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 7038CC4332F for ; Mon, 12 Dec 2022 15:58:11 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1p4lBL-0006CM-5x; Mon, 12 Dec 2022 10:57:31 -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 1p4lB8-00067G-VG for qemu-devel@nongnu.org; Mon, 12 Dec 2022 10:57:19 -0500 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 1p4lB7-00043Z-BO for qemu-devel@nongnu.org; Mon, 12 Dec 2022 10:57:18 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1670860635; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=yHnngiz4YfX3xVJTzbV4IBxZqnZ9v5ug6Rk7KENmTto=; b=GapGcgAoWqUjXBhV60aiIHFQTRCyXzTEIK0LXtBpUx6+acba+OWiX+CWLpdo5Q2WZJTtEp CKhzdYK/94GQ+bLPlDJAVyYEzqm2bgORTxwbLy1DXI0Sgb/4dfaty2z5+ZpKKGAiWQyNju U7b8A73Y5k86G5DlzG0r8w+YCHrOTYk= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-650-AracAQ9qNO-A8dIQBH1XtQ-1; Mon, 12 Dec 2022 10:57:12 -0500 X-MC-Unique: AracAQ9qNO-A8dIQBH1XtQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 37AE438123A6; Mon, 12 Dec 2022 15:57:12 +0000 (UTC) Received: from redhat.com (unknown [10.39.194.243]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 8A657C15BA0; Mon, 12 Dec 2022 15:57:10 +0000 (UTC) Date: Mon, 12 Dec 2022 16:57:07 +0100 From: Kevin Wolf To: Paolo Bonzini Cc: qemu-block@nongnu.org, eesposit@redhat.com, stefanha@redhat.com, hreitz@redhat.com, vsementsov@yandex-team.ru, qemu-devel@nongnu.org Subject: Re: [PATCH v2 14/15] block: Don't poll in bdrv_replace_child_noperm() Message-ID: References: <20221118174110.55183-1-kwolf@redhat.com> <20221118174110.55183-15-kwolf@redhat.com> <30eec378-779a-26ca-42f3-a7980a647ad7@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <30eec378-779a-26ca-42f3-a7980a647ad7@redhat.com> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Received-SPF: pass client-ip=170.10.133.124; envelope-from=kwolf@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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Am 09.12.2022 um 17:53 hat Paolo Bonzini geschrieben: > On 11/18/22 18:41, Kevin Wolf wrote: > > In order to make sure that bdrv_replace_child_noperm() doesn't have to > > poll any more, get rid of the bdrv_parent_drained_begin_single() call. > > > > This is possible now because we can require that the parent is already > > drained through the child in question when the function is called and we > > don't call the parent drain callbacks more than once. > > > > The additional drain calls needed in callers cause the test case to run > > its code in the drain handler too early (bdrv_attach_child() drains > > now), so modify it to only enable the code after the test setup has > > completed. > > > > Signed-off-by: Kevin Wolf > > I hate to bear bad news, but this breaks the Windows builds on github > (msys-32bit, msys-64bit) with an obscure but 100% reproducible > > 51/88 qemu:unit / test-bdrv-drain ERROR 1.30s (exit status > 3221225477 or signal 3221225349 SIGinvalid) > > The exit status is 0xC0000005 aka a Windows SIGSEGV. With some luck it > could be reproducible with Wine (but no gdb). I can reproduce it with mingw+wine (and actually gdb! Still a somewhat limited debugging environment, but not as bad as I imagined.) I looks to me like this is a problem with the test case rather than the change per se. It seems to be fixed with this patch that is already posted as part of the next series: [PATCH 09/18] test-bdrv-drain: Fix incorrrect drain assumptions https://lists.gnu.org/archive/html/qemu-block/2022-12/msg00165.html Kevin