From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff King Subject: Re: Long clone time after "done." Date: Thu, 8 Nov 2012 17:33:19 -0500 Message-ID: <20121108223319.GA11734@sigill.intra.peff.net> References: <20121108155607.GD15560@sigill.intra.peff.net> <20121108203332.GQ15560@sigill.intra.peff.net> <20121108221128.GA11186@sigill.intra.peff.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: git@vger.kernel.org To: Uri Moszkowicz X-From: git-owner@vger.kernel.org Thu Nov 08 23:33:37 2012 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 1TWafI-0007Fo-KR for gcvg-git-2@plane.gmane.org; Thu, 08 Nov 2012 23:33:36 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756665Ab2KHWdX (ORCPT ); Thu, 8 Nov 2012 17:33:23 -0500 Received: from 75-15-5-89.uvs.iplsin.sbcglobal.net ([75.15.5.89]:36792 "EHLO peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756631Ab2KHWdX (ORCPT ); Thu, 8 Nov 2012 17:33:23 -0500 Received: (qmail 1473 invoked by uid 107); 8 Nov 2012 22:34:09 -0000 Received: from sigill.intra.peff.net (HELO sigill.intra.peff.net) (10.0.0.7) (smtp-auth username relayok, mechanism cram-md5) by peff.net (qpsmtpd/0.84) with ESMTPA; Thu, 08 Nov 2012 17:34:09 -0500 Received: by sigill.intra.peff.net (sSMTP sendmail emulation); Thu, 08 Nov 2012 17:33:19 -0500 Content-Disposition: inline In-Reply-To: Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: On Thu, Nov 08, 2012 at 04:16:59PM -0600, Uri Moszkowicz wrote: > I ran "git cat-file commit some-tag" for every tag. They seem to be > roughly uniformly distributed between 0s and 2s and about 2/3 of the > time seems to be system. My disk is mounted over NFS so I tried on the > local disk and it didn't make a difference. > > I have only one 1.97GB pack. I ran "git gc --aggressive" before. Ah. NFS. That is almost certainly the source of the problem. Git will aggressively mmap. I would not be surprised to find that RHEL4's NFS implementation is not particularly fast at mmap-ing 2G files, and is spending a bunch of time in the kernel servicing the requests. Aside from upgrading your OS or getting off of NFS, I don't have a lot of advice. The performance characteristics you are seeing are so grossly off of what is normal that using git is probably going to be painful. Your 2s cat-files should be more like .002s. I don't think there's anything for git to fix here. You could try building with NO_MMAP, which will emulate it with pread. That might fare better under your NFS implementation. Or it might be just as bad. -Peff