From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff King Subject: Re: [PATCH v2] Bump core.deltaBaseCacheLimit to 128MiB Date: Thu, 20 Mar 2014 19:48:59 -0400 Message-ID: <20140320234859.GD7774@sigill.intra.peff.net> References: <1395232712-6412-1-git-send-email-dak@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: git@vger.kernel.org To: David Kastrup X-From: git-owner@vger.kernel.org Fri Mar 21 00:49:07 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 1WQmhu-0006nz-Eo for gcvg-git-2@plane.gmane.org; Fri, 21 Mar 2014 00:49:06 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759673AbaCTXtB (ORCPT ); Thu, 20 Mar 2014 19:49:01 -0400 Received: from cloud.peff.net ([50.56.180.127]:43631 "HELO peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751671AbaCTXtB (ORCPT ); Thu, 20 Mar 2014 19:49:01 -0400 Received: (qmail 29561 invoked by uid 102); 20 Mar 2014 23:49:01 -0000 Received: from c-71-63-4-13.hsd1.va.comcast.net (HELO sigill.intra.peff.net) (71.63.4.13) (smtp-auth username relayok, mechanism cram-md5) by peff.net (qpsmtpd/0.84) with ESMTPA; Thu, 20 Mar 2014 18:49:01 -0500 Received: by sigill.intra.peff.net (sSMTP sendmail emulation); Thu, 20 Mar 2014 19:48:59 -0400 Content-Disposition: inline In-Reply-To: <1395232712-6412-1-git-send-email-dak@gnu.org> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: 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