pm: cpupower: Fix the snapshot-order of tsc,mperf, clock in mperf_stop()
[ Upstream commit cda7ac8ce7de84cf32a3871ba5f318aa3b79381e ] In the function mperf_start(), mperf_monitor snapshots the time, tsc and finally the aperf,mperf MSRs. However, this order of snapshotting in is reversed in mperf_stop(). As a result, the C0 residency (which is computed as delta_mperf * 100 / delta_tsc) is under-reported on CPUs that is 100% busy. Fix this by snapshotting time, tsc and then aperf,mperf in mperf_stop() in the same order as in mperf_start(). Link: https://lore.kernel.org/r/20250612122355.19629-2-gautham.shenoy@amd.com Signed-off-by:Gautham R. Shenoy <gautham.shenoy@amd.com> Signed-off-by:
Shuah Khan <skhan@linuxfoundation.org> Signed-off-by:
Sasha Levin <sashal@kernel.org>
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