From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: "Alex Xu (Hello71)" <alex_y_xu@yahoo.ca>
Cc: mingo@redhat.com, peterz@infradead.org,
Tony Garnock-Jones <tonyg@leastfixedpoint.com>,
linux-perf-users@vger.kernel.org
Subject: Re: [PATCH] tools/perf: Use long-running addr2line per dso
Date: Thu, 9 Sep 2021 17:19:26 -0300 [thread overview]
Message-ID: <YTpsTpyczphPtADn@kernel.org> (raw)
In-Reply-To: <1631205749.uhek9ofd69.none@localhost>
Em Thu, Sep 09, 2021 at 12:52:31PM -0400, Alex Xu (Hello71) escreveu:
> Excerpts from Tony Garnock-Jones's message of September 9, 2021 7:22 am:
> > Invoking addr2line in a separate subprocess, one for each required
> > lookup, takes a terribly long time. This patch introduces a
> > long-running addr2line process for each dso, *DRAMATICALLY* speeding
> > up runs of perf. What used to take tens of minutes now takes tens of
> > seconds.
> >
> > Debian bug report about this issue:
> > https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=911815
> >
> > Signed-off-by: Tony Garnock-Jones <tonyg@leastfixedpoint.com>
>
> This patch seems awfully complicated, especially considering it still
> uses relatively slow stdio instead of direct library calls. Did you look
> into calling elfutils instead of libbfd if the latter is not available?
That would be better, indeed, but since nobody has worked on this area
for white some time and we have it in a far worse shape right now, I'm
inclined to accept his work after I have time to review it.
> It is GPLv2 compatible, so can be linked against perf for distribution.
> Additionally, elfutils is already used by perf for unwinding, but not
> addr2line.
> On the patch specifically, why was popen changed to socketpair? It looks
> like it adds significant complexity, and the advanced features of
> socketpair are not being used (SOCK_DGRAM/SOCK_SEQPACKET, SCM_RIGHTS).
Valid questions, perhaps we can get what Tony did and improve it and
then try working with the library.
- Arnaldo
next prev parent reply other threads:[~2021-09-09 20:19 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-09 11:22 [PATCH] tools/perf: Use long-running addr2line per dso Tony Garnock-Jones
2021-09-09 16:52 ` Alex Xu (Hello71)
2021-09-09 20:19 ` Arnaldo Carvalho de Melo [this message]
2021-09-10 8:58 ` Tony Garnock-Jones
2021-09-10 8:54 ` Tony Garnock-Jones
2021-09-09 19:05 ` Ian Rogers
2021-09-10 8:57 ` Tony Garnock-Jones
2021-09-10 10:23 ` [PATCH v2] " Tony Garnock-Jones
2021-09-10 22:45 ` Ian Rogers
2021-09-10 22:55 ` Tony Garnock-Jones
2021-09-10 22:55 ` [PATCH v3] " Tony Garnock-Jones
2021-09-11 0:25 ` Ian Rogers
2021-09-13 20:05 ` Arnaldo Carvalho de Melo
2021-09-16 12:09 ` [PATCH v4] " Tony Garnock-Jones
2021-10-01 0:29 ` Ian Rogers
2021-10-01 1:20 ` Arnaldo Carvalho de Melo
2021-10-04 12:29 ` Arnaldo Carvalho de Melo
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