diff options
| author | Zhongqiu Han <zhongqiu.han@oss.qualcomm.com> | 2026-06-16 23:47:33 +0800 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2026-06-17 20:07:47 +0200 |
| commit | 9ef450ca74e43dacf9a2a15db7a851052c78dcf0 (patch) | |
| tree | 5ba964697562876124f0e3c80f5772a5eec97bd2 /mm/tests/git@git.tavy.me:linux.git | |
| parent | 5504ce0317f777dcf102751c3e518284226fc2e1 (diff) | |
cpufreq: schedutil: Fix uncleared need_freq_update on the .adjust_perf() path
The need_freq_update flag makes sugov_should_update_freq() return true
regardless of the rate_limit_us throttling, and is cleared in
sugov_update_next_freq(). sugov_update_single_freq() and
sugov_update_shared() go through that helper, so the flag does not
persist there.
However, sugov_update_single_perf(), used by drivers implementing the
.adjust_perf() callback (e.g. intel_pstate or amd-pstate in passive
mode) calls cpufreq_driver_adjust_perf() directly and never goes through
sugov_update_next_freq(), so the need_freq_update flag is not cleared in
that path.
Before commit 75da043d8f88 ("cpufreq/sched: Set need_freq_update in
ignore_dl_rate_limit()"), this was effectively harmless because
sugov_should_update_freq() still honored the rate limit even when
need_freq_update was set. After that change, the flag forces
sugov_should_update_freq() to always return true, so once set, it
stays effective indefinitely on the .adjust_perf() path.
As a result, cpufreq_driver_adjust_perf() gets called on every scheduler
utilization update (with the runqueue lock held) rather than being
throttled by rate_limit_us, even if the driver itself may skip redundant
hardware updates.
Clear need_freq_update at the end of the adjust_perf path as well.
Fixes: 75da043d8f88 ("cpufreq/sched: Set need_freq_update in ignore_dl_rate_limit()")
Signed-off-by: Zhongqiu Han <zhongqiu.han@oss.qualcomm.com>
Reviewed-by: Hongyan Xia <hongyan.xia@transsion.com>
Reviewed-by: Christian Loehle <christian.loehle@arm.com>
Cc: All applicable <stable@vger.kernel.org>
[ rjw: Subject and changelog edits ]
Link: https://patch.msgid.link/20260616154733.2405236-1-zhongqiu.han@oss.qualcomm.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'mm/tests/git@git.tavy.me:linux.git')
0 files changed, 0 insertions, 0 deletions
