From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C3F55ECAAA1 for ; Thu, 27 Oct 2022 14:29:22 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oo3qT-0005Gr-Vu; Thu, 27 Oct 2022 10:26:58 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oo3qS-0004px-EO for qemu-devel@nongnu.org; Thu, 27 Oct 2022 10:26:56 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oo3qQ-0001YX-BJ for qemu-devel@nongnu.org; Thu, 27 Oct 2022 10:26:56 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1666880813; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BGKpeOk0czBUVXlYBifRnRP+/d8sZo14l0pyLUwBhao=; b=Voqfvd2gXpTuKo6uBtS8wyu6DMik798Jl2uiV9p37BmSS7uBlwIoGNGjz83n8u5FXr6bN3 L20yfxvQAiqplS6qfkZqawhfZKOXj+ZyH4yNiijD5VFeFdhKsXs5K0NL0MAVfg61HqKcWQ BlKsZs12bNNgLanRg6AQ095FkG/CpVM= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-8-Nl5YnBJrMfulzzydIMX5Iw-1; Thu, 27 Oct 2022 10:26:49 -0400 X-MC-Unique: Nl5YnBJrMfulzzydIMX5Iw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 5DA5087B2B7; Thu, 27 Oct 2022 14:26:44 +0000 (UTC) Received: from redhat.com (unknown [10.33.36.37]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6A8612028E98; Thu, 27 Oct 2022 14:26:41 +0000 (UTC) Date: Thu, 27 Oct 2022 15:26:38 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Alex =?utf-8?Q?Benn=C3=A9e?= Cc: Thomas Huth , Stefan Hajnoczi , =?utf-8?Q?Marc-Andr=C3=A9?= Lureau , Juan Quintela , qemu-devel@nongnu.org Subject: Re: [PATCH] tests: Create fifo for test-io-channel-command Message-ID: References: <20221025105520.3016-1-quintela@redhat.com> <87mt9k6owd.fsf@linaro.org> <875yg64kxp.fsf@linaro.org> <87h6zp1i4u.fsf@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <87h6zp1i4u.fsf@linaro.org> User-Agent: Mutt/2.2.7 (2022-08-07) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -25 X-Spam_score: -2.6 X-Spam_bar: -- X-Spam_report: (-2.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.515, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Sender: "Qemu-devel" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Thu, Oct 27, 2022 at 02:59:04PM +0100, Alex Bennée wrote: > > Thomas Huth writes: > > > On 26/10/2022 18.18, Alex Bennée wrote: > >> Daniel P. Berrangé writes: > >> > >>> CC'ing Marc-André as original author of the change > >>> > >>> On Tue, Oct 25, 2022 at 01:57:23PM +0100, Alex Bennée wrote: > >>>> > >>>> Juan Quintela writes: > >>>> > >>>>> Previous commit removed the creation of the fifo. Without it, I get > >>>>> random failure during tests with high load, please consider > >>>>> reintroduce it. > >>>>> > >>>>> My guess is that there is a race between the two socats when we leave > >>>>> them to create the channel, better return to the previous behavior. > >>>>> > >>>>> I can't reproduce the problem when I run ./test-io-channel-command > >>>>> test alone, I need to do the make check. And any (unrelated) change > >>>>> can make it dissapear. > >>>> > >>>> I was chasing a similar problem with this test although I don't see it > >>>> timeout while running (I don't think our unit tests time out). I'm > >>>> provisionally queuing this to testing/next unless anyone objects. > >>> > >>> It won't build on Win32 since that platform lacks mkfifo. > >>> > >>> The test normally works since socat will call mknod to create > >>> the fifo. > >>> > >>> I think the problem is that we have a race condition where the > >>> client socat runs before the server socat, and so won't see the > >>> fifo. This will be where high load triggers problems. > >> Ok I shall drop the patch from testing/next - we need a better > >> solution. > > > > Could we maybe at least revert the patch that introduced the problem? > > ... the failing test is annoying ... > > I'm trying to fix it now but I haven't been able to get one of the > socat's to not race with the other: My other thought was to run a socat first, with 'unlink-close=0' and make it exit immediately, simply to get the fifo created. I'm not sure how to make ti exit immediately though, with a guarantee that its had a chance to create the fifo. With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|