Re: how to speed up "git log"?

From: Junio C Hamano <junkio@cox.net>
Date: Feb 12, 2007, 06:11 UTC
Message-ID: <7vmz3jaorx.fsf@assigned-by-dhcp.cox.net>
In-Reply-To: <20070212060641.GC699@spearce.org>

"Shawn O. Pearce" <spearce@spearce.org> writes:

Show 13 quoted lines

> Junio C Hamano <junkio@cox.net> wrote:
>> I doubt it -- sliding mmap() in the current git, while is a good
>> change overall for handling really huge repos, would most likely
>> perform poorer than the fixed mmap() in 1.4.4 series on
>> platforms with slow mmap(), most notably on MacOS X.
>> 
>> It _might_ be possible that turning some sliding mmap() calls
>> into pread() makes it perform better on MacOS X.
>> 
>> I wonder what happens it git is compiled with NO_MMAP there...
>
> 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?