Rafael J. Wysocki ad3a999b8b cpufreq/sched: Explicitly synchronize limits_changed flag handling ... [ Upstream commit 79443a7e9d ] The handling of the limits_changed flag in struct sugov_policy needs to be explicitly synchronized to ensure that cpufreq policy limits updates will not be missed in some cases. Without that synchronization it is theoretically possible that the limits_changed update in sugov_should_update_freq() will be reordered with respect to the reads of the policy limits in cpufreq_driver_resolve_freq() and in that case, if the limits_changed update in sugov_limits() clobbers the one in sugov_should_update_freq(), the new policy limits may not take effect for a long time. Likewise, the limits_changed update in sugov_limits() may theoretically get reordered with respect to the updates of the policy limits in cpufreq_set_policy() and if sugov_should_update_freq() runs between them, the policy limits change may be missed. To ensure that the above situations will not take place, add memory barriers preventing the reordering in question from taking place and add READ_ONCE() and WRITE_ONCE() annotations around all of the limits_changed flag updates to prevent the compiler from messing up with that code. Fixes: 600f5badb7 ("cpufreq: schedutil: Don't skip freq update when limits change") Cc: 5.3+ <stable@vger.kernel.org> # 5.3+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Christian Loehle <christian.loehle@arm.com> Link: https://patch.msgid.link/3376719.44csPzL39Z@rjwysocki.net [ bw_min => bw_dl ] Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2025-09-09 18:54:18 +02:00
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autogroup.c
autogroup.h
build_policy.c
build_utility.c
clock.c
completion.c
core_sched.c
core.c	sched: Clarify wake_up_q()'s write to task->wake_q.next	2025-03-28 21:58:51 +01:00
cpuacct.c
cpudeadline.c
cpudeadline.h
cpufreq_schedutil.c	cpufreq/sched: Explicitly synchronize limits_changed flag handling	2025-09-09 18:54:18 +02:00
cpufreq.c
cpupri.c	sched/rt: Fix live lock between select_fallback_rq() and RT push	2023-10-06 14:57:02 +02:00
cpupri.h
cputime.c	sched/cputime: Fix mul_u64_u64_div_u64() precision for cputime	2024-08-14 13:52:50 +02:00
deadline.c	sched/deadline: Use online cpus for validating runtime	2025-04-10 14:33:39 +02:00
debug.c
fair.c	sched/fair: Bump sd->max_newidle_lb_cost when newidle balance fails	2025-08-28 16:25:56 +02:00
features.h
idle.c	kernel/sched: Modify initial boot task idle setup	2023-10-06 14:57:02 +02:00
isolation.c	sched/isolation: Fix boot crash when maxcpus < first housekeeping CPU	2024-06-12 11:03:00 +02:00
loadavg.c	sched: Change nr_uninterruptible type to unsigned long	2025-07-24 08:51:54 +02:00
Makefile
membarrier.c	sched/membarrier: reduce the ability to hammer on sys_membarrier	2024-02-23 09:12:52 +01:00
pelt.c
pelt.h
psi.c	sched: psi: fix bogus pressure spikes from aggregation race	2024-10-17 15:22:06 +02:00
rt.c	sched/rt: sysctl_sched_rr_timeslice show default timeslice after reset	2024-03-01 13:26:24 +01:00
sched-pelt.h
sched.h	sched: Change nr_uninterruptible type to unsigned long	2025-07-24 08:51:54 +02:00
smp.h
stats.c	profiling: remove profile=sleep support	2024-08-14 13:52:50 +02:00
stats.h	sched/psi: Use task->psi_flags to clear in CPU migration	2025-02-21 13:48:54 +01:00
stop_task.c
swait.c
topology.c	sched/fair: Allow disabling sched_balance_newidle with sched_relax_domain_level	2024-06-12 11:03:33 +02:00
wait_bit.c
wait.c