kernel_optimize_test/kernel/sched
Valentin Schneider c200191d4c sched/topology: Propagate SD_ASYM_CPUCAPACITY upwards
We currently set this flag *only* on domains whose topology level exactly
match the level where we detect asymmetry (as returned by
asym_cpu_capacity_level()). This is rather problematic.

Say there are two clusters in the system, one with a lone big CPU and the
other with a mix of big and LITTLE CPUs (as is allowed by DynamIQ):

  DIE [                ]
  MC  [             ][ ]
       0   1   2   3  4
       L   L   B   B  B

asym_cpu_capacity_level() will figure out that the MC level is the one
where all CPUs can see a CPU of max capacity, and we will thus set
SD_ASYM_CPUCAPACITY at MC level for all CPUs.

That lone big CPU will degenerate its MC domain, since it would be alone in
there, and will end up with just a DIE domain. Since the flag was only set
at MC, this CPU ends up not seeing any SD with the flag set, which is
broken.

Rather than clearing dflags at every topology level, clear it before
entering the topology level loop. This will properly propagate upwards
flags that are set starting from a certain level.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Quentin Perret <qperret@google.com>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: https://lore.kernel.org/r/20200817113003.20802-11-valentin.schneider@arm.com
2020-08-19 10:49:49 +02:00
..
autogroup.c
autogroup.h
clock.c
completion.c completion: Use lockdep_assert_RT_in_threaded_ctx() in complete_all() 2020-03-23 18:40:25 +01:00
core.c Two fixes: fix a new tracepoint's output value, and fix the formatting of show-state syslog printouts. 2020-08-15 10:36:40 -07:00
cpuacct.c sched/cpuacct: Fix charge cpuacct.usage_sys 2020-05-19 20:34:14 +02:00
cpudeadline.c sched/deadline: Implement fallback mechanism for !fit case 2020-06-15 14:10:05 +02:00
cpudeadline.h
cpufreq_schedutil.c Power management updates for 5.9-rc1 2020-08-03 20:28:08 -07:00
cpufreq.c
cpupri.c sched/rt: cpupri_find: Trigger a full search as fallback 2020-03-20 13:06:20 +01:00
cpupri.h sched/rt: Optimize cpupri_find() on non-heterogenous systems 2020-03-06 12:57:27 +01:00
cputime.c sched/cputime: Improve cputime_adjust() 2020-06-15 14:10:00 +02:00
deadline.c Merge branch 'sched/urgent' 2020-07-08 11:38:59 +02:00
debug.c sched/debug: Output SD flag names rather than their values 2020-08-19 10:49:48 +02:00
fair.c Power management updates for 5.9-rc1 2020-08-03 20:28:08 -07:00
features.h
idle.c Merge branch 'sched/urgent' 2020-07-08 11:38:59 +02:00
isolation.c isolcpus: Affine unbound kernel threads to housekeeping cpus 2020-06-15 14:10:03 +02:00
loadavg.c sched: nohz: stop passing around unused "ticks" parameter. 2020-07-22 10:22:04 +02:00
Makefile
membarrier.c
pelt.c sched: Add a tracepoint to track rq->nr_running 2020-07-08 11:39:02 +02:00
pelt.h sched/pelt: Cleanup PELT divider 2020-06-15 14:10:06 +02:00
psi.c sched,psi: Convert to sched_set_fifo_low() 2020-06-15 14:10:25 +02:00
rt.c sched: Remove struct sched_class::next field 2020-06-25 13:45:44 +02:00
sched-pelt.h
sched.h sched: Fix use of count for nr_running tracepoint 2020-08-06 09:36:59 +02:00
smp.h sched/headers: Split out open-coded prototypes into kernel/sched/smp.h 2020-05-28 11:03:20 +02:00
stats.c
stats.h psi: Move PF_MEMSTALL out of task->flags 2020-03-20 13:06:19 +01:00
stop_task.c sched: Remove struct sched_class::next field 2020-06-25 13:45:44 +02:00
swait.c sched/swait: Prepare usage in completions 2020-03-21 16:00:23 +01:00
topology.c sched/topology: Propagate SD_ASYM_CPUCAPACITY upwards 2020-08-19 10:49:49 +02:00
wait_bit.c
wait.c list: add "list_del_init_careful()" to go with "list_empty_careful()" 2020-08-02 20:39:44 -07:00