370     +0.9%
lkp-hsw-d01      5274131      5311294     +0.7%     5319359     +0.9%
lkp-sb02         2917314      2913004     -0.1%     2935286     +0.6%

will-it-scale.read1.processes (higer is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1    73762279±14%  69322519±10% -6.0%    69349855±13%  -6.0% (result unstable)
lkp-bdw-ex1     1.701e+08     1.704e+08    +0.1%    1.705e+08     +0.2%
lkp-skl-2sp2    63111570      63113953     +0.0%    63836573      +1.1%
lkp-bdw-ep2     79247409      79424610     +0.2%    78012656      -1.6%
lkp-hsw-ep2     67677026      68308800     +0.9%    67539106      -0.2%
lkp-wsm-ep2     13339630      13939817     +4.5%    13766865      +3.2%
lkp-skl-d01     10969487      10972650     +0.0%    no data
lkp-hsw-d01     9857342±2%    10080592±2%  +2.3%    10131560      +2.8%
lkp-sb02        5189076        5197473     +0.2%    5163253       -0.5%

will-it-scale.read1.threads (higher is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1    62468045±12%  73666726±7% +17.9%    79553123±12% +27.4% (result unstable)
lkp-bdw-ex1     1.62e+08      1.624e+08    +0.3%    1.614e+08     -0.3%
lkp-skl-2sp2    58319780      59181032     +1.5%    59821353      +2.6%
lkp-bdw-ep2     74057992      75698171     +2.2%    74990869      +1.3%
lkp-hsw-ep2     63672959      63639652     -0.1%    64387051      +1.1%
lkp-wsm-ep2     13489943      13526058     +0.3%    13259032      -1.7%
lkp-skl-d01     10297906      10338796     +0.4%    10407328      +1.1%
lkp-hsw-d01      9636721       9667376     +0.3%     9341147      -3.1%
lkp-sb02         4801938       4804496     +0.1%     4802290      +0.0%

will-it-scale.write1.processes (higer is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1    1.111e+08     1.104e+08±2%  -0.7%   1.122e+08±2%  +1.0%
lkp-bdw-ex1     1.392e+08     1.399e+08     +0.5%   1.397e+08     +0.4%
lkp-skl-2sp2     59369233      58994841     -0.6%    58715168     -1.1%
lkp-bdw-ep2      61820979      CPU throttle          63593123     +2.9%
lkp-hsw-ep2      57897587      57435605     -0.8%    56347450     -2.7%
lkp-wsm-ep2       7814203       7918017±2%  +1.3%     7669068     -1.9%
lkp-skl-d01       8886557       8971422     +1.0%     8818366     -0.8%
lkp-hsw-d01       9171001±5%    9189915     +0.2%     9483909     +3.4%
lkp-sb02          4475406       4475294     -0.0%     4501756     +0.6%

will-it-scale.write1.threads (higer is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1    1.058e+08     1.055e+08±2%  -0.2%   1.065e+08  +0.7%
lkp-bdw-ex1     1.316e+08     1.300e+08     -1.2%   1.308e+08  -0.6%
lkp-skl-2sp2     54492421      56086678     +2.9%    55975657  +2.7%
lkp-bdw-ep2      59360449      59003957     -0.6%    58101262  -2.1%
lkp-hsw-ep2      53346346±2%   52530876     -1.5%    52902487  -0.8%
lkp-wsm-ep2       7774006       7800092±2%  +0.3%     7558833  -2.8%
lkp-skl-d01       8346174       8235695     -1.3%     no data
lkp-hsw-d01       8636244       8655731     +0.2%     8658868  +0.3%
lkp-sb02          4181820       4204107     +0.5%     4182992  +0.0%

vm-scalability.anon-r-rand.throughput (higher is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1    11933873±3%   12356544±2%  +3.5%   12188624     +2.1%
lkp-bdw-ex1      7114424±2%    7330949±2%  +3.0%    7392419     +3.9%
lkp-skl-2sp2     6773277±5%    6492332±8%  -4.1%    6543962     -3.4%
lkp-bdw-ep2      7133846±4%    7233508     +1.4%    7013518±3%  -1.7%
lkp-hsw-ep2      4576626       4527098     -1.1%    4551679     -0.5%
lkp-wsm-ep2      2583599       2592492     +0.3%    2588039     +0.2%
lkp-hsw-d01       998199±2%    1028311     +3.0%    1006460±2%  +0.8%
lkp-sb02          570572        567854     -0.5%     568449     -0.4%

vm-scalability.anon-r-rand-mt.throughput (higher is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1     1789419       1787830     -0.1%    1788208     -0.1%
lkp-bdw-ex1      3492595±2%    3554966±2%  +1.8%    3558835±3%  +1.9%
lkp-skl-2sp2     3856238±2%    3975403±4%  +3.1%    3994600     +3.6%
lkp-bdw-ep2      3726963±11%   3809292±6%  +2.2%    3871924±4%  +3.9%
lkp-hsw-ep2      2131760±3%    2033578±4%  -4.6%    2130727±6%  -0.0%
lkp-wsm-ep2      2369731       2368384     -0.1%    2370252     +0.0%
lkp-skl-d01      1207128       1206220     -0.1%    1205801     -0.1%
lkp-hsw-d01       964317        992329±2%  +2.9%     992099±2%  +2.9%
lkp-sb02          567137        567346     +0.0%     566144     -0.2%

