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| author | Ravi Bangoria <ravi.bangoria@amd.com> | 2026-02-16 07:22:13 +0300 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2026-02-27 18:40:22 +0300 |
| commit | 898138efc99096c3ee836fea439ba6da3cfafa4d (patch) | |
| tree | 3d6297a1df0a46df79d0a55c8dff8cd684cb46ed | |
| parent | 01336b5559785a136de1cac49705f63a70a755bc (diff) | |
| download | linux-898138efc99096c3ee836fea439ba6da3cfafa4d.tar.xz | |
perf/amd/ibs: Limit ldlat->l3missonly dependency to Zen5
The ldlat dependency on l3missonly is specific to Zen 5; newer generations
are not affected. This quirk is documented as an erratum in the following
Revision Guide.
Erratum: 1606 IBS (Instruction Based Sampling) OP Load Latency Filtering
May Capture Unwanted Samples When L3Miss Filtering is Disabled
Revision Guide for AMD Family 1Ah Models 00h-0Fh Processors,
Pub. 58251 Rev. 1.30 July 2025
https://bugzilla.kernel.org/attachment.cgi?id=309193
Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://patch.msgid.link/20260216042216.1440-3-ravi.bangoria@amd.com
| -rw-r--r-- | arch/x86/events/amd/ibs.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c index 705ef43325be..e0b64cb13bf9 100644 --- a/arch/x86/events/amd/ibs.c +++ b/arch/x86/events/amd/ibs.c @@ -356,7 +356,10 @@ static int perf_ibs_init(struct perf_event *event) ldlat >>= 7; config |= (ldlat - 1) << 59; - config |= IBS_OP_L3MISSONLY | IBS_OP_LDLAT_EN; + + config |= IBS_OP_LDLAT_EN; + if (cpu_feature_enabled(X86_FEATURE_ZEN5)) + config |= IBS_OP_L3MISSONLY; } /* |