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 4939AC7EE2D for ; Fri, 3 Mar 2023 15:53:03 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pY7hv-0000TR-2B; Fri, 03 Mar 2023 10:52:31 -0500 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 1pY7hu-0000T2-5W for qemu-devel@nongnu.org; Fri, 03 Mar 2023 10:52:30 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pY7hs-000076-7J for qemu-devel@nongnu.org; Fri, 03 Mar 2023 10:52:29 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1677858747; 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=V56OvcOO190xigwRcsAkqjlWVfJeFI8bqr4paxWoiok=; b=fzS0LsqHAlGJWakDDreNHTAdQUa8EV9vaq30jCcizSoIz79ldPX84Iat5khW3E7jRruXeu J13kwIMAuQNyrQLqf2ixZMdGxZF2rUlorQCPrHpObrzALdHbr/AUNqjOMMnVFr0me4ksan 9wETaFuqBQFh94xgNnBOCuERQSxEZSc= 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-517-E_zzXPdUNBmBErgcv19FUg-1; Fri, 03 Mar 2023 10:52:21 -0500 X-MC-Unique: E_zzXPdUNBmBErgcv19FUg-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id C5B87885621; Fri, 3 Mar 2023 15:52:20 +0000 (UTC) Received: from redhat.com (unknown [10.33.36.53]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BB3FA492C14; Fri, 3 Mar 2023 15:52:18 +0000 (UTC) Date: Fri, 3 Mar 2023 15:52:15 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Thomas Huth Cc: qemu-devel@nongnu.org, Kevin Wolf , Hanna Reitz , qemu-block@nongnu.org, Paolo Bonzini , Vladimir Sementsov-Ogievskiy Subject: Re: [PATCH 0/5] iotests: make meson aware of individual I/O tests Message-ID: References: <20230302184606.418541-1-berrange@redhat.com> <44d571e7-05b6-b2a1-7eb7-44bf2912ec69@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/2.2.9 (2022-11-12) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Fri, Mar 03, 2023 at 04:49:36PM +0100, Thomas Huth wrote: > On 03/03/2023 14.06, Daniel P. Berrangé wrote: > > On Fri, Mar 03, 2023 at 10:45:40AM +0000, Daniel P. Berrangé wrote: > > > On Fri, Mar 03, 2023 at 09:30:39AM +0100, Thomas Huth wrote: > > > > On 02/03/2023 19.46, Daniel P. Berrangé wrote: > > > > 3) When I tried this last year, I had a weird problem that > > > > the terminal sometimes gets messed up ... I wasn't able > > > > to track it down back then - could you check by running > > > > "make check-block" many times (>10 times) to see whether > > > > it happens with your series or not? > > > > > > I've just seen this - echo got disabled on my terminal. > > > > The problem is that testrunner.py script doing > > > > # We want to save current tty settings during test run, > > # since an aborting qemu call may leave things screwed up. > > @contextmanager > > def savetty() -> Iterator[None]: > > isterm = sys.stdin.isatty() > > if isterm: > > fd = sys.stdin.fileno() > > attr = termios.tcgetattr(fd) > > > > try: > > yield > > finally: > > if isterm: > > termios.tcsetattr(fd, termios.TCSADRAIN, attr) > > > > > > When invoking 'check' this wraps around execution of the entire > > 'check' script. IOW it saves/restores the terminal once. > > > > When we invoke 'check' in parallel it will save/restore the same > > terminal for each invokation. > > > > If the 'termios.tcgetattr' call runs at the same time as there is > > a QEMU running which has put the terminal in raw mode, then when > > 'check' exits it'll "restore" the terminal to raw mode. > > > > IOW, this savetty() logic is fundamentally unsafe when invoking > > 'check' in parallel. > > Hmm, couldn't we e.g. also simply skip this termios stuff when running with > "--tap" ? It actually turns out to be way simpler. We merely need to set stdin=subprocess.DEVNULL. There is no valid reason for the test cases to be reading for stdin, as that would block execution. By setting stdin==/dev/null, the isatty(0) checks will fail and thus QEMU won't mess with termios, and thus we don't need any save/restore dance either. 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 :|