mirror of
git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs.git
synced 2026-11-09 02:51:11 +01:00
Kan Liang
4e949e9b9d
The SMM freeze feature was introduced since PerfMon V2. But the current
code unconditionally enables the feature for all platforms. It can
generate #GP exception, if the related FREEZE_WHILE_SMM bit is set for
the machine with PerfMon V1.
To disable the feature for PerfMon V1, perf needs to
- Remove the freeze_on_smi sysfs entry by moving intel_pmu_attrs to
intel_pmu, which is only applied to PerfMon V2 and later.
- Check the PerfMon version before flipping the SMM bit when starting CPU
Fixes: 6089327f54 ("perf/x86: Add sysfs entry to freeze counters on SMI")
Signed-off-by: Kan Liang <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]