Received-SPF: pass (google.com: domain of linux-kernel+bounces-189706-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) client-ip=2604:1380:45d1:ec00::1;
Date: Sun, 26 May 2024 17:58:38 +0800
From: Leo Yan <leo.yan@linux.dev>
To: Ian Rogers <irogers@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Namhyung Kim <namhyung@kernel.org>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>, Ingo Molnar <mingo@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>, Jiri Olsa <jolsa@kernel.org>,
	Adrian Hunter <adrian.hunter@intel.com>,
	Clark Williams <williams@redhat.com>,
	Kate Carcia <kcarcia@redhat.com>, linux-kernel@vger.kernel.org,
	linux-perf-users@vger.kernel.org,
	Anne Macedo <retpolanne@posteo.net>,
	Bhaskar Chowdhury <unixbhaskar@gmail.com>,
	Ethan Adams <j.ethan.adams@gmail.com>,
	James Clark <james.clark@arm.com>,
	Kan Liang <kan.liang@linux.intel.com>,
	Thomas Richter <tmricht@linux.ibm.com>,
	Tycho Andersen <tycho@tycho.pizza>,
	Yang Jihong <yangjihong@bytedance.com>
Subject: Re: [GIT PULL] perf tools changes for v6.10
Message-ID: <20240526095838.GA33806@debian-dev>
References: <CAHk-=wiWvtFyedDNpoV7a8Fq_FpbB+F5KmWK2xPY3QoYseOf_A@mail.gmail.com>
 <ZlFE-wbwStOqt8Ra@x1>
 <ZlFGpxWGQskCTjeK@x1>
 <CAP-5=fXDdcjMmn8iBenjPmZZQdB=AX+gc4TYDsHXuwH9TYq4Ng@mail.gmail.com>
 <CAHk-=wheZptGieaObmQEsz6bocUjhQXNpWXFDmCK-TOKbOvO+Q@mail.gmail.com>
 <CAM9d7chXVsoNP6uYMCqy2MZOiWkt4GrFn+giYLHQjaJRsap1Cw@mail.gmail.com>
 <CAHk-=wjY7CG5WRZQ3E1gdEO9YtUQstMe7a=ciShY0wz0hKXyuQ@mail.gmail.com>
 <CAP-5=fUvT+O0iyXxst3WKqnWdpimqD8+aX8GJU7_7zYieniYxQ@mail.gmail.com>
 <CAHk-=wjMvgsBu5n9ifs5d8Qfu8x23=XmXgp6gXYNEN2y-g5UMA@mail.gmail.com>
 <CAP-5=fWk-eDfuRH-tL5TWU8dXumOnCTKby5VKonOfjGad4TG=Q@mail.gmail.com>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <CAP-5=fWk-eDfuRH-tL5TWU8dXumOnCTKby5VKonOfjGad4TG=Q@mail.gmail.com>

Hi Ian,

On Sat, May 25, 2024 at 11:22:08PM -0700, Ian Rogers wrote:

[...]

> In doing that work the code was tested by IBM for S390 and by Intel,
> but it was fixing an ARM created problem. ARM were the first to have
> BIG.little systems but contributed nothing to the perf tool to handle
> it, even though each core type has a different PMU. ARM BIG.little
> remains broken with the perf tool and when I fix it for them they
> don't review or test the code. ARM changed and left unworking uncore
> PMU naming conventions. ARM don't fix tests for their platform. ARM
> don't help make perf's tests cover their different way of naming PMUs.
> No one is trying to break ARM machines, but when ARM fails to do
> anything other than review their own changes in the perf tree it is
> something of an inevitability.
> 
> Fwiw, I am working on making perf record, perf top, etc. skip events
> on non-core PMUs when they fail to open. It is a rather large and ugly
> change. It is also a holiday weekend and I'm spending a lot of my time
> in it addressing latent ARM problems.

James is in holiday, so I should cover this in time. Sorry that I did
not respond the issue quickly - mainly as I am not familiar with JSON
and perf event part.

I tried to reproduce the issue reported by Linus on my Arm big.LITTLE
system but cannot reproduce it. As I saw Linus mentioned the issue is
related with Arm DSU event, which is absent on my test board.

But your complaint is received well and I am very appreciate your work
(especially in the weekend). I will continue to look into the details
in this thread, and monitor incoming patches and I will verify them.

Thanks,
Leo