linux-kernel - Re: [PATCH RESEND v2] perf/headers: Document PERF_PMU

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <CAP-5=fU2=s+88RQE0iq8DD+mxjMUca4UHkSM3TjkS8T_7p=KKA@mail.gmail.com>
Date: Wed, 12 Nov 2025 08:50:02 -0800
From: Ian Rogers <irogers@...gle.com>
To: Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>
Cc: Nicolas Frattaroli <nicolas.frattaroli@...labora.com>, 
	Arnaldo Carvalho de Melo <acme@...nel.org>, Namhyung Kim <namhyung@...nel.org>, 
	Mark Rutland <mark.rutland@....com>, 
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>, Jiri Olsa <jolsa@...nel.org>, 
	Adrian Hunter <adrian.hunter@...el.com>, kernel@...labora.com, 
	linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org, 
	James Clark <james.clark@...aro.org>, "Mi, Dapeng" <dapeng1.mi@...ux.intel.com>
Subject: Re: [PATCH RESEND v2] perf/headers: Document PERF_PMU_CAP capability flags

On Fri, Oct 10, 2025 at 8:11 PM Mi, Dapeng <dapeng1.mi@...ux.intel.com> wrote:
>
>
> On 9/9/2025 7:39 PM, Nicolas Frattaroli wrote:
> > Over the years, capability flags for perf PMUs were introduced in a
> >
> > piecemeal fashion whenever a new driver needed to signal to the perf
> >
> > core some limitation or special feature.
> >
> >
> >
> > Since one more undocumented flag that can have its meaning inferred from
> >
> > the commit message and implementation never seems that bad, it's
> >
> > understandable that this resulted in a total of 11 undocumented
> >
> > capability flags, which authors of new perf PMU drivers are expected to
> >
> > set correctly for their particular device.
> >
> >
> >
> > Since I am in the process of becoming such an author of a new perf
> >
> > driver, it feels proper to pay it forward by documenting all
> >
> > PERF_PMU_CAP_ constants, so that no future person has to go through an
> >
> > hour or two of git blame + reading perf core code to figure out which
> >
> > capability flags are right for them.
> >
> >
> >
> > Add comments in kernel-doc format that describes each flag. This follows
> >
> > the somewhat verbose "Object-like macro documentation" format, and can
> >
> > be verified with
> >
> >
> >
> >       ./scripts/kernel-doc -v -none include/linux/perf_event.h
> >
> >
> >
> > The current in-tree kernel documentation does not include a page on the
> >
> > perf subsystem, but once it does, these comments should render as proper
> >
> > documentation annotation. Until then, they'll also be quite useful for
> >
> > anyone looking at the header file.
> >
> >
> >
> > Reviewed-by: James Clark <james.clark@...aro.org>
> > Reviewed-by: Ian Rogers <irogers@...gle.com>
> > Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@...labora.com>
> LGTM. Reviewed-by: Dapeng Mi <dapeng1.mi@...ux.intel.com>

Ping.

Thanks,
Ian