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| author | Ravi Bangoria <ravi.bangoria@amd.com> | 2026-10-26 04:18:37 +0000 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2026-11-06 09:50:21 +0100 |
| commit | 927f9c5cdadbc4ac6973bcd1690107fcb392612c (patch) | |
| tree | 82dbae4480c2a45fc016de5b200c3c816440eb43 /scripts/Makefile.thinlto | |
| parent | b61c12527223423ab66891b2e8131da0d66537c4 (diff) | |
| download | linux-next-927f9c5cdadbc4ac6973bcd1690107fcb392612c.tar.gz linux-next-927f9c5cdadbc4ac6973bcd1690107fcb392612c.zip | |
perf/amd/ibs: Simplify event state handling with IBS_CAPS_DIS
The IBS_{FETCH|OP}_CTL2[Dis] bit allows IBS sampling to be stopped without
a RMW of IBS_{FETCH,OP}_CTL. Systems providing this bit therefore do not
require the IBS_STARTED and IBS_STOPPED states used to coordinate control
MSR updates with late NMIs.
Add a separate stop path for these systems. Preserve the Val bit while
disabling the event so that a delayed NMI can be identified and consumed,
and wait briefly for such an NMI before restarting the event.
Leave the existing handling unchanged on systems without IBS_CAPS_DIS.
Closes: https://lore.kernel.org/r/20261007234815.4026028-1-jmattson@google.com
Fixes: efa5700ec0da ("perf/amd/ibs: Support IBS_{FETCH|OP}_CTL2[Dis] to eliminate RMW race")
Reported-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Jim Mattson <jmattson@google.com>
Link: https://lore.kernel.org/r/20261007234815.4026028-1-jmattson@google.com
Link: https://patch.msgid.link/20261026041838.941-4-ravi.bangoria@amd.com
Diffstat (limited to 'scripts/Makefile.thinlto')
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