lkml.org 
[lkml]   [2024]   [Mar]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v2] perf/x86/amd: support capturing LBR from software events

* Andrii Nakryiko <andrii@kernel.org> wrote:

> 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 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).

> diff --git a/arch/x86/events/amd/lbr.c b/arch/x86/events/amd/lbr.c
> index 4a1e600314d5..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;
> -

Could you please split out this change into a separate patch?

Thanks,

Ingo

\
 
 \ /
  Last update: 2024-05-27 16:14    [W:0.052 / U:0.328 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site