Commit 9794563d authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Ingo Molnar
Browse files

perf/x86/amd: Don't reject non-sampling events with configured LBR 



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).

Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Reviewed-by: default avatarSandipan Das <sandipan.das@amd.com>
Link: https://lore.kernel.org/r/20240402022118.1046049-5-andrii@kernel.org
parent a4d18112

arch/x86/events/amd/lbr.c

+0 −4
Original line number Diff line number Diff line
@@ -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;