android_kernel_motorola_sm6375/kernel/sched
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Vincent Guittot 6aae92ed2c sched/fair: handle case of task_h_load() returning 0
commit 01cfcde9c26d8555f0e6e9aea9d6049f87683998 upstream.

task_h_load() can return 0 in some situations like running stress-ng
mmapfork, which forks thousands of threads, in a sched group on a 224 cores
system. The load balance doesn't handle this correctly because
env->imbalance never decreases and it will stop pulling tasks only after
reaching loop_max, which can be equal to the number of running tasks of
the cfs. Make sure that imbalance will be decreased by at least 1.

misfit task is the other feature that doesn't handle correctly such
situation although it's probably more difficult to face the problem
because of the smaller number of CPUs and running tasks on heterogenous
system.

We can't simply ensure that task_h_load() returns at least one because it
would imply to handle underflow in other places.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: <stable@vger.kernel.org> # v4.4+
Link: https://lkml.kernel.org/r/20200710152426.16981-1-vincent.guittot@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-22 09:33:16 +02:00
..
autogroup.c
autogroup.h
clock.c
completion.c
core.c sched: Fix unreliable rseq cpu_id for new tasks 2020-07-22 09:33:16 +02:00
cpuacct.c
cpudeadline.c
cpudeadline.h
cpufreq.c cpufreq: Avoid leaving stale IRQ work items during CPU offline 2019-12-31 16:46:06 +01:00
cpufreq_schedutil.c cpufreq: Avoid leaving stale IRQ work items during CPU offline 2019-12-31 16:46:06 +01:00
cpupri.c
cpupri.h
cputime.c sched/vtime: Fix guest/system mis-accounting on task switch 2019-10-09 12:38:03 +02:00
deadline.c sched/deadline: Initialize ->dl_boosted 2020-06-30 15:37:02 -04:00
debug.c sched/debug: Make sd->flags sysctl read-only 2020-07-09 09:37:50 +02:00
fair.c sched/fair: handle case of task_h_load() returning 0 2020-07-22 09:33:16 +02:00
features.h
idle.c sched/core: Further clarify sched_class::set_next_task() 2020-01-26 10:01:03 +01:00
isolation.c sched/isolation: Prefer housekeeping CPU in local node 2019-07-25 15:51:55 +02:00
loadavg.c timers/nohz: Update NOHZ load in remote tick 2020-03-05 16:43:36 +01:00
Makefile
membarrier.c membarrier: Fix RCU locking bug caused by faulty merge 2019-10-01 21:27:50 +02:00
pelt.c
pelt.h
psi.c sched/psi: Fix OOB write when writing 0 bytes to PSI files 2020-02-28 17:22:21 +01:00
rt.c sched: Defend cfs and rt bandwidth quota against overflow 2020-06-22 09:31:07 +02:00
sched-pelt.h
sched.h sched: Defend cfs and rt bandwidth quota against overflow 2020-06-22 09:31:07 +02:00
stats.c
stats.h sched/stats: Fix unlikely() use of sched_info_on() 2019-07-25 15:51:55 +02:00
stop_task.c sched/core: Further clarify sched_class::set_next_task() 2020-01-26 10:01:03 +01:00
swait.c
topology.c sched/topology: Assert non-NUMA topology masks don't (partially) overlap 2020-02-24 08:36:52 +01:00
wait.c
wait_bit.c