Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422982Ab2JaRwa (ORCPT ); Wed, 31 Oct 2012 13:52:30 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:53906 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759382Ab2JaRw1 (ORCPT ); Wed, 31 Oct 2012 13:52:27 -0400 Date: Wed, 31 Oct 2012 18:52:26 +0100 From: Pavel Machek To: Ingo Molnar Cc: David Ahern , git@vger.kernel.org, Arnaldo Carvalho de Melo , linux-kernel@vger.kernel.org, Andrew Vagin , Borislav Petkov , David Howells , Frederic Weisbecker , Jiri Olsa , Namhyung Kim , Paul Mackerras , Peter Zijlstra , Stephane Eranian , Steven Rostedt , arnaldo.melo@gmail.com, Arnaldo Carvalho de Melo Subject: Re: 'git describe' is very slow on development trees with lots of commits Message-ID: <20121031175226.GB20660@elf.ucw.cz> References: <1351261913-28250-1-git-send-email-acme@infradead.org> <20121026145451.GA14379@gmail.com> <508AA709.7010202@gmail.com> <20121027133352.GB30001@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20121027133352.GB30001@gmail.com> X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1363 Lines: 40 Hi! > (Cc:-ed the Git development list.) > > * David Ahern wrote: > > > PERF-VERSION-GEN and specifically the git commands are the > > cause of more delay than the config checks, especially when > > doing the build in a VM with the kernel source on an NFS > > mount. > > Yes, I have noticed that too. .... > The cost on this pretty fast machine is about 1 msecs per commit > - which adds up to about 2.5 seconds during much of the > development cycle. Well... I noticed my builds when little changed are very slow... and it was due to the computation of version string. Ouch. pavel@amd:~/mainline-altera/linux$ time git describe fixes-for-linus-506-g71ca8691 0.68user 0.22system 27.82 (0m27.820s) elapsed 3.26%CPU pavel@amd:~/mainline-altera/linux$ (Cached it is more reasonable 3 seconds, but it keeps going out of cache all the time. Uncached clean build is 3 minutes, cached is 9 seconds + time to do git describe). Thikpad X60. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/