linux-kernel - Re: [PATCH RESEND] perf: Completely remove possibility to override MAX_NR

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Message-ID: <aMR2FZWyXekLEK0-@x1>
Date: Fri, 12 Sep 2025 16:35:49 -0300
From: Arnaldo Carvalho de Melo <acme@...nel.org>
To: Christophe Leroy <christophe.leroy@...roup.eu>
Cc: Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>,
	Namhyung Kim <namhyung@...nel.org>,
	Mark Rutland <mark.rutland@....com>,
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
	Jiri Olsa <jolsa@...nel.org>, Ian Rogers <irogers@...gle.com>,
	Adrian Hunter <adrian.hunter@...el.com>,
	"Liang, Kan" <kan.liang@...ux.intel.com>, Leo Yan <leo.yan@....com>,
	linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org,
	bpf@...r.kernel.org
Subject: Re: [PATCH RESEND] perf: Completely remove possibility to override
 MAX_NR_CPUS

On Fri, Sep 12, 2025 at 10:32:56AM +0200, Christophe Leroy wrote:
> Le 18/08/2025 à 11:57, Christophe Leroy a écrit :
> > Commit 21b8732eb447 ("perf tools: Allow overriding MAX_NR_CPUS at
> > compile time") added the capability to override MAX_NR_CPUS. At
> > that time it was necessary to reduce the huge amount of RAM used
> > by static stats variables.
> > 
> > But this has been unnecessary since commit 6a1e2c5c2673 ("perf stat:
> > Remove a set of shadow stats static variables"), and
> > commit e8399d34d568 ("libperf cpumap: Hide/reduce scope of
> > MAX_NR_CPUS") broke the build in that case because it failed to
> > add the guard around the new definition of MAX_NR_CPUS.
> > 
> > So cleanup things and remove guards completely to officialise it
> > is not necessary anymore to override MAX_NR_CPUS.
> > 
> > Link: https://lore.kernel.org/all/8c8553387ebf904a9e5a93eaf643cb01164d9fb3.1736188471.git.christophe.leroy@csgroup.eu/
> > Fixes: e8399d34d568 ("libperf cpumap: Hide/reduce scope of MAX_NR_CPUS")
> > Signed-off-by: Christophe Leroy <christophe.leroy@...roup.eu>
> 
> Gentle ping

Thanks, applied to perf-tools-next,

- Arnaldo