From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Kastrup Subject: Re: [PATCH v2] Bump core.deltaBaseCacheLimit to 128MiB Date: Fri, 21 Mar 2014 07:12:40 +0100 Message-ID: <87txascc6f.fsf@fencepost.gnu.org> References: <1395232712-6412-1-git-send-email-dak@gnu.org> <20140320234859.GD7774@sigill.intra.peff.net> Mime-Version: 1.0 Content-Type: text/plain Cc: git@vger.kernel.org To: Jeff King X-From: git-owner@vger.kernel.org Fri Mar 21 08:48:14 2014 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1WQuBa-0006Gr-C2 for gcvg-git-2@plane.gmane.org; Fri, 21 Mar 2014 08:48:14 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755016AbaCUHsB (ORCPT ); Fri, 21 Mar 2014 03:48:01 -0400 Received: from fencepost.gnu.org ([208.118.235.10]:41250 "EHLO fencepost.gnu.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754768AbaCUHsA (ORCPT ); Fri, 21 Mar 2014 03:48:00 -0400 Received: from localhost ([127.0.0.1]:40286 helo=lola) by fencepost.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WQuBL-00025N-DI; Fri, 21 Mar 2014 03:47:59 -0400 Received: by lola (Postfix, from userid 1000) id D0DFDE08C8; Fri, 21 Mar 2014 07:12:40 +0100 (CET) In-Reply-To: <20140320234859.GD7774@sigill.intra.peff.net> (Jeff King's message of "Thu, 20 Mar 2014 19:48:59 -0400") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3.50 (gnu/linux) Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Jeff King writes: > 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. In the cases I checked, bumping MAX_DELTA_CACHE did not help much. Bumping it once to 512 could be a slight improvement; larger values then caused performance to regress. > 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), Well, those were the most pathological for git-blame so I was somewhat focused on them. > but I'd be curious how much. http://repo.or.cz/r/wortliste.git consists basically of adding lines to a single alphabetically sorted file wortliste of currently size 15MB. -- David Kastrup