From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jon Smirl" Subject: Re: performance on repack Date: Wed, 15 Aug 2007 14:38:15 -0400 Message-ID: <9e4733910708151138x2b267dc6w27c1bc8d948e5633@mail.gmail.com> References: <9e4733910708111412t48c1beaahfbaa2c68a02f64f1@mail.gmail.com> <20070812103338.GA7763@auto.tuwien.ac.at> <9e4733910708120649g5a5e0f48pa71bd983f2bc2945@mail.gmail.com> <20070814031236.GC27913@spearce.org> <20070815053231.GJ27913@spearce.org> <9e4733910708150808x39241071j1a4012f16cd26ef8@mail.gmail.com> <20070815171152.GA15155@auto.tuwien.ac.at> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: "Shawn O. Pearce" , "Nicolas Pitre" , "Git Mailing List" To: "Martin Koegler" X-From: git-owner@vger.kernel.org Wed Aug 15 20:38:31 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 1ILNl9-0006Gx-SR for gcvg-git@gmane.org; Wed, 15 Aug 2007 20:38:24 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933973AbXHOSiS (ORCPT ); Wed, 15 Aug 2007 14:38:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933723AbXHOSiS (ORCPT ); Wed, 15 Aug 2007 14:38:18 -0400 Received: from wa-out-1112.google.com ([209.85.146.176]:32126 "EHLO wa-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933598AbXHOSiQ (ORCPT ); Wed, 15 Aug 2007 14:38:16 -0400 Received: by wa-out-1112.google.com with SMTP id v27so10181wah for ; Wed, 15 Aug 2007 11:38:16 -0700 (PDT) DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=i4XMMeIdZSSSBRwqBTG55kqTwhA5K4BOFEcEZDV2Ep75TlDco7hiYEQtc69pa57o9mSVH2N1hmmX5bzctih3qAsQ9BOfqp1P13c36JS4dON0jWPer0UnKXYEVnooodKSF/nqu33JkqQf/0CfHwlcR1O7f84lpwzoDyEMdsjbbvQ= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=OEYydqyPlTdbicfX7O6S8/7w85qbJ4mOVm/KrYXnjmkkMSf3V0iF07JAwYuMJ1xM3OQT9JS9a8LhulEpx6d25MiW3hxfUjDXclIoz4VxOzP+EPBzhwnmpcCGyWnOqELhOzvqrpBf6vL0v88b7ghUPz/mwUvNP2//XOopnKUBJSY= Received: by 10.115.79.1 with SMTP id g1mr914133wal.1187203095731; Wed, 15 Aug 2007 11:38:15 -0700 (PDT) Received: by 10.114.195.11 with HTTP; Wed, 15 Aug 2007 11:38:15 -0700 (PDT) In-Reply-To: <20070815171152.GA15155@auto.tuwien.ac.at> Content-Disposition: inline Sender: git-owner@vger.kernel.org Precedence: bulk X-Mailing-List: git@vger.kernel.org Archived-At: On 8/15/07, Martin Koegler wrote: > git-pack-objects knows the order, in which it will use the objects. A > seperate thread could pre-read the next object and wait until the main > thread starts processing it. After the read is complete, another > thread could start computing the delta index. The hope is that the new adaptive read ahead code in the kernel will get this right and you won't need the second thread. Letting the kernel handle the read ahead will dynamically scale as other demands are made on the host. There's effectively only one read ahead cache in the system, only the kernel really knows how to divide it up between competing apps. -- Jon Smirl jonsmirl@gmail.com