linux/kernel/sched
Barry Song c8987ae5af sched/fair: Optimize test_idle_cores() for !SMT
update_idle_core() is only done for the case of sched_smt_present.
but test_idle_cores() is done for all machines even those without
SMT.

This can contribute to up 8%+ hackbench performance loss on a
machine like kunpeng 920 which has no SMT. This patch removes the
redundant test_idle_cores() for !SMT machines.

Hackbench is ran with -g {2..14}, for each g it is ran 10 times to get
an average.

  $ numactl -N 0 hackbench -p -T -l 20000 -g $1

The below is the result of hackbench w/ and w/o this patch:

  g=    2      4     6       8      10     12      14
  w/o: 1.8151 3.8499 5.5142 7.2491 9.0340 10.7345 12.0929
  w/ : 1.8428 3.7436 5.4501 6.9522 8.2882  9.9535 11.3367
			    +4.1%  +8.3%  +7.3%   +6.3%

Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Link: https://lkml.kernel.org/r/20210320221432.924-1-song.bao.hua@hisilicon.com
2021-03-23 16:01:59 +01:00
..
autogroup.c sched/autogroup: Make autogroup_path() always available 2019-06-24 19:23:40 +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: Fix various typos 2021-03-22 00:11:52 +01:00
completion.c completion: Use lockdep_assert_RT_in_threaded_ctx() in complete_all() 2020-03-23 18:40:25 +01:00
core.c sched: Fix various typos 2021-03-22 00:11:52 +01:00
cpuacct.c sched: Fix various typos 2021-03-22 00:11:52 +01:00
cpudeadline.c sched,rt: Use the full cpumask for balancing 2020-11-10 18:39:00 +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: Fix various typos 2021-03-22 00:11:52 +01:00
cpufreq.c cpufreq: Avoid leaving stale IRQ work items during CPU offline 2019-12-12 17:59:43 +01:00
cpupri.c sched: Fix various typos 2021-03-22 00:11:52 +01:00
cpupri.h sched/cpupri: Add CPUPRI_HIGHER 2020-10-29 11:00:30 +01:00
cputime.c sched: Fix various typos 2021-03-22 00:11:52 +01:00
deadline.c sched: Fix various typos 2021-03-22 00:11:52 +01:00
debug.c sched: Fix various typos 2021-03-22 00:11:52 +01:00
fair.c sched/fair: Optimize test_idle_cores() for !SMT 2021-03-23 16:01:59 +01:00
features.h sched: Fix various typos 2021-03-22 00:11:52 +01:00
idle.c sched: Fix various typos 2021-03-22 00:11:52 +01:00
isolation.c isolcpus: Affine unbound kernel threads to housekeeping cpus 2020-06-15 14:10:03 +02:00
loadavg.c sched: Fix various typos 2021-03-22 00:11:52 +01:00
Makefile kcsan: Improve various small stylistic details 2019-11-20 10:47:23 +01:00
membarrier.c sched/membarrier: fix missing local execution of ipi_sync_rq_state() 2021-03-06 12:40:21 +01:00
pelt.c sched: Fix various typos 2021-03-22 00:11:52 +01:00
pelt.h sched: Fix various typos 2021-03-22 00:11:52 +01:00
psi.c psi: Reduce calls to sched_clock() in psi 2021-03-23 16:01:58 +01:00
rt.c sched: Fix various typos 2021-03-22 00:11:52 +01:00
sched-pelt.h sched/fair: Fix "runnable_avg_yN_inv" not used warnings 2019-06-17 12:15:58 +02:00
sched.h sched: Fix various typos 2021-03-22 00:11:52 +01:00
smp.h sched/headers: Split out open-coded prototypes into kernel/sched/smp.h 2020-05-28 11:03:20 +02:00
stats.c sched: Fix various typos 2021-03-22 00:11:52 +01:00
stats.h psi: Optimize task switch inside shared cgroups 2021-03-06 12:40:23 +01:00
stop_task.c sched: Remove select_task_rq()'s sd_flag parameter 2020-11-10 18:39:06 +01:00
swait.c sched/swait: Prepare usage in completions 2020-03-21 16:00:23 +01:00
topology.c sched: Fix various typos 2021-03-22 00:11:52 +01:00
wait_bit.c sched/wait: fix ___wait_var_event(exclusive) 2019-12-17 13:32:50 +01:00
wait.c sched/wait: Add add_wait_queue_priority() 2020-11-15 09:49:09 -05:00