vm-scalability.lru-file-mmap-read.throughput (higher is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1    19560469±6%   23018999     +17.7%   23418800     +19.7%
lkp-bdw-ex1     17769135±14%  26141676±3%  +47.1%   26284723±5%  +47.9%
lkp-skl-2sp2    14056512      13578884      -3.4%   13146214      -6.5%
lkp-bdw-ep2     15336542      14737654      -3.9%   14088159      -8.1%
lkp-hsw-ep2     16275498      15756296      -3.2%   15018090      -7.7%
lkp-wsm-ep2     11272160      11237231      -0.3%   11310047      +0.3%
lkp-skl-d01      7322119       7324569      +0.0%    7184148      -1.9%
lkp-hsw-d01      6449234       6404542      -0.7%    6356141      -1.4%
lkp-sb02         3517943       3520668      +0.1%    3527309      +0.3%

vm-scalability.lru-file-mmap-read-rand.throughput (higher is better)

machine         batch=31      batch=63             batch=127
lkp-skl-4sp1     1689052       1697553  +0.5%       1698726  +0.6%
lkp-bdw-ex1      1675246       1699764  +1.5%       1712226  +2.2%
lkp-skl-2sp2     1800533       1799749  -0.0%       1800581  +0.0%
lkp-bdw-ep2      1807422       1807758  +0.0%       1804932  -0.1%
lkp-hsw-ep2      1809807       1808781  -0.1%       1807811  -0.1%
lkp-wsm-ep2      1800198       1802434  +0.1%       1801236  +0.1%
lkp-skl-d01       696689        695537  -0.2%        694106  -0.4%
lkp-hsw-d01       698364        698666  +0.0%        696686  -0.2%
lkp-sb02          258939        258787  -0.1%        258199  -0.3%

Link: http://lkml.kernel.org/r/20180711055855.29072-1-aaron.lu@intel.com
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Suggested-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Kemi Wang <kemi.wang@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Danny Lin <danny@kdrag0n.dev>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 09:52:40 +00:00
Minchan Kim
e13c88efb8
mm: introduce deactivate_page
perprocess reclaims needs to deactivate file pages from active LRU
when echo file > /proc/<pid>/reclaim.
Add deactivate_file pages.

Bug: 131016077
Bug: 153444106
(cherry picked from b07eab27085611203ad359b7f4eecd138d7d771a)
Change-Id: I06fed20103671e4ca6fb8663d5029736442162a5
Signed-off-by: Minchan Kim <minchan@google.com>
Signed-off-by: Martin Liu <liumartin@google.com>
Signed-off-by: Andrzej Perczak <linux@andrzejperczak.com>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 09:52:32 +00:00
Vlastimil Babka
407183bd19
mm, compaction: raise compaction priority after it withdrawns
Mike Kravetz reports that "hugetlb allocations could stall for minutes or
hours when should_compact_retry() would return true more often then it
should.  Specifically, this was in the case where compact_result was
COMPACT_DEFERRED and COMPACT_PARTIAL_SKIPPED and no progress was being
made."

The problem is that the compaction_withdrawn() test in
should_compact_retry() includes compaction outcomes that are only possible
on low compaction priority, and results in a retry without increasing the
priority.  This may result in furter reclaim, and more incomplete
compaction attempts.

With this patch, compaction priority is raised when possible, or
should_compact_retry() returns false.

The COMPACT_SKIPPED result doesn't really fit together with the other
outcomes in compaction_withdrawn(), as that's a result caused by
insufficient order-0 pages, not due to low compaction priority.  With this
patch, it is moved to a new compaction_needs_reclaim() function, and for
that outcome we keep the current logic of retrying if it looks like
reclaim will be able to help.

Bug: 156785617
Link: http://lkml.kernel.org/r/20190806014744.15446-4-mike.kravetz@oracle.com
Reported-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Tested-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Minchan Kim <minchan@google.com>
Change-Id: I67134003597caa963d5ecff7e2a42ef101e3aa4a
Signed-off-by: Andrzej Perczak <linux@andrzejperczak.com>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 09:52:24 +00:00
tarsin
1e550e19b2
mm: damon: Optimize reclaim parameters
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 09:36:47 +00:00
UtsavBalar1231
6cad89a148
mm: damon: Enable DAMON-based reclaim by default
Change-Id: I23da7fed2549c5d8ba9b62874056e74a201186b3
Signed-off-by: UtsavBalar1231 <utsavbalar1231@gmail.com>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 09:36:47 +00:00
Dark-Matter7232
1923f50f3d
mm/damon: reclaim: Adapt to downstream walk_system_ram_res()
Signed-off-by: Dark-Matter7232 <kerneldeveloper7232@gmail.com>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 09:36:47 +00:00
Dark-Matter7232
0f028d37e8
mm/damon: fix build
Signed-off-by: Dark-Matter7232 <kerneldeveloper7232@gmail.com>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 09:36:47 +00:00
UtsavBalar1231
171535f8a3
mm: damon: Avoid using mm_walk_ops API
- 4.19 kernel doesn't support mm_walk_ops structure
so revert back to inlining mm_walk structures inside methods

