Tejun Heo 89909296a5 sched_ext: Don't use double locking to migrate tasks across CPUs ... consume_remote_task() and dispatch_to_local_dsq() use move_task_to_local_dsq() to migrate the task to the target CPU. Currently, move_task_to_local_dsq() expects the caller to lock both the source and destination rq's. While this may save a few lock operations while the rq's are not contended, under contention, the double locking can exacerbate the situation significantly (refer to the linked message below). Update the migration path so that double locking is not used. move_task_to_local_dsq() now expects the caller to be locking the source rq, drops it and then acquires the destination rq lock. Code is simpler this way and, on a 2-way NUMA machine w/ Xeon Gold 6138, 'hackbench 100 thread 5000` shows ~3% improvement with scx_simple. Signed-off-by: Tejun Heo <tj@kernel.org> Suggested-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20240806082716.GP37996@noisy.programming.kicks-ass.net Acked-by: David Vernet <void@manifault.com>		2024-08-13 09:08:50 -10:00
..
autogroup.c	scheduler: Remove the now superfluous sentinel elements from ctl_table array	2024-04-24 09:43:54 +02:00
autogroup.h	sched/headers: Add header guard to kernel/sched/stats.h and kernel/sched/autogroup.h	2022-02-23 08:22:00 +01:00
build_policy.c	sched_ext: Disallow loading BPF scheduler if isolcpus= domain isolation is in effect	2024-07-08 09:30:13 -10:00
build_utility.c	sched/headers: Remove duplicate header inclusions	2023-10-03 21:27:55 +02:00
clock.c	sched: Fix spelling in comments	2024-05-27 17:00:21 +02:00
completion.c	sched: add a few helpers to wake up tasks on the current cpu	2023-07-17 16:08:08 -07:00
core_sched.c	sched: Fix spelling in comments	2024-05-27 17:00:21 +02:00
core.c	sched_ext: Make task_can_run_on_remote_rq() use common task_allowed_on_cpu()	2024-08-06 09:40:11 -10:00
cpuacct.c	Merge branch 'sched/fast-headers' into sched/core	2022-03-15 09:05:05 +01:00
cpudeadline.c	sched/topology: Consolidate and clean up access to a CPU's max compute capacity	2023-10-09 12:59:48 +02:00
cpudeadline.h
cpufreq_schedutil.c	sched_ext: Add cpuperf support	2024-06-21 12:37:22 -10:00
cpufreq.c	sched/headers: Introduce kernel/sched/build_utility.c and build multiple .c files there	2022-02-23 10:58:33 +01:00
cpupri.c	sched/rt: Fix live lock between select_fallback_rq() and RT push	2023-09-28 22:58:13 +02:00
cpupri.h	sched/cpupri: Add CPUPRI_HIGHER	2020-10-29 11:00:30 +01:00
cputime.c	sched/cputime: Fix mul_u64_u64_div_u64() precision for cputime	2024-07-29 12:22:32 +02:00
deadline.c	sched/rt: Remove default bandwidth control	2024-07-29 12:22:37 +02:00
debug.c	Merge branch 'sched/core' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into for-6.12	2024-08-04 07:36:54 -10:00
ext.c	sched_ext: Don't use double locking to migrate tasks across CPUs	2024-08-13 09:08:50 -10:00
ext.h	sched, sched_ext: Move some declarations from kernel/sched/ext.h to sched.h	2024-07-08 09:39:48 -10:00
fair.c	Merge branch 'sched/core' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into for-6.12	2024-08-04 07:36:54 -10:00
features.h	sched: remove HZ_BW feature hedge	2024-07-29 12:22:34 +02:00
idle.c	Merge branch 'sched/core' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into for-6.12	2024-08-04 07:36:54 -10:00
isolation.c	sched/isolation: Fix boot crash when maxcpus < first housekeeping CPU	2024-04-28 10:08:21 +02:00
loadavg.c	sched: Fix spelling in comments	2024-05-27 17:00:21 +02:00
Makefile	sched/headers: Introduce kernel/sched/build_policy.c and build multiple .c files there	2022-02-23 10:58:33 +01:00
membarrier.c	RISC-V Patches for the 6.9 Merge Window	2024-03-22 10:41:13 -07:00
pelt.c	sched: Fix spelling in comments	2024-05-27 17:00:21 +02:00
pelt.h	sched/cpufreq: Rename arch_update_thermal_pressure() => arch_update_hw_pressure()	2024-04-24 12:08:01 +02:00
psi.c	Merge branch 'sched/urgent' into sched/core, to pick up fixes and refresh the branch	2024-07-11 10:42:33 +02:00
rt.c	sched/rt: Remove default bandwidth control	2024-07-29 12:22:37 +02:00
sched-pelt.h	sched/fair: Fix "runnable_avg_yN_inv" not used warnings	2019-06-17 12:15:58 +02:00
sched.h	sched_ext: Make task_can_run_on_remote_rq() use common task_allowed_on_cpu()	2024-08-06 09:40:11 -10:00
smp.h	sched, smp: Trace smp callback causing an IPI	2023-03-24 11:01:29 +01:00
stats.c	sched/debug: Increase SCHEDSTAT_VERSION to 16	2024-03-12 11:03:40 +01:00
stats.h	Merge branch 'sched/urgent' into sched/core, to pick up fixes and refresh the branch	2024-07-11 10:42:33 +02:00
stop_task.c	sched: Unify runtime accounting across classes	2023-11-15 09:57:48 +01:00
swait.c	sched: add a few helpers to wake up tasks on the current cpu	2023-07-17 16:08:08 -07:00
syscalls.c	sched_ext: Allow BPF schedulers to disallow specific tasks from joining SCHED_EXT	2024-06-18 10:09:18 -10:00
topology.c	sched/fair: Fair server interface	2024-07-29 12:22:36 +02:00
wait_bit.c	sched: Fix spelling in comments	2024-05-27 17:00:21 +02:00
wait.c	sched: remove wait bookmarks	2023-10-18 14:34:18 -07:00