mm, swap: introduce SWP_SYNCHRONOUS_IO

If rw-page based fast storage is used for swap devices, we need to
detect it to enhance swap IO operations.  This patch is preparation for
optimizing of swap-in operation with next patch.

Change-Id: I25b0b93441fc602b9a697e5ee231eb7b5dd3dbfe
Link: http://lkml.kernel.org/r/1505886205-9671-4-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Git-commit: 539a6fea7fdcade532bd3e77be2862a683f8f0c9
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
This commit is contained in:
Minchan Kim 2017-11-15 17:33:04 -08:00 committed by Gerrit - the friendly Code Review server
parent b5f80c8c54
commit ef97cef29a
2 changed files with 5 additions and 1 deletions

View File

@ -171,8 +171,9 @@ enum {
SWP_AREA_DISCARD = (1 << 8), /* single-time swap area discards */
SWP_PAGE_DISCARD = (1 << 9), /* freed swap page-cluster discards */
SWP_STABLE_WRITES = (1 << 10), /* no overwrite PG_writeback pages */
SWP_SYNCHRONOUS_IO = (1 << 11), /* synchronous IO is efficient */
/* add others here before... */
SWP_SCANNING = (1 << 11), /* refcount in scan_swap_map */
SWP_SCANNING = (1 << 12), /* refcount in scan_swap_map */
};
#define SWAP_CLUSTER_MAX 32UL

View File

@ -3169,6 +3169,9 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
if (bdi_cap_stable_pages_required(inode_to_bdi(inode)))
p->flags |= SWP_STABLE_WRITES;
if (bdi_cap_synchronous_io(inode_to_bdi(inode)))
p->flags |= SWP_SYNCHRONOUS_IO;
if (p->bdev && blk_queue_nonrot(bdev_get_queue(p->bdev))) {
int cpu;
unsigned long ci, nr_cluster;