Change-Id: I87986a9e95468b76e4c68cb6b368599cc1494549
Signed-off-by: UtsavBalar1231 <utsavbalar1231@gmail.com>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 09:36:46 +00:00
UtsavBalar1231
68823c43f1
mm: madvise: Avoid using mm_walk_ops API
- 4.19 kernel doesn't support mm_walk_ops structure
so revert back to inlining mm_walk structures inside methods

Change-Id: Id9061bde347d5c4050025c7a8fce673677bfa9f2
Signed-off-by: UtsavBalar1231 <utsavbalar1231@gmail.com>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 09:36:46 +00:00
zhong jiang
88dc2cfd55
UPSTREAM: mm: fix trying to reclaim unevictable lru page when calling madvise_pageout
Recently, I hit the following issue when running upstream.

  kernel BUG at mm/vmscan.c:1521!
  invalid opcode: 0000 [#1] SMP KASAN PTI
  CPU: 0 PID: 23385 Comm: syz-executor.6 Not tainted 5.4.0-rc4+ #1
  RIP: 0010:shrink_page_list+0x12b6/0x3530 mm/vmscan.c:1521
  Call Trace:
   reclaim_pages+0x499/0x800 mm/vmscan.c:2188
   madvise_cold_or_pageout_pte_range+0x58a/0x710 mm/madvise.c:453
   walk_pmd_range mm/pagewalk.c:53 [inline]
   walk_pud_range mm/pagewalk.c:112 [inline]
   walk_p4d_range mm/pagewalk.c:139 [inline]
   walk_pgd_range mm/pagewalk.c:166 [inline]
   __walk_page_range+0x45a/0xc20 mm/pagewalk.c:261
   walk_page_range+0x179/0x310 mm/pagewalk.c:349
   madvise_pageout_page_range mm/madvise.c:506 [inline]
   madvise_pageout+0x1f0/0x330 mm/madvise.c:542
   madvise_vma mm/madvise.c:931 [inline]
   __do_sys_madvise+0x7d2/0x1600 mm/madvise.c:1113
   do_syscall_64+0x9f/0x4c0 arch/x86/entry/common.c:290
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

madvise_pageout() accesses the specified range of the vma and isolates
them, then runs shrink_page_list() to reclaim its memory.  But it also
isolates the unevictable pages to reclaim.  Hence, we can catch the
cases in shrink_page_list().

The root cause is that we scan the page tables instead of specific LRU
list.  and so we need to filter out the unevictable lru pages from our
end.

Link: http://lkml.kernel.org/r/1572616245-18946-1-git-send-email-zhongjiang@huawei.com
Fixes: 1a4e58cce84e ("mm: introduce MADV_PAGEOUT")
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: UtsavBalar1231 <utsavbalar1231@gmail.com>
Change-Id: I84ecf1ed9f7d9de14df1798922183fb637d75adc
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 09:36:46 +00:00
Mike Rapoport
2be36de245
mm/madvise: reduce code duplication in error handling paths
madvise_behavior() converts -ENOMEM to -EAGAIN in several places using
identical code.

Move that code to a common error handling path.

No functional changes.

Link: http://lkml.kernel.org/r/1564640896-1210-1-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Pankaj Gupta <pagupta@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 09:36:46 +00:00
Edgar Arriaga
df3a67460e
FROMLIST: mm/madvise: replace ptrace attach requirement for process_madvise
process_madvise currently requires ptrace attach capability.
PTRACE_MODE_ATTACH gives one process complete control over another
process. It effectively removes the security boundary between the
two processes (in one direction). Granting ptrace attach capability
even to a system process is considered dangerous since it creates an
attack surface. This severely limits the usage of this API.
The operations process_madvise can perform do not affect the correctness
of the operation of the target process; they only affect where the data
is physically located (and therefore, how fast it can be accessed).
What we want is the ability for one process to influence another process
in order to optimize performance across the entire system while leaving
the security boundary intact.
Replace PTRACE_MODE_ATTACH with a combination of PTRACE_MODE_READ
and CAP_SYS_NICE. PTRACE_MODE_READ to prevent leaking ASLR metadata
and CAP_SYS_NICE for influencing process performance.

Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: David Rientjes <rientjes@google.com>
Link: https://lore.kernel.org/lkml/202101111033.2D03EA97@keescook/T/#u

Test: built and flashed kernel
Bug: 153444106
Signed-off-by: Edgar Arriaga Garcia <edgararriaga@google.com>
Change-Id: I3624a8b0697d70f23587c1dcb746ba753c301f45
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 09:36:46 +00:00
Edgar Arriaga
5e6f2afbcf
UPSTREAM: mm/madvise: remove racy mm ownership check
Jann spotted the security hole due to race of mm ownership check.

If the task is sharing the mm_struct but goes through execve() before
mm_access(), it could skip process_madvise_behavior_valid check.  That
makes *any advice hint* to reach into the remote process.

This patch removes the mm ownership check.  With it, it will lose the
ability that local process could give *any* advice hint with vector
interface for some reason (e.g., performance).  Since there is no
concrete example in upstream yet, it would be better to remove the
abiliity at this moment and need to review when such new advice comes
up.

