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[v4,4/4] perf/x86/amd: don't reject non-sampling events with configured LBR

Message ID 20240331041830.2806741-5-andrii@kernel.org (mailing list archive)
State Superseded
Headers show
Series perf/x86/amd: add LBR capture support outside of hardware events | expand

Checks

Context Check Description
netdev/tree_selection success Not a local patch

Commit Message

Andrii Nakryiko March 31, 2024, 4:18 a.m. UTC 
Now that it's possible to capture LBR on AMD CPU from BPF at arbitrary
point, there is no reason to artificially limit this feature to just
sampling events. So corresponding check is removed. AFAIU, there is no
correctness implications of doing this (and it was possible to bypass
this check by just setting perf_event's sample_period to 1 anyways, so
it doesn't guard all that much).

Reviewed-by: Sandipan Das <sandipan.das@amd.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
 arch/x86/events/amd/lbr.c | 4 ----
 1 file changed, 4 deletions(-)
diff mbox series

Patch

diff --git a/arch/x86/events/amd/lbr.c b/arch/x86/events/amd/lbr.c
index 0e4de028590d..75920f895d67 100644
--- a/arch/x86/events/amd/lbr.c
+++ b/arch/x86/events/amd/lbr.c
@@ -310,10 +310,6 @@  int amd_pmu_lbr_hw_config(struct perf_event *event)
 {
 	int ret = 0;
 
-	/* LBR is not recommended in counting mode */
-	if (!is_sampling_event(event))
-		return -EINVAL;
-
 	ret = amd_pmu_lbr_setup_filter(event);
 	if (!ret)
 		event->attach_state |= PERF_ATTACH_SCHED_CB;