From: Jeff King <peff@peff.net>
To: Shawn Pearce <spearce@spearce.org>
Cc: Junio C Hamano <gitster@pobox.com>, git <git@vger.kernel.org>
Subject: Re: [PATCH 0/2] optimizing pack access on "read only" fetch repos
Date: Fri, 1 Feb 2013 04:14:31 -0500 [thread overview]
Message-ID: <20130201091431.GC30644@sigill.intra.peff.net> (raw)
In-Reply-To: <CAJo=hJuGw8x=VrjWhvZhzakuhWrCWr2FRuEsNt5gQNC=6PPuVw@mail.gmail.com>
On Thu, Jan 31, 2013 at 08:47:37AM -0800, Shawn O. Pearce wrote:
> >> - System resource cost we incur by having to keep 50 file
> >> descriptors open and maintaining 50 mmap windows will reduce by
> >> 50 fold.
> >
> > I wonder how measurable that is (and if it matters on Linux versus less
> > efficient platforms).
>
> It does matter. We know it has a negative impact on JGit even on Linux
> for example. You don't want 300 packs in a repository. 50 might be
> tolerable. 300 is not.
I'd love to see numbers if you have them. It's not that I don't believe
it is slower, but knowing _how much_ is important when thinking about
what kind of performance increase we are looking to get (which in turn
impacts how much effort to put into the repacking).
-Peff
next prev parent reply other threads:[~2013-02-01 9:14 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-26 22:40 [PATCH 0/2] optimizing pack access on "read only" fetch repos Jeff King
2013-01-26 22:40 ` [PATCH 1/2] fetch: run gc --auto after fetching Jeff King
2013-01-27 1:51 ` Jonathan Nieder
[not found] ` <87bmopzbqx.fsf@gmail.com>
2017-07-12 20:00 ` git gc --auto aquires *.lock files that make a subsequent git-fetch error out Jeff King
2017-07-12 20:30 ` Ævar Arnfjörð Bjarmason
2017-07-12 20:43 ` Jeff King
2013-01-26 22:40 ` [PATCH 2/2] fetch-pack: avoid repeatedly re-scanning pack directory Jeff King
2013-01-27 10:27 ` Jonathan Nieder
2013-01-27 20:09 ` Junio C Hamano
2013-01-27 23:20 ` Jonathan Nieder
2013-01-27 6:32 ` [PATCH 0/2] optimizing pack access on "read only" fetch repos Junio C Hamano
2013-01-29 8:06 ` Shawn Pearce
2013-01-29 8:29 ` Jeff King
2013-01-29 15:25 ` Martin Fick
2013-01-29 15:58 ` Junio C Hamano
2013-01-29 21:19 ` Jeff King
2013-01-29 22:26 ` Junio C Hamano
2013-01-31 16:47 ` Shawn Pearce
2013-02-01 9:14 ` Jeff King [this message]
2013-02-02 10:07 ` Shawn Pearce
2013-01-29 11:01 ` Duy Nguyen
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