Fixes: ecb8ac8b1f14 ("mm/madvise: introduce process_madvise() syscall: an external memory hinting API")
Reported-by: Jann Horn <jannh@google.com>
Suggested-by: Jann Horn <jannh@google.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

(cherry picked from commit a68a0262abdaa251e12c53715f48e698a18ef402)

Bug: 153444106
Test: Built and flashed kernel

Signed-off-by: Edgar Arriaga Garcia <edgararriaga@google.com>
Change-Id: I49b1a581d1d6b651b46e0e7024cf61bce29578ba
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 09:36:46 +00:00
Edgar Arriaga
a39ffe1406
FROMLIST: mm/madvise: fix memory leak from process_madvise
The eary return in process_madvise will produce memory leak.
Fix it.

Fixes: ecb8ac8b1f14 ("mm/madvise: introduce process_madvise() syscall: an external memory hinting API")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Link: https://lore.kernel.org/linux-mm/20201116155132.GA3805951@google.com/

Test: Built and flashed kernel
Signed-off-by: Edgar Arriaga Garcia <edgararriaga@google.com>
Change-Id: Id1f7df48debe7fd55e51bf99257e1a2c6d97b285
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 09:36:46 +00:00
Edgar Arriaga García
e4493a4b48
BACKPORT: mm/madvise: introduce process_madvise() syscall: an external memory hinting API
There is usecase that System Management Software(SMS) want to give
a memory hint like MADV_[COLD|PAGEEOUT] to other processes and
in the case of Android, it is the ActivityManagerService.

It's similar in spirit to madvise(MADV_WONTNEED), but the information
required to make the reclaim decision is not known to the app. Instead,
it is known to the centralized userspace daemon(ActivityManagerService),
and that daemon must be able to initiate reclaim on its own without
any app involvement.

To solve the issue, this patch introduces a new syscall process_madvise(2).
It uses pidfd of an external process to give the hint.

 int process_madvise(int pidfd, void *addr, size_t length, int advise,
			unsigned long flag);

Since it could affect other process's address range, only privileged
process(CAP_SYS_PTRACE) or something else(e.g., being the same UID)
gives it the right to ptrace the process could use it successfully.
The flag argument is reserved for future use if we need to extend the
API.

I think supporting all hints madvise has/will supported/support to
process_madvise is rather risky. Because we are not sure all hints make
sense from external process and implementation for the hint may rely on
the caller being in the current context so it could be error-prone.
Thus, I just limited hints as MADV_[COLD|PAGEOUT] in this patch.

If someone want to add other hints, we could hear hear the usecase and
review it for each hint. It's safer for maintenance rather than
introducing a buggy syscall but hard to fix it later.

[1] https://developer.android.com/topic/performance/memory"
[2] process_getinfo for getting the cookie which is updated whenever
    vma of process address layout are changed - Daniel Colascione
- https://lore.kernel.org/lkml/20190520035254.57579-1-minchan@kernel.org/T/#m7694416fd179b2066a2c62b5b139b14e3894e224
[3] anonymous fd which is used for the object(i.e., address range)
    validation - Michal Hocko
- https://lore.kernel.org/lkml/20200120112722.GY18451@dhcp22.suse.cz/

Link: http://lkml.kernel.org/r/20200302193630.68771-3-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Christian Brauner <christian@brauner.io>
Cc: Daniel Colascione <dancol@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: John Dias <joaodias@google.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Sandeep Patil <sspatil@google.com>
Cc: SeongJae Park <sj38.park@gmail.com>
Cc: SeongJae Park <sjpark@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Tim Murray <timmurray@google.com>
Cc: <linux-man@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

(cherry picked from commit ecb8ac8b1f146915aa6b96449b66dd48984caacc)

Conflicts:
    arch/alpha/kernel/syscalls/syscall.tbl
    arch/ia64/kernel/syscalls/syscall.tbl
    arch/m68k/kernel/syscalls/syscall.tbl
    arch/microblaze/kernel/syscalls/syscall.tbl
    arch/mips/kernel/syscalls/syscall_n32.tbl
    arch/mips/kernel/syscalls/syscall_n64.tbl
    arch/parisc/kernel/syscalls/syscall.tbl
    arch/powerpc/kernel/syscalls/syscall.tbl
    arch/s390/kernel/syscalls/syscall.tbl
    arch/sh/kernel/syscalls/syscall.tbl
    arch/sparc/kernel/syscalls/syscall.tbl
    mm/madvise.c

1. __NR_compat_syscalls in arch/arm64/include/asm/unistd.h modified to match latest version to avoid
clobbering old number.
2. Dropped syscall.tbl, syscall_n32, syscall_n64 files for architectures
not present in current kernel.
3. __NR_process_madvise in arch/arm64/include/asm/unistd32.h modified to
match latest mm tree.
4. Added include for uio.h lib which is needed for UIO_FASTIOV and iovec

Bug: 153444106
Test: Built kernel
Signed-off-by: Edgar Arriaga García <edgararriaga@google.com>

Change-Id: Icfff940abebcf290c3111239989ed40a407cf2a6
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 09:36:45 +00:00
Minchan Kim
5478448d67
BACKPORT: mm/madvise: pass mm to do_madvise
Now, we have MADV_PAGEOUT and MADV_COLD as madvise hinting API.  With
that, application could give hints to kernel what memory range are
preferred to be reclaimed.  However, in some platform(e.g., Android), the
information required to make the hinting decision is not known to the app.
Instead, it is known to a centralized userspace daemon(e.g.,
ActivityManagerService), and that daemon must be able to initiate reclaim
on its own without any app involvement.

