From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932359AbVHaEyM (ORCPT ); Wed, 31 Aug 2005 00:54:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751427AbVHaEyM (ORCPT ); Wed, 31 Aug 2005 00:54:12 -0400 Received: from omx2-ext.sgi.com ([192.48.171.19]:32445 "EHLO omx2.sgi.com") by vger.kernel.org with ESMTP id S1751248AbVHaEyM (ORCPT ); Wed, 31 Aug 2005 00:54:12 -0400 Date: Wed, 31 Aug 2005 14:53:05 +1000 From: Nathan Scott To: Tom Zanussi Cc: Jens Axboe , Linux Kernel Subject: Re: [PATCH] blk queue io tracing support Message-ID: <20050831145305.B4434621@wobbly.melbourne.sgi.com> References: <20050823123235.GG16461@suse.de> <20050824010346.GA1021@frodo> <20050824070809.GA27956@suse.de> <20050824171931.H4209301@wobbly.melbourne.sgi.com> <20050824072501.GA27992@suse.de> <20050824092838.GB28272@suse.de> <20050830234823.GF780@frodo> <20050830235824.GG780@frodo> <17173.12216.263860.76176@tut.ibm.com> <20050831143309.A4434621@wobbly.melbourne.sgi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <20050831143309.A4434621@wobbly.melbourne.sgi.com>; from nathans@sgi.com on Wed, Aug 31, 2005 at 02:33:10PM +1000 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 31, 2005 at 02:33:10PM +1000, Nathan Scott wrote: > ... > On an unrelated note, are there any known issues with using epoll > on relayfs file descriptors? I'm having a few troubles, and just > wondering if its me doing something silly, or if its known to not > work...? Symptoms of the problem are epoll continually reaching > its timeout with no modified fds found (when I know the inode has > modified trace buffers attached) ... Actually, poll(2) seems to have the same behaviour with a simpler test case (i.e. no epoll, & with just one fd being polled) - if I read(2) from it every few thousand usec (using the blktrace tool) it sees new data, but if I poll, it never reports the descriptor as changed (this is a 2.6.13 kernel with the relayfs patches from -mm patched into it and Jens' blktrace patch generating the data that I'm attempting to poll). cheers. -- Nathan