Vincent Guittot 57b2f3632b sched/pelt: Relax the sync of util_sum with util_avg ... [ Upstream commit 98b0d890220d45418cfbc5157b3382e6da5a12ab ] Rick reported performance regressions in bugzilla because of cpu frequency being lower than before: https://bugzilla.kernel.org/show_bug.cgi?id=215045 He bisected the problem to: commit 1c35b07e6d39 ("sched/fair: Ensure _sum and _avg values stay consistent") This commit forces util_sum to be synced with the new util_avg after removing the contribution of a task and before the next periodic sync. By doing so util_sum is rounded to its lower bound and might lost up to LOAD_AVG_MAX-1 of accumulated contribution which has not yet been reflected in util_avg. Instead of always setting util_sum to the low bound of util_avg, which can significantly lower the utilization of root cfs_rq after propagating the change down into the hierarchy, we revert the change of util_sum and propagate the difference. In addition, we also check that cfs's util_sum always stays above the lower bound for a given util_avg as it has been observed that sched_entity's util_sum is sometimes above cfs one. Fixes: 1c35b07e6d39 ("sched/fair: Ensure _sum and _avg values stay consistent") Reported-by: Rick Yiu <rickyiu@google.com> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Tested-by: Sachin Sant <sachinp@linux.ibm.com> Link: https://lkml.kernel.org/r/20220111134659.24961-2-vincent.guittot@linaro.org Signed-off-by: Sasha Levin <sashal@kernel.org>		2022-02-01 17:25:45 +01:00
..
bpf	bpf: Guard against accessing NULL pt_regs in bpf_get_task_stack()	2022-02-01 17:25:38 +01:00
cgroup	cgroup: Fix rootcg cpu.stat guest double counting	2021-11-18 14:04:13 +01:00
configs
debug	kgdb: fix to kill breakpoints on initmem after boot	2021-03-04 11:38:46 +01:00
dma	dma/pool: create dma atomic pool only if dma zone has managed pages	2022-01-27 10:53:44 +01:00
entry	KVM: rseq: Update rseq when processing NOTIFY_RESUME on xfer to KVM guest	2021-10-06 15:55:49 +02:00
events	perf: Fix perf_event_read_local() time	2022-02-01 17:25:45 +01:00
gcov	gcov: re-fix clang-11+ support	2021-04-14 08:41:58 +02:00
irq	genirq/timings: Fix error return code in irq_timings_test_irqs()	2021-09-15 09:50:29 +02:00
kcsan	kcsan: Fix debugfs initcall return type	2021-05-26 12:06:54 +02:00
livepatch
locking	kernel: delete repeated words in comments	2022-02-01 17:25:45 +01:00
power	PM: wakeup: simplify the output logic of pm_show_wakelocks()	2022-02-01 17:25:39 +01:00
printk	printk/console: Allow to disable console output by using console="" or console=null	2021-11-12 14:58:33 +01:00
rcu	rcu: Tighten rcu_advance_cbs_nowake() checks	2022-01-29 10:26:11 +01:00
sched	sched/pelt: Relax the sync of util_sum with util_avg	2022-02-01 17:25:45 +01:00
time	clocksource: Avoid accidental unstable marking of clocksources	2022-01-27 10:54:06 +01:00
trace	tracing: Don't inc err_log entry count if entry allocation fails	2022-02-01 17:25:39 +01:00
.gitignore	kbuild: update config_data.gz only when the content of .config is changed	2021-05-11 14:47:37 +02:00
acct.c
async.c
audit_fsnotify.c	fsnotify: generalize handle_inode_event()	2020-12-30 11:54:18 +01:00
audit_tree.c	audit: move put_tree() to avoid trim_trees refcount underflow and UAF	2021-09-03 10:09:31 +02:00
audit_watch.c	fsnotify: generalize handle_inode_event()	2020-12-30 11:54:18 +01:00
audit.c	audit: ensure userspace is penalized the same as the kernel when under pressure	2022-01-27 10:54:16 +01:00
audit.h
auditfilter.c
auditsc.c	audit: fix possible null-pointer dereference in audit_filter_rules	2021-10-27 09:56:52 +02:00
backtracetest.c
bounds.c
capability.c
compat.c
configs.c
context_tracking.c
cpu_pm.c	PM: cpu: Make notifier chain use a raw_spinlock_t	2021-09-15 09:50:40 +02:00
cpu.c	sched/scs: Reset task stack state in bringup_cpu()	2021-12-01 09:19:08 +01:00
crash_core.c	crash_core, vmcoreinfo: append 'SECTION_SIZE_BITS' to vmcoreinfo	2021-06-23 14:42:52 +02:00
crash_dump.c