To solve the concern, this patch introduces new syscall -
process_madvise(2).  Bascially, it's same with madvise(2) syscall but it
has some differences.

1. It needs pidfd of target process to provide the hint

2. It supports only MADV_{COLD|PAGEOUT|MERGEABLE|UNMEREABLE} at this
   moment.  Other hints in madvise will be opened when there are explicit
   requests from community to prevent unexpected bugs we couldn't support.

3. Only privileged processes can do something for other process's
   address space.

For more detail of the new API, please see "mm: introduce external memory
hinting API" description in this patchset.

This patch (of 3):

In upcoming patches, do_madvise will be called from external process
context so we shouldn't asssume "current" is always hinted process's
task_struct.

Furthermore, we must not access mm_struct via task->mm, but obtain it via
access_mm() once (in the following patch) and only use that pointer [1],
so pass it to do_madvise() as well.  Note the vma->vm_mm pointers are
safe, so we can use them further down the call stack.

And let's pass current->mm as arguments of do_madvise so it shouldn't
change existing behavior but prepare next patch to make review easy.

[vbabka@suse.cz: changelog tweak]
[minchan@kernel.org: use current->mm for io_uring]
  Link: http://lkml.kernel.org/r/20200423145215.72666-1-minchan@kernel.org
[akpm@linux-foundation.org: fix it for upstream changes]
[akpm@linux-foundation.org: whoops]
[rdunlap@infradead.org: add missing includes]

Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jann Horn <jannh@google.com>
Cc: Tim Murray <timmurray@google.com>
Cc: Daniel Colascione <dancol@google.com>
Cc: Sandeep Patil <sspatil@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: John Dias <joaodias@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: SeongJae Park <sj38.park@gmail.com>
Cc: Christian Brauner <christian@brauner.io>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: SeongJae Park <sjpark@amazon.de>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Florian Weimer <fw@deneb.enyo.de>
Cc: <linux-man@vger.kernel.org>
Link: https://lkml.kernel.org/r/20200901000633.1920247-1-minchan@kernel.org
Link: http://lkml.kernel.org/r/20200622192900.22757-1-minchan@kernel.org
Link: http://lkml.kernel.org/r/20200302193630.68771-2-minchan@kernel.org
Link: http://lkml.kernel.org/r/20200622192900.22757-2-minchan@kernel.org
Link: https://lkml.kernel.org/r/20200901000633.1920247-2-minchan@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

(cherry picked from commit 0726b01e70455f9900ab524117c7b520d197dc8c)

Conflicts:
    fs/io_uring.c
    mm/madvise.c

1. fs/io_uring.c changes are not included because the file is missing in 4.14.
2. mm/madvise.c did not need additional includes
3. mm/madvise.c refactored to use mm instead
of current->mm as that is what the patch changed.
4. mm/madvise.c Keep mmget_still_valid check that early outs from madvise
if core dumping at the same time we try to madvise.
5. mm/madvise.c: did not add mm for madvise_willneed as it was not
needed and causing to have a unused variable error when compiling.

Bug: 153444106
Test: Built kernel

Signed-off-by: Edgar Arriaga García <edgararriaga@google.com>
Change-Id: I11b99220ae2a5e94cf46cb8b1f28fb109b4a25da
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 09:36:45 +00:00
Edgar Arriaga García
8b658cd540
UPSTREAM: mm: check that mm is still valid in madvise()
IORING_OP_MADVISE can end up basically doing mprotect() on the VM of
another process, which means that it can race with our crazy core dump
handling which accesses the VM state without holding the mmap_sem
(because it incorrectly thinks that it is the final user).

This is clearly a core dumping problem, but we've never fixed it the
right way, and instead have the notion of "check that the mm is still
ok" using mmget_still_valid() after getting the mmap_sem for writing in
any situation where we're not the original VM thread.

See commit 04f5866e41fb ("coredump: fix race condition between
mmget_not_zero()/get_task_mm() and core dumping") for more background on
this whole mmget_still_valid() thing.  You might want to have a barf bag
handy when you do.

We're discussing just fixing this properly in the only remaining core
dumping routines.  But even if we do that, let's make do_madvise() do
the right thing, and then when we fix core dumping, we can remove all
these mmget_still_valid() checks.

Reported-and-tested-by: Jann Horn <jannh@google.com>
Fixes: c1ca757bd6f4 ("io_uring: add IORING_OP_MADVISE")
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

(cherry picked from commit bc0c4d1e176eeb614dc8734fc3ace34292771f11)

Bug: 153444106
Test: Built kernel

Signed-off-by: Edgar Arriaga García <edgararriaga@google.com>
Change-Id: I9e300af00dd41d49be17abd545ac6572dbe4b797
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 09:36:45 +00:00
Michal Hocko
07be66e42e
UPSTREAM: mm: do not allow MADV_PAGEOUT for CoW pages
Jann has brought up a very interesting point [1].  While shared pages
are excluded from MADV_PAGEOUT normally, CoW pages can be easily
reclaimed that way.  This can lead to all sorts of hard to debug
problems.  E.g.  performance problems outlined by Daniel [2].

