From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: S3 and sigwait (was Re: 2.6.13-rc3: swsusp works (TP 600X)) Date: Sat, 30 Jul 2005 12:30:34 +0200 Message-ID: <20050730103034.GC1942@elf.ucw.cz> References: <20050723003544.GC1988@elf.ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Sanjoy Mahajan Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, acpi-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-acpi@vger.kernel.org Hi! > >> One other glitch is that pdnsd (a nameserver caching daemon) has crashed > >> when the system wakes up from swsusp. It also happens when waking up > >> from S3, which was working with 2.6.11.4 although not with 2.6.13-rc3. > >> Many people have said mysql also does not suspend well. Is their use of > >> a named pipe or socket causing the problem? > > > No idea, strace? > > The upshot of stracing is in tthe Debian BTS > #319572. Paul Rombouts, an author of pdnsd, reproduced the strace > crash and found the problem: > > > Apparently strace causes sigwait to return EINTR, which is > > inconsistent with the documentation I could find on sigwait. > > Which is true. The sigwait man entry (Debian 'etch') says: > The !sigwait! function never returns an error. > > His patch (available in the BTS and included below) fixed the problem > of strace or S3 sleep crashing pdnsd. If you think it is a linux bug, can you produce small test case doing just the sigwait, and post it on l-k with big title "sigwait() breaks when straced, and on suspend"? That way it is going to get some attetion, and you'll get either documentation or kernel fixed. Pavel -- teflon -- maybe it is a trademark, but it should not be. ------------------------------------------------------- SF.Net email is sponsored by: Discover Easy Linux Migration Strategies from IBM. Find simple to follow Roadmaps, straightforward articles, informative Webcasts and more! Get everything you need to get up to speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click