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| author | Kan Liang <[email protected]> | 2025-01-29 15:48:19 +0000 |
|---|---|---|
| committer | Peter Zijlstra <[email protected]> | 2025-02-08 14:47:25 +0000 |
| commit | 47a973fd75639fe80d59f9e1860113bb2a0b112b (patch) | |
| tree | b19bd0363572535dabbd5e1a65088b42fd6fd624 /lib/net_utils.c | |
| parent | perf/x86/intel: Clean up PEBS-via-PT on hybrid (diff) | |
| download | kernel-47a973fd75639fe80d59f9e1860113bb2a0b112b.tar.gz kernel-47a973fd75639fe80d59f9e1860113bb2a0b112b.zip | |
perf/x86/intel: Fix ARCH_PERFMON_NUM_COUNTER_LEAF
The EAX of the CPUID Leaf 023H enumerates the mask of valid sub-leaves.
To tell the availability of the sub-leaf 1 (enumerate the counter mask),
perf should check the bit 1 (0x2) of EAS, rather than bit 0 (0x1).
The error is not user-visible on bare metal. Because the sub-leaf 0 and
the sub-leaf 1 are always available. However, it may bring issues in a
virtualization environment when a VMM only enumerates the sub-leaf 0.
Introduce the cpuid35_e?x to replace the macros, which makes the
implementation style consistent.
Fixes: eb467aaac21e ("perf/x86/intel: Support Architectural PerfMon Extension leaf")
Signed-off-by: Kan Liang <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Diffstat (limited to 'lib/net_utils.c')
0 files changed, 0 insertions, 0 deletions