Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750962Ab0HQVOG (ORCPT ); Tue, 17 Aug 2010 17:14:06 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:51850 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750705Ab0HQVOE convert rfc822-to-8bit (ORCPT ); Tue, 17 Aug 2010 17:14:04 -0400 MIME-Version: 1.0 In-Reply-To: References: <20100816.211218.189709876.davem@davemloft.net> From: Linus Torvalds Date: Tue, 17 Aug 2010 14:08:33 -0700 Message-ID: Subject: Re: tasks getting stuck on mmap_sem? To: Tony Luck Cc: David Miller , Michel Lespinasse , David Howells , Andrew Morton , linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1393 Lines: 31 On Tue, Aug 17, 2010 at 1:46 PM, Tony Luck wrote: > > Setting up for "git pull" would have been messy - but "git grep" is > multi-threaded in newer versions of git. So I've set a loop to keep > running "git grep" over and over. ?Load average is above 7, so > there must be some threading going on, even though I only see > one "git" process in "top(1)". ?Seems to be running fine so far. I'm not sure how page-fault intensive that 'git grep' thing is - I think it does mainly open/read/close on the files and probably doesn't take that many faults once malloc() has created the main heap. In contrast, the delta compute code (that david hit) is probably going to do a lot more page faults due to being way more data-intensive (many more mmap/munmap calls - it's how git tends to like to map git objects). So a more fault-intensive - and still threaded and all local - git load is likely to do something like git repack -adf and do it on something smaller than the whole kernel (git itself is probably a good test-case, and probably isn't that far off from a medium-sized kernel "pull" request). Linus -- 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/