From: Jeff King <peff@peff.net>
Date: Thu, 20 Mar 2014 23:48:59 GMT
Subject: Re: [PATCH v2] Bump core.deltaBaseCacheLimit to 128MiB
Message-ID: <20140320234859.GD7774@sigill.intra.peff.net>
In-Reply-To: <1395232712-6412-1-git-send-email-dak@gnu.org>

On Wed, Mar 19, 2014 at 01:38:32PM +0100, David Kastrup wrote:

> The default of 16MiB causes serious thrashing for large delta chains
> combined with large files.

Does it make much sense to bump this without also bumping
MAX_DELTA_CACHE in sha1_file.c? In my measurements of linux.git, bumping
the memory limit did not help much without also bumping the number of
slots.

I guess that just bumping the memory limit would help with repos which
have deltas on large-ish files (whereas the kernel just has a lot of
deltas on a lot of little directories), but I'd be curious how much.

If you have before-and-after numbers for just this patch on some
repository, that would be an interesting thing to put in the commit
message.

-Peff