This is a note to let you know that I've just added the patch titled
amd-pstate: Set min_perf to nominal_perf for active mode performance gov
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
amd-pstate-set-min_perf-to-nominal_perf-for-active-m.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 3eb5e0305011570ce50f426ab769f7e7eee99d94
Author: Gautham R. Shenoy <gautham.shenoy@xxxxxxx>
Date: Mon Oct 21 15:48:35 2024 +0530
amd-pstate: Set min_perf to nominal_perf for active mode performance gov
[ Upstream commit 0c411b39e4f4ce8861301fa201cb4f817751311e ]
The amd-pstate driver sets CPPC_REQ.min_perf to CPPC_REQ.max_perf when
in active mode with performance governor. Typically CPPC_REQ.max_perf
is set to CPPC.highest_perf. This causes frequency throttling on
power-limited platforms which causes performance regressions on
certain classes of workloads.
Hence, set the CPPC_REQ.min_perf to the CPPC.nominal_perf or
CPPC_REQ.max_perf, whichever is lower of the two.
Fixes: ffa5096a7c33 ("cpufreq: amd-pstate: implement Pstate EPP support for the AMD processors")
Signed-off-by: Gautham R. Shenoy <gautham.shenoy@xxxxxxx>
Reviewed-by: Mario Limonciello <mario.limonciello@xxxxxxx>
Link: https://lore.kernel.org/r/20241021101836.9047-2-gautham.shenoy@xxxxxxx
Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 8c16d67b98bfe..cdead37d0823a 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -1383,7 +1383,7 @@ static void amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
value = READ_ONCE(cpudata->cppc_req_cached);
if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
- min_perf = max_perf;
+ min_perf = min(cpudata->nominal_perf, max_perf);
/* Initial min/max values for CPPC Performance Controls Register */
value &= ~AMD_CPPC_MIN_PERF(~0L);
