From: Pavel Machek <pavel@ucw.cz>
To: Ingo Molnar <mingo@kernel.org>
Cc: David Ahern <dsahern@gmail.com>,
git@vger.kernel.org,
Arnaldo Carvalho de Melo <acme@infradead.org>,
linux-kernel@vger.kernel.org, Andrew Vagin <avagin@openvz.org>,
Borislav Petkov <bp@amd64.org>,
David Howells <dhowells@redhat.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
Paul Mackerras <paulus@samba.org>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Stephane Eranian <eranian@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
arnaldo.melo@gmail.com,
Arnaldo Carvalho de Melo <acme@redhat.com>
Subject: Re: 'git describe' is very slow on development trees with lots of commits
Date: Wed, 31 Oct 2012 18:52:26 +0100 [thread overview]
Message-ID: <20121031175226.GB20660@elf.ucw.cz> (raw)
In-Reply-To: <20121027133352.GB30001@gmail.com>
Hi!
> (Cc:-ed the Git development list.)
>
> * David Ahern <dsahern@gmail.com> wrote:
>
> > PERF-VERSION-GEN and specifically the git commands are the
> > cause of more delay than the config checks, especially when
> > doing the build in a VM with the kernel source on an NFS
> > mount.
>
> Yes, I have noticed that too.
....
> The cost on this pretty fast machine is about 1 msecs per commit
> - which adds up to about 2.5 seconds during much of the
> development cycle.
Well... I noticed my builds when little changed are very slow... and
it was due to the computation of version string. Ouch.
pavel@amd:~/mainline-altera/linux$ time git describe
fixes-for-linus-506-g71ca8691
0.68user 0.22system 27.82 (0m27.820s) elapsed 3.26%CPU
pavel@amd:~/mainline-altera/linux$
(Cached it is more reasonable 3 seconds, but it keeps going out of
cache all the time. Uncached clean build is 3 minutes, cached is 9
seconds + time to do git describe).
Thikpad X60.
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
next prev parent reply other threads:[~2012-10-31 17:52 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-26 14:31 [GIT PULL 0/9] perf/core improvements and fixes Arnaldo Carvalho de Melo
2012-10-26 14:31 ` [PATCH 1/9] tools lib traceevent: Do not generate dependency for system header files Arnaldo Carvalho de Melo
2012-10-26 14:31 ` [PATCH 2/9] perf tools: Cleanup doc related targets Arnaldo Carvalho de Melo
2012-10-26 14:31 ` [PATCH 3/9] perf tools: Convert invocation of MAKE into SUBDIR Arnaldo Carvalho de Melo
2012-10-26 14:31 ` [PATCH 4/9] perf tools: Always show CHK message when doing try-cc Arnaldo Carvalho de Melo
2012-10-26 14:31 ` [PATCH 5/9] perf tools: Fix LIBELF_MMAP checking Arnaldo Carvalho de Melo
2012-10-26 14:31 ` [PATCH 6/9] perf inject: Work with files Arnaldo Carvalho de Melo
2012-10-26 14:31 ` [PATCH 7/9] perf inject: Merge sched_stat_* and sched_switch events Arnaldo Carvalho de Melo
2012-10-26 14:31 ` [PATCH 8/9] perf inject: Mark a dso if it's used Arnaldo Carvalho de Melo
2012-10-26 14:31 ` [PATCH 9/9] perf stat: Add --pre and --post command Arnaldo Carvalho de Melo
2012-10-26 14:54 ` [GIT PULL 0/9] perf/core improvements and fixes Ingo Molnar
2012-10-26 15:06 ` David Ahern
2012-10-26 15:31 ` Namhyung Kim
2012-10-26 15:34 ` Borislav Petkov
2012-10-26 16:31 ` Arnaldo Carvalho de Melo
2012-10-26 17:20 ` Borislav Petkov
2012-10-27 9:16 ` Namhyung Kim
2012-10-27 14:29 ` Arnaldo Carvalho de Melo
2012-10-27 17:12 ` stephane eranian
2012-10-27 13:33 ` 'git describe' is very slow on development trees with lots of commits Ingo Molnar
2012-10-31 17:52 ` Pavel Machek [this message]
2012-10-26 17:05 ` [GIT PULL 0/9] perf/core improvements and fixes Arnaldo Carvalho de Melo
2012-10-27 13:19 ` Ingo Molnar
2012-10-30 8:18 ` Ingo Molnar
2012-10-30 8:21 ` Peter Zijlstra
2012-10-30 9:14 ` Ingo Molnar
2012-10-30 8:46 ` [PATCH] perf tools: Speed up the perf build time by simplifying the perf --version string generation Ingo Molnar
2012-10-30 9:35 ` Arnaldo Carvalho de Melo
2012-10-30 9:43 ` Ingo Molnar
2012-10-30 9:48 ` Ingo Molnar
2012-10-30 9:57 ` Arnaldo Carvalho de Melo
2012-10-30 10:01 ` Ingo Molnar
2012-10-30 9:49 ` Arnaldo Carvalho de Melo
2012-11-14 6:32 ` [tip:perf/core] " tip-bot for Ingo Molnar
2012-10-30 8:54 ` [PATCH] perf tools: Further speed up the perf build Ingo Molnar
2012-11-14 6:33 ` [tip:perf/core] " tip-bot for Ingo Molnar
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