From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with ESMTP id 6DFFF6B004D for ; Thu, 6 Aug 2009 11:54:46 -0400 (EDT) Date: Thu, 6 Aug 2009 16:54:51 +0100 From: Mel Gorman Subject: Re: [PATCH 4/4] tracing, page-allocator: Add a postprocessing script for page-allocator-related ftrace events Message-ID: <20090806155451.GC6915@csn.ul.ie> References: <1249409546-6343-1-git-send-email-mel@csn.ul.ie> <1249409546-6343-5-git-send-email-mel@csn.ul.ie> <20090804112246.4e6d0ab1.akpm@linux-foundation.org> <4A787D84.2030207@redhat.com> <20090804121332.46df33a7.akpm@linux-foundation.org> <20090804204857.GA32092@csn.ul.ie> <1249484030.7512.42.camel@dhcp-100-19-198.bos.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <1249484030.7512.42.camel@dhcp-100-19-198.bos.redhat.com> Sender: owner-linux-mm@kvack.org To: Larry Woodman Cc: Andrew Morton , Rik van Riel , mingo@elte.hu, peterz@infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Wed, Aug 05, 2009 at 10:53:50AM -0400, Larry Woodman wrote: > On Tue, 2009-08-04 at 21:48 +0100, Mel Gorman wrote: > > > > > > > > Adding and deleting tracepoints, rebuilding and rebooting the kernel is > > obviously usable by developers but not a whole pile of use if > > recompiling the kernel is not an option or you're trying to debug a > > difficult-to-reproduce-but-is-happening-now type of problem. > > > > Of the CC list, I believe Larry Woodman has the most experience with > > these sort of problems in the field so I'm hoping he'll make some sort > > of comment. > > > > I am all for adding tracepoints that eliminate the need to locate a > problem, add debug code, rebuild, reboot and retest until the real > problem is found. > > Personally I have not seen as many problems in the page allocator as I > have in the page reclaim code thats why the majority of my tracepoints > were in vmscan.c I'd be surprised if you had, problems in page reclaim would be a lot more obvious for a start. The page allocator happened to be where I wanted tracepoints at the moment and I think the next patchset will act as a template for how to introduce tracepoints which can be repeated for the reclaim points. > However I do ACK this patch set because it provides > the opportunity to zoom into the page allocator dynamically without > needing to iterate through the cumbersome debug process. > Thanks. -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org