There are runtime environments where there is a substantial memory
shared among security domains via CoW memory and a easy to reclaim way
of that memory, which MADV_{COLD,PAGEOUT} offers, can lead to either
performance degradation in for the parent process which might be more
privileged or even open side channel attacks.

The feasibility of the latter is not really clear to me TBH but there is
no real reason for exposure at this stage.  It seems there is no real
use case to depend on reclaiming CoW memory via madvise at this stage so
it is much easier to simply disallow it and this is what this patch
does.  Put it simply MADV_{PAGEOUT,COLD} can operate only on the
exclusively owned memory which is a straightforward semantic.

[1] http://lkml.kernel.org/r/CAG48ez0G3JkMq61gUmyQAaCq=_TwHbi1XKzWRooxZkv08PQKuw@mail.gmail.com
[2] http://lkml.kernel.org/r/CAKOZueua_v8jHCpmEtTB6f3i9e2YnmX4mqdYVWhV4E=Z-n+zRQ@mail.gmail.com

Fixes: 9c276cc65a58 ("mm: introduce MADV_COLD")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Daniel Colascione <dancol@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: "Joel Fernandes (Google)" <joel@joelfernandes.org>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200312082248.GS23944@dhcp22.suse.cz
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

(cherry picked from 12e967fd8e4e6c3d275b4c69c890adc838891300)

Bug: 153444106
Test: Built kernel
Signed-off-by: Edgar Arriaga García <edgararriaga@google.com>
Change-Id: I18d197e4b241405e6c8051cc7a5e7cbd3a1ee5b9
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 09:36:44 +00:00
Minchan Kim
d77065c051
UPSTREAM: mm: validate pmd after splitting
syzbot reported the following KASAN splat:

  general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN
  KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
  CPU: 1 PID: 6826 Comm: syz-executor142 Not tainted 5.9.0-rc4-syzkaller #0
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
  RIP: 0010:__lock_acquire+0x84/0x2ae0 kernel/locking/lockdep.c:4296
  Code: ff df 8a 04 30 84 c0 0f 85 e3 16 00 00 83 3d 56 58 35 08 00 0f 84 0e 17 00 00 83 3d 25 c7 f5 07 00 74 2c 4c 89 e8 48 c1 e8 03 <80> 3c 30 00 74 12 4c 89 ef e8 3e d1 5a 00 48 be 00 00 00 00 00 fc
  RSP: 0018:ffffc90004b9f850 EFLAGS: 00010006
  Call Trace:
    lock_acquire+0x140/0x6f0 kernel/locking/lockdep.c:5006
    __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
    _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151
    spin_lock include/linux/spinlock.h:354 [inline]
    madvise_cold_or_pageout_pte_range+0x52f/0x25c0 mm/madvise.c:389
    walk_pmd_range mm/pagewalk.c:89 [inline]
    walk_pud_range mm/pagewalk.c:160 [inline]
    walk_p4d_range mm/pagewalk.c:193 [inline]
    walk_pgd_range mm/pagewalk.c:229 [inline]
    __walk_page_range+0xe7b/0x1da0 mm/pagewalk.c:331
    walk_page_range+0x2c3/0x5c0 mm/pagewalk.c:427
    madvise_pageout_page_range mm/madvise.c:521 [inline]
    madvise_pageout mm/madvise.c:557 [inline]
    madvise_vma mm/madvise.c:946 [inline]
    do_madvise+0x12d0/0x2090 mm/madvise.c:1145
    __do_sys_madvise mm/madvise.c:1171 [inline]
    __se_sys_madvise mm/madvise.c:1169 [inline]
    __x64_sys_madvise+0x76/0x80 mm/madvise.c:1169
    do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
    entry_SYSCALL_64_after_hwframe+0x44/0xa9

The backing vma was shmem.

In case of split page of file-backed THP, madvise zaps the pmd instead
of remapping of sub-pages.  So we need to check pmd validity after
split.

Reported-by: syzbot+ecf80462cb7d5d552bc7@syzkaller.appspotmail.com
Fixes: 1a4e58cce84e ("mm: introduce MADV_PAGEOUT")
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

(cherry picked from commit ce2684254bd4818ca3995c0d021fb62c4cf10a19)

Bug: 153444106
Test: Built kernel

Signed-off-by: Edgar Arriaga García <edgararriaga@google.com>
Change-Id: I8ae135a797b82a333057a68c12df85a41c15747f
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 09:36:44 +00:00
Edgar Arriaga
4b0678dbf5
UPSTREAM: mm: factor out common parts between MADV_COLD and MADV_PAGEOUT
There are many common parts between MADV_COLD and MADV_PAGEOUT.
This patch factor them out to save code duplication.

