Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758068Ab1COQDZ (ORCPT ); Tue, 15 Mar 2011 12:03:25 -0400 Received: from twin.jikos.cz ([89.185.236.188]:34650 "EHLO twin.jikos.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750843Ab1COQDY (ORCPT ); Tue, 15 Mar 2011 12:03:24 -0400 X-Greylist: delayed 2442 seconds by postgrey-1.27 at vger.kernel.org; Tue, 15 Mar 2011 12:03:24 EDT Date: Tue, 15 Mar 2011 16:22:22 +0100 From: David Sterba To: linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: adilger@dilger.ca Subject: Re: ext4 deep stack with mark_page_dirty reclaim Message-ID: <20110315152222.GW17108@twin.jikos.cz> Reply-To: dave@jikos.cz Mail-Followup-To: linux-kernel@vger.kernel.org, linux-mm@kvack.org, adilger@dilger.ca References: <20110314204627.GB8120@thunk.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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: 1404 Lines: 41 On Mon, Mar 14, 2011 at 07:25:10PM -0700, Andreas Dilger wrote: > Is there a script which you used to generate this stack trace to > function size mapping, or did you do it by hand? I've always wanted > such a script, but the tricky part is that there is so much garbage on > the stack that any automated stack parsing is almost useless. > Alternately, it would seem trivial to have the stack dumper print the > relative address of each symbol, and the delta from the previous > symbol... > > 240 schedule+0x25a > > 368 io_schedule+0x35 > > 32 get_request_wait+0xc6 from the callstack: ffff88007a704338 schedule+0x25a ffff88007a7044a8 io_schedule+0x35 ffff88007a7044c8 get_request_wait+0xc6 subtract the values and you get the ones Ted posted, eg. for get_request_wait: 0xffff88007a7044c8 - 0xffff88007a7044a8 = 32 There'se a script scripts/checkstack.pl which tries to determine stack usage from 'objdump -d' looking for the 'sub 0x123,%rsp' instruction and reporting the 0x123 as stack consumption. It does not give same results, for the get_request_wait: ffffffff81216205: 48 83 ec 68 sub $0x68,%rsp reported as 104. dave -- 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/