* Request to backport commit f9cdeb58a9cf ("perf evlist: Avoid frequency mode for the dummy event") to stable versions of Linux kernel
@ 2023-11-01 19:10 Mingwei Zhang
2023-11-04 21:01 ` Sasha Levin
0 siblings, 1 reply; 2+ messages in thread
From: Mingwei Zhang @ 2023-11-01 19:10 UTC (permalink / raw)
To: stable; +Cc: Jim Mattson, Ian Rogers, Stephane Eranian
Hi Greg,
Apology for any inconvenience. This is info and justification for patch.
Commit-id: f9cdeb58a9cf46c09b56f5f661ea8da24b6458c3
Subject: perf evlist: Avoid frequency mode for the dummy event
Justification:
This patch fixes a critical performance issue at perf-tool level for
anything running PMU in a virtualized environment. Majority of the
justification is within the commit message. The only thing I would
like to add is that this patch could save up to 50% of the vCPU time
when running perf in sampling mode with a large number of events in
the VM.
Appreciate your help.
-Mingwei
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: Request to backport commit f9cdeb58a9cf ("perf evlist: Avoid frequency mode for the dummy event") to stable versions of Linux kernel
2023-11-01 19:10 Request to backport commit f9cdeb58a9cf ("perf evlist: Avoid frequency mode for the dummy event") to stable versions of Linux kernel Mingwei Zhang
@ 2023-11-04 21:01 ` Sasha Levin
0 siblings, 0 replies; 2+ messages in thread
From: Sasha Levin @ 2023-11-04 21:01 UTC (permalink / raw)
To: Mingwei Zhang; +Cc: stable, Jim Mattson, Ian Rogers, Stephane Eranian
On Wed, Nov 01, 2023 at 12:10:55PM -0700, Mingwei Zhang wrote:
>Hi Greg,
>
>Apology for any inconvenience. This is info and justification for patch.
>
>Commit-id: f9cdeb58a9cf46c09b56f5f661ea8da24b6458c3
>Subject: perf evlist: Avoid frequency mode for the dummy event
>
>Justification:
>
>This patch fixes a critical performance issue at perf-tool level for
>anything running PMU in a virtualized environment. Majority of the
>justification is within the commit message. The only thing I would
>like to add is that this patch could save up to 50% of the vCPU time
>when running perf in sampling mode with a large number of events in
>the VM.
Queued up, thanks!
--
Thanks,
Sasha
^ permalink raw reply [flat|nested] 2+ messages in thread
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2023-11-01 19:10 Request to backport commit f9cdeb58a9cf ("perf evlist: Avoid frequency mode for the dummy event") to stable versions of Linux kernel Mingwei Zhang
2023-11-04 21:01 ` Sasha Levin
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