Link: http://lkml.kernel.org/r/20190726023435.214162-6-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Daniel Colascione <dancol@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: kbuild test robot <lkp@intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

(cherry picked from commit d616d5126503967bf365db0711ee3c78b356efe9)

Bug: 153444106
Test: Built kernel

Signed-off-by: Edgar Arriaga García <edgararriaga@google.com>
Change-Id: I125cdc8410d66d38907a9c74668306a32e7df55e
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 09:36:44 +00:00
Edgar Arriaga García
328f23e54e
UPSTREAM: mm: introduce MADV_PAGEOUT
When a process expects no accesses to a certain memory range for a long
time, it could hint kernel that the pages can be reclaimed instantly but
data should be preserved for future use.  This could reduce workingset
eviction so it ends up increasing performance.

This patch introduces the new MADV_PAGEOUT hint to madvise(2) syscall.
MADV_PAGEOUT can be used by a process to mark a memory range as not
expected to be used for a long time so that kernel reclaims *any LRU*
pages instantly.  The hint can help kernel in deciding which pages to
evict proactively.

A note: It doesn't apply SWAP_CLUSTER_MAX LRU page isolation limit
intentionally because it's automatically bounded by PMD size.  If PMD
size(e.g., 256) makes some trouble, we could fix it later by limit it to
SWAP_CLUSTER_MAX[1].

- man-page material

MADV_PAGEOUT (since Linux x.x)

Do not expect access in the near future so pages in the specified
regions could be reclaimed instantly regardless of memory pressure.
Thus, access in the range after successful operation could cause
major page fault but never lose the up-to-date contents unlike
MADV_DONTNEED. Pages belonging to a shared mapping are only processed
if a write access is allowed for the calling process.

MADV_PAGEOUT cannot be applied to locked pages, Huge TLB pages, or
VM_PFNMAP pages.

[1] https://lore.kernel.org/lkml/20190710194719.GS29695@dhcp22.suse.cz/

[minchan@kernel.org: clear PG_active on MADV_PAGEOUT]
Link: http://lkml.kernel.org/r/20190802200643.GA181880@google.com

(cherry-picked from commit 1a4e58cce84ee88129d5d49c064bd2852b481357)

Bug: 153444106
Test: Built kernel

Signed-off-by: Edgar Arriaga García <edgararriaga@google.com>
Change-Id: Id400fe31150226684ffb6f37f399c4867490656e
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 09:36:44 +00:00
Edgar Arriaga García
083dbe75d0
BACKPORT: mm: introduce MADV_COLD
When a process expects no accesses to a certain memory range, it could
give a hint to kernel that the pages can be reclaimed when memory pressure
happens but data should be preserved for future use.  This could reduce
workingset eviction so it ends up increasing performance.

This patch introduces the new MADV_COLD hint to madvise(2) syscall.
MADV_COLD can be used by a process to mark a memory range as not expected
to be used in the near future.  The hint can help kernel in deciding which
pages to evict early during memory pressure.

It works for every LRU pages like MADV_[DONTNEED|FREE]. IOW, It moves

        active file page -> inactive file LRU
        active anon page -> inacdtive anon LRU

Unlike MADV_FREE, it doesn't move active anonymous pages to inactive file
LRU's head because MADV_COLD is a little bit different symantic.
MADV_FREE means it's okay to discard when the memory pressure because the
content of the page is *garbage* so freeing such pages is almost zero
overhead since we don't need to swap out and access afterward causes just
minor fault.  Thus, it would make sense to put those freeable pages in
inactive file LRU to compete other used-once pages.  It makes sense for
implmentaion point of view, too because it's not swapbacked memory any
longer until it would be re-dirtied.  Even, it could give a bonus to make
them be reclaimed on swapless system.  However, MADV_COLD doesn't mean
garbage so reclaiming them requires swap-out/in in the end so it's bigger
cost.  Since we have designed VM LRU aging based on cost-model, anonymous
cold pages would be better to position inactive anon's LRU list, not file
LRU.  Furthermore, it would help to avoid unnecessary scanning if system
doesn't have a swap device.  Let's start simpler way without adding
complexity at this moment.  However, keep in mind, too that it's a caveat
that workloads with a lot of pages cache are likely to ignore MADV_COLD on
anonymous memory because we rarely age anonymous LRU lists.

* man-page material

MADV_COLD (since Linux x.x)

Pages in the specified regions will be treated as less-recently-accessed
compared to pages in the system with similar access frequencies.  In
contrast to MADV_FREE, the contents of the region are preserved regardless
of subsequent writes to pages.

MADV_COLD cannot be applied to locked pages, Huge TLB pages, or VM_PFNMAP
pages.

[akpm@linux-foundation.org: resolve conflicts with hmm.git]
Link: http://lkml.kernel.org/r/20190726023435.214162-2-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: kbuild test robot <lkp@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Daniel Colascione <dancol@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

(cherry picked from commit 9c276cc65a58faf98be8e56962745ec99ab87636)

Conflicts:
    include/asm-generic/tlb.h

1. Added tlb_change_page_size function from commit ed6a79352cad00e9a49d6e438be40e45107207bf
which was required by this patch.

