malhuda/msm-4.14
1
0
Fork 0
mirror of https://github.com/rd-stuffs/msm-4.14.git synced 2025-02-20 11:45:48 +08:00
Code Issues Actions Packages Projects Releases Wiki Activity

cpu-hotplug: Keep atleast 1 online and un-isolated CPU

Browse Source 
The PM_QOS_CPU_DMA_LATENCY vote attached to an IRQ is discarded,
if it is affined to an isolated CPU. So we need atleast 1 CPU
in online and un-isolate state. The scheduler rejects isolating
a CPU if it is the only online and un-isolated CPU in the system.
Add the same check for CPU hotplug.

Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
[markivx: forward port to 4.14, fix merge conflicts due to new write-lock]
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>

Change-Id: I16ca44a49dbc7ed385378e08a8634e3c0ac94e03
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>
This commit is contained in:
Pavankumar Kondeti 2017-06-29 16:17:55 +05:30 committed by Gerrit - the friendly Code Review server
parent d0adbc2cd0
commit 5f7b7a9fb8
2 changed files with 12 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
include/linux/cpumask.h
View File

@ -104,6 +104,13 @@ extern struct cpumask __cpu_isolated_mask;
#define num_present_cpus() cpumask_weight(cpu_present_mask)
#define num_active_cpus() cpumask_weight(cpu_active_mask)
#define num_isolated_cpus() cpumask_weight(cpu_isolated_mask)
#define num_online_uniso_cpus() \
({ \
cpumask_t mask; \
\
cpumask_andnot(&mask, cpu_online_mask, cpu_isolated_mask); \
cpumask_weight(&mask); \
})
#define cpu_online(cpu) cpumask_test_cpu((cpu), cpu_online_mask)
#define cpu_possible(cpu) cpumask_test_cpu((cpu), cpu_possible_mask)
#define cpu_present(cpu) cpumask_test_cpu((cpu), cpu_present_mask)
@ -115,6 +122,7 @@ extern struct cpumask __cpu_isolated_mask;
#define num_present_cpus() 1U
#define num_active_cpus() 1U
#define num_isolated_cpus() 0U
#define num_online_uniso_cpus() 1U
#define cpu_online(cpu) ((cpu) == 0)
#define cpu_possible(cpu) ((cpu) == 0)
#define cpu_present(cpu) ((cpu) == 0)

4
kernel/cpu.c
View File

@ -868,6 +868,10 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen,
return -EINVAL;
cpus_write_lock();
if (!tasks_frozen && !cpu_isolated(cpu) && num_online_uniso_cpus() == 1)
return -EBUSY;
if (trace_cpuhp_latency_enabled())
start_time = sched_clock();