From: ZheNing Hu <adlternative@gmail.com>
To: Jeff King <peff@peff.net>
Cc: Git List <git@vger.kernel.org>
Subject: Re: [hacky PATCH 0/2] speeding up trivial for-each-ref invocations
Date: Mon, 6 Sep 2021 21:30:45 +0800 [thread overview]
Message-ID: <CAOLTT8SYx4f8x-0zjXLJVOpW4-Mj34mjsfwr6tWo0PbZAV9B0w@mail.gmail.com> (raw)
In-Reply-To: <YTS8yiYwR+eeZf4+@coredump.intra.peff.net>
Jeff King <peff@peff.net> 于2021年9月5日周日 下午8:49写道:
>
> On Sun, Sep 05, 2021 at 04:19:53PM +0800, ZheNing Hu wrote:
>
> > > In this version there are 2 patches, tested against 'git for-each-ref
> > > --format="%(objectname) %(refname)"' on a fully packed repo with 500k
> > > refs:
> > >
> >
> > Regarding this 500k refs, is there any way I can reproduce it?
>
> Try this in a clone of linux.git (or any other repo):
>
> git rev-list HEAD |
> head -500000 |
> perl -lne 'print "create refs/foo/$. $_"' |
> git update-ref --stdin
>
> git pack-refs --all --prune
>
Sorry, It seems that the above command is difficult to complete on my
machine (it took more than ten minutes). It may be stuck on git update-ref.
So I tried to reproduce it in a repo which containing 76K refs:
Benchmark #1: jk-for-each-ref-speedup~2: git for-each-ref
--format='%(refname) %(objectname)'
Time (mean ± σ): 108.0 ms ± 1.9 ms [User: 55.2 ms, System: 52.1 ms]
Range (min … max): 105.7 ms … 112.4 ms 26 runs
Benchmark #2: jk-for-each-ref-speedup~1: git for-each-ref
--format='%(refname) %(objectname)'
Time (mean ± σ): 88.2 ms ± 1.7 ms [User: 44.8 ms, System: 43.1 ms]
Range (min … max): 85.8 ms … 93.2 ms 32 runs
Benchmark #3:jk-for-each-ref-speedup: git for-each-ref
--format='%(refname) %(objectname)'
Time (mean ± σ): 69.0 ms ± 2.0 ms [User: 22.7 ms, System: 46.1 ms]
Range (min … max): 66.2 ms … 74.1 ms 41 runs
For %(refname) and %(objectname), this performance optimization is
indeed amazing.
> Though I actually think for these tests that it is not important that
> each ref point to a unique commit (we are not opening up the objects at
> all, and just treating the oids as strings).
>
> -Peff
Thanks.
--
ZheNing Hu
next prev parent reply other threads:[~2021-09-06 13:31 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-04 12:40 [hacky PATCH 0/2] speeding up trivial for-each-ref invocations Jeff King
2021-09-04 12:41 ` [PATCH 1/2] ref-filter: hacky "streaming" mode Jeff King
2021-09-05 8:20 ` ZheNing Hu
2021-09-05 13:04 ` Jeff King
2021-09-07 5:28 ` ZheNing Hu
2021-09-07 18:01 ` Jeff King
2021-09-09 14:45 ` ZheNing Hu
2021-09-10 14:26 ` Jeff King
2021-09-15 12:27 ` ZheNing Hu
2021-09-15 14:23 ` ZheNing Hu
2021-09-16 21:45 ` Jeff King
2021-09-20 7:42 ` ZheNing Hu
2021-09-16 21:31 ` Jeff King
2021-09-05 13:15 ` Jeff King
2021-09-07 5:42 ` ZheNing Hu
2021-09-04 12:42 ` [PATCH 2/2] ref-filter: implement "quick" formats Jeff King
2021-09-05 8:20 ` ZheNing Hu
2021-09-05 13:07 ` Jeff King
2021-09-06 13:34 ` ZheNing Hu
2021-09-07 20:06 ` Junio C Hamano
2021-09-05 8:19 ` [hacky PATCH 0/2] speeding up trivial for-each-ref invocations ZheNing Hu
2021-09-05 12:49 ` Jeff King
2021-09-06 13:30 ` ZheNing Hu [this message]
2021-09-07 17:28 ` Jeff King
2021-09-09 13:20 ` ZheNing Hu
2021-09-06 6:54 ` Patrick Steinhardt
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