cred.c	Revert "Add a reference to ucounts for each cred"	2021-09-08 08:49:00 +02:00
delayacct.c
dma.c
exec_domain.c
exit.c	kernel/io_uring: cancel io_uring before task works	2021-01-30 13:55:18 +01:00
extable.c
fail_function.c
fork.c	posix-cpu-timers: Clear task::posix_cputimers_work in copy_process()	2021-11-18 14:04:29 +01:00
freezer.c	Revert "kernel: freezer should treat PF_IO_WORKER like PF_KTHREAD for freezing"	2021-04-07 15:00:14 +02:00
futex.c	mm, futex: fix shared futex pgoff on shmem huge page	2021-06-30 08:47:29 -04:00
gen_kheaders.sh
groups.c
hung_task.c
iomem.c
irq_work.c
jump_label.c	jump_label: Fix jump_label_text_reserved() vs __init	2021-07-20 16:05:58 +02:00
kallsyms.c
kcmp.c	exec: Transform exec_update_mutex into a rw_semaphore	2021-01-09 13:46:24 +01:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c
kexec_core.c	kernel: kexec: remove the lock operation of system_transition_mutex	2021-02-03 23:28:37 +01:00
kexec_elf.c
kexec_file.c	kernel: kexec_file: fix error return code of kexec_calculate_store_digests()	2021-05-19 10:13:09 +02:00
kexec_internal.h
kexec.c
kheaders.c
kmod.c
kprobes.c	kprobes: Limit max data_size of the kretprobe instances	2021-12-08 09:03:20 +01:00
ksysfs.c
kthread.c	kthread: Fix PF_KTHREAD vs to_kthread() race	2021-09-03 10:09:31 +02:00
latencytop.c
Makefile	kbuild: update config_data.gz only when the content of .config is changed	2021-05-11 14:47:37 +02:00
module_signature.c	module: harden ELF info handling	2021-03-25 09:04:11 +01:00
module_signing.c	module: harden ELF info handling	2021-03-25 09:04:11 +01:00
module-internal.h
module.c	module: limit enabling module.sig_enforce	2021-06-30 08:47:15 -04:00
notifier.c
nsproxy.c
padata.c
panic.c
params.c
pid_namespace.c	memcg: enable accounting for pids in nested pid namespaces	2021-09-18 13:40:36 +02:00
pid.c	exec: Transform exec_update_mutex into a rw_semaphore	2021-01-09 13:46:24 +01:00
profile.c	profiling: fix shift-out-of-bounds bugs	2021-09-26 14:08:58 +02:00
ptrace.c	ptrace: make ptrace() fail if the tracee changed its pid unexpectedly	2021-05-26 12:06:49 +02:00
range.c
reboot.c
regset.c
relay.c
resource.c	kernel/resource: make walk_mem_res() find all busy IORESOURCE_MEM resources	2021-05-19 10:13:09 +02:00
rseq.c	KVM: rseq: Update rseq when processing NOTIFY_RESUME on xfer to KVM guest	2021-10-06 15:55:49 +02:00
scftorture.c
scs.c
seccomp.c	seccomp: Fix setting loaded filter count during TSYNC	2021-08-18 08:59:06 +02:00
signal.c	signal: Remove the bogus sigkill_pending in ptrace_stop	2021-11-18 14:03:47 +01:00
smp.c	smp: Fix smp_call_function_single_async prototype	2021-05-14 09:50:46 +02:00
smpboot.c	sched/core: Initialize the idle task with preemption disabled	2021-07-14 16:55:50 +02:00
smpboot.h
softirq.c
stackleak.c
stacktrace.c
static_call.c	static_call: Fix unused variable warn w/o MODULE	2021-09-08 08:49:00 +02:00
stop_machine.c
sys_ni.c
sys.c	prctl: allow to setup brk for et_dyn executables	2021-09-26 14:08:57 +02:00
sysctl-test.c
sysctl.c	bpf: Add kconfig knob for disabling unpriv bpf by default	2022-01-05 12:40:34 +01:00
task_work.c
taskstats.c
test_kprobes.c
torture.c
tracepoint.c	tracepoint: Use rcu get state and cond sync for static call updates	2021-09-03 10:09:30 +02:00
tsacct.c	taskstats: Cleanup the use of task->exit_code	2022-01-27 10:54:33 +01:00
ucount.c	Revert "Add a reference to ucounts for each cred"	2021-09-08 08:49:00 +02:00
uid16.c
uid16.h
umh.c
up.c	smp: Fix smp_call_function_single_async prototype	2021-05-14 09:50:46 +02:00
user_namespace.c	Revert "Add a reference to ucounts for each cred"	2021-09-08 08:49:00 +02:00
user-return-notifier.c
user.c
usermode_driver.c	bpf: Fix umd memory leak in copy_process()	2021-03-30 14:32:03 +02:00
utsname_sysctl.c
utsname.c
watch_queue.c
watchdog_hld.c
watchdog.c	watchdog: fix barriers when printing backtraces from all CPUs	2021-05-19 10:13:00 +02:00
workqueue_internal.h
workqueue.c	workqueue: Fix unbind_workers() VS wq_worker_running() race	2022-01-16 09:14:22 +01:00