Subject: Re: how to speed up "git log"?

From: "Shawn O. Pearce" <[email-masked]>
Date: Mon, 12 Feb 2007 01:22:24 -0500

Junio C Hamano <[email-masked]> wrote:
> "Shawn O. Pearce" <[email-masked]> writes:
> > So I ran three trials, v1.5.0-rc4-26-gcc46a74 with and without
> > NO_MMAP against v1.4.4.4 on a freshly repacked git.git.
> 
> I do not think freshly repacked git.git is a good test case for
> a real-world workload where this really matters.  Doesn't your
> default pack window large enough to cover it with a single
> window, or perhaps two at most?

Its one window, maybe two, as git.git is ~12 MiB and the window
size is 1 MiB (NO_MMAP) or 32 MiB (with mmap).

On linux.git:

v150-mmap:
        2.23 real         1.99 user         0.10 sys
        2.19 real         1.98 user         0.10 sys
        2.19 real         1.98 user         0.10 sys

v150-nommap:
        2.63 real         1.99 user         0.50 sys
        2.67 real         1.98 user         0.51 sys
        2.63 real         1.99 user         0.51 sys

v1444:
        2.15 real         1.94 user         0.09 sys
        2.19 real         1.95 user         0.10 sys
        2.16 real         1.94 user         0.10 sys

Again, we aren't too far away from v1.4.4.4, but the NO_MMAP clearly
is hurting us, even on Mac OS X.

-- 
Shawn.