All of lore.kernel.org
 help / color / mirror / Atom feed
From: Namhyung Kim <namhyung@kernel.org>
To: Ian Rogers <irogers@google.com>
Cc: "Peter Zijlstra" <peterz@infradead.org>,
	"Ingo Molnar" <mingo@redhat.com>,
	"Arnaldo Carvalho de Melo" <acme@kernel.org>,
	"Mark Rutland" <mark.rutland@arm.com>,
	"Alexander Shishkin" <alexander.shishkin@linux.intel.com>,
	"Jiri Olsa" <jolsa@kernel.org>,
	"Adrian Hunter" <adrian.hunter@intel.com>,
	"Kan Liang" <kan.liang@linux.intel.com>,
	"Sam James" <sam@gentoo.org>,
	"Jesper Juhl" <jesperjuhl76@gmail.com>,
	"James Clark" <james.clark@linaro.org>,
	"Zhongqiu Han" <quic_zhonhan@quicinc.com>,
	"Yicong Yang" <yangyicong@hisilicon.com>,
	"Thomas Richter" <tmricht@linux.ibm.com>,
	"Michael Petlan" <mpetlan@redhat.com>,
	"Anne Macedo" <retpolanne@posteo.net>,
	"Dominique Martinet" <asmadeus@codewreck.org>,
	"Jean-Philippe Romain" <jean-philippe.romain@foss.st.com>,
	"Junhao He" <hejunhao3@huawei.com>,
	linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
	"Krzysztof Łopatowski" <krzysztof.m.lopatowski@gmail.com>
Subject: Re: [PATCH v3 0/8] Add io_dir to avoid memory overhead from opendir
Date: Mon, 24 Feb 2025 16:30:22 -0800	[thread overview]
Message-ID: <Z70PHtvzjHDLx42A@google.com> (raw)
In-Reply-To: <Z70OqFzD2JcbhFtL@google.com>

On Mon, Feb 24, 2025 at 04:28:24PM -0800, Namhyung Kim wrote:
> Hi Ian,
> 
> On Fri, Feb 21, 2025 at 10:10:05PM -0800, Ian Rogers wrote:
> > glibc's opendir allocates a minimum of 32kb, when called recursively
> > for a directory tree the memory consumption can add up - nearly 300kb
> > during perf start-up when processing modules. Add a stack allocated
> > variant of readdir sized a little more than 1kb
> 
> It's still small and hard to verify.  I've run the following command
> before and after the change but didn't see a difference.
> 
>   $ sudo time -f %Mk ./perf record -a true
>   [ perf record: Woken up 1 times to write data ]
>   [ perf record: Captured and wrote 1.757 MB perf.data (563 samples) ]
>   74724k
> 
> According to man time(1), %M is for max RSS.

But anyway, it looks ok and build is fine now.

Thanks,
Namhyung


  reply	other threads:[~2025-02-25  0:30 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-02-22  6:10 [PATCH v3 0/8] Add io_dir to avoid memory overhead from opendir Ian Rogers
2025-02-22  6:10 ` [PATCH v3 1/8] tools lib api: Add io_dir an allocation free readdir alternative Ian Rogers
2025-02-22  6:10 ` [PATCH v3 2/8] perf maps: Switch modules tree walk to io_dir__readdir Ian Rogers
2025-02-22  6:10 ` [PATCH v3 3/8] perf pmu: Switch " Ian Rogers
2025-02-22  6:10 ` [PATCH v3 4/8] perf header: Switch mem topology " Ian Rogers
2025-02-22  6:10 ` [PATCH v3 5/8] perf events: Remove scandir in thread synthesis Ian Rogers
2025-02-22  6:10 ` [PATCH v3 6/8] perf parse-events: Switch tracepoints to io_dir__readdir Ian Rogers
2025-02-22  6:10 ` [PATCH v3 7/8] perf hwmon_pmu: Switch event discovery " Ian Rogers
2025-02-22  6:10 ` [PATCH v3 8/8] perf machine: Reuse module path buffer Ian Rogers
2025-02-25  0:28 ` [PATCH v3 0/8] Add io_dir to avoid memory overhead from opendir Namhyung Kim
2025-02-25  0:30   ` Namhyung Kim [this message]
2025-02-25  1:25     ` Ian Rogers
2025-02-25 21:58 ` Namhyung Kim

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=Z70PHtvzjHDLx42A@google.com \
    --to=namhyung@kernel.org \
    --cc=acme@kernel.org \
    --cc=adrian.hunter@intel.com \
    --cc=alexander.shishkin@linux.intel.com \
    --cc=asmadeus@codewreck.org \
    --cc=hejunhao3@huawei.com \
    --cc=irogers@google.com \
    --cc=james.clark@linaro.org \
    --cc=jean-philippe.romain@foss.st.com \
    --cc=jesperjuhl76@gmail.com \
    --cc=jolsa@kernel.org \
    --cc=kan.liang@linux.intel.com \
    --cc=krzysztof.m.lopatowski@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-perf-users@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=mingo@redhat.com \
    --cc=mpetlan@redhat.com \
    --cc=peterz@infradead.org \
    --cc=quic_zhonhan@quicinc.com \
    --cc=retpolanne@posteo.net \
    --cc=sam@gentoo.org \
    --cc=tmricht@linux.ibm.com \
    --cc=yangyicong@hisilicon.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.