From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50703) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UtbH8-0006ye-KN for qemu-devel@nongnu.org; Mon, 01 Jul 2013 06:24:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UtbH7-00036U-4b for qemu-devel@nongnu.org; Mon, 01 Jul 2013 06:24:02 -0400 Received: from mx1.redhat.com ([209.132.183.28]:13238) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UtbH6-00036N-UA for qemu-devel@nongnu.org; Mon, 01 Jul 2013 06:24:01 -0400 Date: Mon, 1 Jul 2013 12:23:53 +0200 From: Kevin Wolf Message-ID: <20130701102353.GB9000@dhcp-200-207.str.redhat.com> References: <1372528923-12354-1-git-send-email-alex@alex.org.uk> <1372528923-12354-2-git-send-email-alex@alex.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1372528923-12354-2-git-send-email-alex@alex.org.uk> Subject: Re: [Qemu-devel] [PATCH] Add delay option to blkdebug List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alex Bligh Cc: qemu-devel@nongnu.org, stefanha@redhat.com Am 29.06.2013 um 20:02 hat Alex Bligh geschrieben: > Add a delay option to blkdebug, allowing operations to be delayed by > a specifiable number of microseconds. Example configuration: > > [inject-error] > event = "read_aio" > delay = "200000" > > Signed-off-by: Alex Bligh "inject-error" doesn't really describe this well. Shouldn't we rather introduce a new section "[delay]" or something like that? I remember that I once tried something similar, but never submitted it. I think the reason was that using timers inside requests doesn't really work. It works as long as everything is indeed asynchronous, but bdrv_drain_all() or a loop waiting for a single request that tries to make progress with qemu_aio_wait() will simply hang because timers aren't processed in these nested event loops. Kevin