2. the lru_deactivate_pvecs and other swap.c changes are skipped as they already
existed in the repo, they were backported in change-id I06fed20103671e4ca6fb8663d5029736442162a5

Bug: 153444106
Test: Built kernel
Signed-off-by: Edgar Arriaga García <edgararriaga@google.com>
Change-Id: I8f0f9d54e2f3d0ffe75c54f4db67e73f60083482
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 09:36:44 +00:00
Yang Shi
a884e01a78
UPSTREAM: mm: madvise: fix vma user-after-free
commit 7867fd7cc44e63c6673cd0f8fea155456d34d0de upstream.

The syzbot reported the below use-after-free:

  BUG: KASAN: use-after-free in madvise_willneed mm/madvise.c:293 [inline]
  BUG: KASAN: use-after-free in madvise_vma mm/madvise.c:942 [inline]
  BUG: KASAN: use-after-free in do_madvise.part.0+0x1c8b/0x1cf0 mm/madvise.c:1145
  Read of size 8 at addr ffff8880a6163eb0 by task syz-executor.0/9996

  CPU: 0 PID: 9996 Comm: syz-executor.0 Not tainted 5.9.0-rc1-syzkaller #0
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
  Call Trace:
    __dump_stack lib/dump_stack.c:77 [inline]
    dump_stack+0x18f/0x20d lib/dump_stack.c:118
    print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383
    __kasan_report mm/kasan/report.c:513 [inline]
    kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
    madvise_willneed mm/madvise.c:293 [inline]
    madvise_vma mm/madvise.c:942 [inline]
    do_madvise.part.0+0x1c8b/0x1cf0 mm/madvise.c:1145
    do_madvise mm/madvise.c:1169 [inline]
    __do_sys_madvise mm/madvise.c:1171 [inline]
    __se_sys_madvise mm/madvise.c:1169 [inline]
    __x64_sys_madvise+0xd9/0x110 mm/madvise.c:1169
    do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
    entry_SYSCALL_64_after_hwframe+0x44/0xa9

  Allocated by task 9992:
    kmem_cache_alloc+0x138/0x3a0 mm/slab.c:3482
    vm_area_alloc+0x1c/0x110 kernel/fork.c:347
    mmap_region+0x8e5/0x1780 mm/mmap.c:1743
    do_mmap+0xcf9/0x11d0 mm/mmap.c:1545
    vm_mmap_pgoff+0x195/0x200 mm/util.c:506
    ksys_mmap_pgoff+0x43a/0x560 mm/mmap.c:1596
    do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
    entry_SYSCALL_64_after_hwframe+0x44/0xa9

  Freed by task 9992:
    kmem_cache_free.part.0+0x67/0x1f0 mm/slab.c:3693
    remove_vma+0x132/0x170 mm/mmap.c:184
    remove_vma_list mm/mmap.c:2613 [inline]
    __do_munmap+0x743/0x1170 mm/mmap.c:2869
    do_munmap mm/mmap.c:2877 [inline]
    mmap_region+0x257/0x1780 mm/mmap.c:1716
    do_mmap+0xcf9/0x11d0 mm/mmap.c:1545
    vm_mmap_pgoff+0x195/0x200 mm/util.c:506
    ksys_mmap_pgoff+0x43a/0x560 mm/mmap.c:1596
    do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
    entry_SYSCALL_64_after_hwframe+0x44/0xa9

It is because vma is accessed after releasing mmap_lock, but someone
else acquired the mmap_lock and the vma is gone.

Releasing mmap_lock after accessing vma should fix the problem.

Fixes: 692fe62433d4c ("mm: Handle MADV_WILLNEED through vfs_fadvise()")
Reported-by: syzbot+b90df26038d1d5d85c97@syzkaller.appspotmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: <stable@vger.kernel.org>	[5.4+]
Link: https://lkml.kernel.org/r/20200816141204.162624-1-shy828301@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: UtsavBalar1231 <utsavbalar1231@gmail.com>
Change-Id: I65ea23f83f7128d20ddc178965ceb5948272c6c5
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 09:36:43 +00:00
Jan Kara
518347c3aa
UPSTREAM: mm: Handle MADV_WILLNEED through vfs_fadvise()
Currently handling of MADV_WILLNEED hint calls directly into readahead
code. Handle it by calling vfs_fadvise() instead so that filesystem can
use its ->fadvise() callback to acquire necessary locks or otherwise
prepare for the request.

Suggested-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Boaz Harrosh <boazh@netapp.com>
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: UtsavBalar1231 <utsavbalar1231@gmail.com>
Change-Id: I4c0f564139668b15595ce3d0a165c5cb756ef169
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 09:36:43 +00:00
Hailong Tu
60b5f5cc09
FROMLIST: mm/damon/reclaim: Fix the timer always stays active
The timer stays active even if the reclaim mechanism is never enabled.
It is unnecessary overhead can be completely avoided by using module_param_cb() for enabled flag.

Signed-off-by: Hailong Tu <tuhailong@gmail.com>

Link: https://lore.kernel.org/all/20220421125910.1052459-1-tuhailong@gmail.com/

Bug: 228223814
Signed-off-by: Hailong Tu <tuhailong@oppo.com>
Change-Id: I77591e41ce424ce16a4a5c70e7a86cdae996a354
Signed-off-by: azrim <mirzaspc@gmail.com>
2022-07-31 09:36:43 +00:00