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References: <20201216090556.813996-1-namhyung@kernel.org> <20201216090556.813996-3-namhyung@kernel.org>
 <20201229115158.GH521329@kernel.org>
In-Reply-To: <20201229115158.GH521329@kernel.org>
From:   Namhyung Kim <namhyung@kernel.org>
Date:   Wed, 6 Jan 2021 10:33:43 +0900
Message-ID: <CAM9d7cidFuM5gmjq8=uy+mJjHHEVE=q6qESkc_OeTeGEQkGbnA@mail.gmail.com>
Subject: Re: [PATCH 3/3] tools/lib/fs: Cache cgroupfs mount point
To:     Arnaldo Carvalho de Melo <acme@kernel.org>
Cc:     Jiri Olsa <jolsa@redhat.com>, Ingo Molnar <mingo@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Stephane Eranian <eranian@google.com>,
        Ian Rogers <irogers@google.com>,
        Andi Kleen <ak@linux.intel.com>
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Hi Arnaldo,

On Tue, Dec 29, 2020 at 8:51 PM Arnaldo Carvalho de Melo
<acme@kernel.org> wrote:
>
> Em Wed, Dec 16, 2020 at 06:05:56PM +0900, Namhyung Kim escreveu:
> > Currently it parses the /proc file everytime it opens a file in the
> > cgroupfs.  Save the last result to avoid it (assuming it won't be
> > changed between the accesses).
>
> Which is the most likely case, but can't we use something like inotify
> to detect that and bail out or warn the user?

Hmm.. looks doable.  Will check.

Thanks,
Namhyung