From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolas Pitre Subject: Re: [PATCH] basic threaded delta search Date: Thu, 06 Sep 2007 02:23:38 -0400 (EDT) Message-ID: References: <11890591912193-git-send-email-nico@cam.org> <11890591923123-git-send-email-nico@cam.org> <11890591923270-git-send-email-nico@cam.org> <1189059193250-git-send-email-nico@cam.org> <85ps0wfh8h.fsf@lola.goethe.zz> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Content-Transfer-Encoding: 7BIT Cc: Junio C Hamano , git@vger.kernel.org To: David Kastrup X-From: git-owner@vger.kernel.org Thu Sep 06 08:23:48 2007 Return-path: Envelope-to: gcvg-git@gmane.org Received: from vger.kernel.org ([209.132.176.167]) by lo.gmane.org with esmtp (Exim 4.50) id 1ITAmG-0003gV-NT for gcvg-git@gmane.org; Thu, 06 Sep 2007 08:23:45 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756345AbXIFGXj (ORCPT ); Thu, 6 Sep 2007 02:23:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756679AbXIFGXj (ORCPT ); Thu, 6 Sep 2007 02:23:39 -0400 Received: from relais.videotron.ca ([24.201.245.36]:48434 "EHLO relais.videotron.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754354AbXIFGXi (ORCPT ); Thu, 6 Sep 2007 02:23:38 -0400 Received: from xanadu.home ([74.56.106.175]) by VL-MO-MR002.ip.videotron.ca (Sun Java System Messaging Server 6.2-2.05 (built Apr 28 2005)) with ESMTP id <0JNX00B2YOFE7900@VL-MO-MR002.ip.videotron.ca> for git@vger.kernel.org; Thu, 06 Sep 2007 02:23:38 -0400 (EDT) In-reply-to: <85ps0wfh8h.fsf@lola.goethe.zz> X-X-Sender: nico@xanadu.home Sender: git-owner@vger.kernel.org Precedence: bulk X-Mailing-List: git@vger.kernel.org Archived-At: On Thu, 6 Sep 2007, David Kastrup wrote: > Nicolas Pitre writes: > > > this is still rough, hence it is disabled by default. You need to compile > > with "make THREADED_DELTA_SEARCH=1 ..." at the moment. > > > > Threading is done on different portions of the object list to be > > deltified. This is currently done by spliting the list into n parts and > > then a thread is spawned for each of them. A better method would consist > > of spliting the list into more smaller parts and have the n threads > > pick the next part available. > > In my experience, the worst performance hit happens when the real > memory is exhausted and things start paging. Threading on different > portions of the object list is going to exacerbate the problem in the > areas where it hits worst. Just don't use it if you don't have 1) a SMP machine and 2) enough ram. Threading will be enabled with a command line argument at some point. Nicolas