linux_dsm_epyc7002/kernel/sched
Hailong Liu f3d133ee0a sched/rt: Restore rt_runtime after disabling RT_RUNTIME_SHARE
NO_RT_RUNTIME_SHARE feature is used to prevent a CPU borrow enough
runtime with a spin-rt-task.

However, if RT_RUNTIME_SHARE feature is enabled and rt_rq has borrowd
enough rt_runtime at the beginning, rt_runtime can't be restored to
its initial bandwidth rt_runtime after we disable RT_RUNTIME_SHARE.

E.g. on my PC with 4 cores, procedure to reproduce:
1) Make sure  RT_RUNTIME_SHARE is enabled
 cat /sys/kernel/debug/sched_features
  GENTLE_FAIR_SLEEPERS START_DEBIT NO_NEXT_BUDDY LAST_BUDDY
  CACHE_HOT_BUDDY WAKEUP_PREEMPTION NO_HRTICK NO_DOUBLE_TICK
  LB_BIAS NONTASK_CAPACITY TTWU_QUEUE NO_SIS_AVG_CPU SIS_PROP
  NO_WARN_DOUBLE_CLOCK RT_PUSH_IPI RT_RUNTIME_SHARE NO_LB_MIN
  ATTACH_AGE_LOAD WA_IDLE WA_WEIGHT WA_BIAS
2) Start a spin-rt-task
 ./loop_rr &
3) set affinity to the last cpu
 taskset -p 8 $pid_of_loop_rr
4) Observe that last cpu have borrowed enough runtime.
 cat /proc/sched_debug | grep rt_runtime
  .rt_runtime                    : 950.000000
  .rt_runtime                    : 900.000000
  .rt_runtime                    : 950.000000
  .rt_runtime                    : 1000.000000
5) Disable RT_RUNTIME_SHARE
 echo NO_RT_RUNTIME_SHARE > /sys/kernel/debug/sched_features
6) Observe that rt_runtime can not been restored
 cat /proc/sched_debug | grep rt_runtime
  .rt_runtime                    : 950.000000
  .rt_runtime                    : 900.000000
  .rt_runtime                    : 950.000000
  .rt_runtime                    : 1000.000000

This patch help to restore rt_runtime after we disable
RT_RUNTIME_SHARE.

Signed-off-by: Hailong Liu <liu.hailong6@zte.com.cn>
Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: zhong.weidong@zte.com.cn
Link: http://lkml.kernel.org/r/1531874815-39357-1-git-send-email-liu.hailong6@zte.com.cn
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25 11:29:08 +02:00
..
autogroup.c sched/autogroup: Fix possible Spectre-v1 indexing for sched_prio_to_weight[] 2018-05-05 08:34:42 +02:00
autogroup.h sched/headers: Simplify and clean up header usage in the scheduler 2018-03-04 12:39:29 +01:00
clock.c sched/headers: Simplify and clean up header usage in the scheduler 2018-03-04 12:39:29 +01:00
completion.c sched/completions: Use bool in try_wait_for_completion() 2018-03-09 08:00:18 +01:00
core.c kthread, sched/core: Fix kthread_parkme() (again...) 2018-07-03 09:17:30 +02:00
cpuacct.c sched/headers: Simplify and clean up header usage in the scheduler 2018-03-04 12:39:29 +01:00
cpudeadline.c sched/headers: Simplify and clean up header usage in the scheduler 2018-03-04 12:39:29 +01:00
cpudeadline.h sched/headers: Simplify and clean up header usage in the scheduler 2018-03-04 12:39:29 +01:00
cpufreq_schedutil.c sched/rt: Fix call to cpufreq_update_util() 2018-07-03 09:17:28 +02:00
cpufreq.c sched/headers: Simplify and clean up header usage in the scheduler 2018-03-04 12:39:29 +01:00
cpupri.c sched/headers: Simplify and clean up header usage in the scheduler 2018-03-04 12:39:29 +01:00
cpupri.h sched/headers: Simplify and clean up header usage in the scheduler 2018-03-04 12:39:29 +01:00
cputime.c sched/headers: Simplify and clean up header usage in the scheduler 2018-03-04 12:39:29 +01:00
deadline.c sched/deadline: Update rq_clock of later_rq when pushing a task 2018-07-25 11:29:08 +02:00
debug.c proc: introduce proc_create_seq{,_data} 2018-05-16 07:23:35 +02:00
fair.c sched/util_est: Fix util_est_dequeue() for throttled cfs_rq 2018-07-03 09:17:30 +02:00
features.h sched/fair: Update util_est only on util_avg updates 2018-03-20 08:11:09 +01:00
idle.c sched: idle: Select idle state before stopping the tick 2018-04-09 11:54:07 +02:00
isolation.c sched/headers: Simplify and clean up header usage in the scheduler 2018-03-04 12:39:29 +01:00
loadavg.c sched/headers: Simplify and clean up header usage in the scheduler 2018-03-04 12:39:29 +01:00
Makefile sched/idle: Merge kernel/sched/idle.c and kernel/sched/idle_task.c 2018-03-04 12:39:33 +01:00
membarrier.c sched/headers: Simplify and clean up header usage in the scheduler 2018-03-04 12:39:29 +01:00
rt.c sched/rt: Restore rt_runtime after disabling RT_RUNTIME_SHARE 2018-07-25 11:29:08 +02:00
sched-pelt.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
sched.h sched/fair: Fix bandwidth timer clock drift condition 2018-07-03 09:17:29 +02:00
stats.c proc: introduce proc_create_seq{,_data} 2018-05-16 07:23:35 +02:00
stats.h sched: Clean up and harmonize the coding style of the scheduler code base 2018-03-03 15:50:21 +01:00
stop_task.c sched: Clean up and harmonize the coding style of the scheduler code base 2018-03-03 15:50:21 +01:00
swait.c sched/headers: Simplify and clean up header usage in the scheduler 2018-03-04 12:39:29 +01:00
topology.c sched/topology: Check variable group before dereferencing it 2018-07-25 11:25:07 +02:00
wait_bit.c sched/wait: Improve __var_waitqueue() code generation 2018-03-20 08:23:25 +01:00
wait.c sched/headers: Simplify and clean up header usage in the scheduler 2018-03-04 12:39:29 +01:00