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 CAE14C77B7E for ; Tue, 2 May 2023 16:22:32 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ptskx-0007Ff-Tq; Tue, 02 May 2023 12:21:35 -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 1ptskv-0007ER-G6 for qemu-devel@nongnu.org; Tue, 02 May 2023 12:21:33 -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 1ptskt-0006kn-Pf for qemu-devel@nongnu.org; Tue, 02 May 2023 12:21:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1683044490; 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=veAM1yxiNJOFHsx6/inor+jTVAWMkCyEti4maPSbfwU=; b=GvWuG76/BJfvvqcyPpvdY8HQIqsHpKQA6WpfN4zl2+PIrpmohDt91R1+c3lM4Mqo3gIDoQ fqaioTkvkf0HQG9S1tmccAfOVOEmHTaAxrNtsf2Ip3pA8bxTPYdTv0n6Y4BEEUG60kBi+s KbUpCLAa9NDf+mC2CamMTqBaGc2bUSM= 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-248-XFbx3vdZP5Ky0DHbFh4gXA-1; Tue, 02 May 2023 12:21:28 -0400 X-MC-Unique: XFbx3vdZP5Ky0DHbFh4gXA-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id C753C2807D63; Tue, 2 May 2023 16:21:25 +0000 (UTC) Received: from redhat.com (unknown [10.39.193.211]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E2BA563F4A; Tue, 2 May 2023 16:21:21 +0000 (UTC) Date: Tue, 2 May 2023 18:21:20 +0200 From: Kevin Wolf To: Stefan Hajnoczi Cc: qemu-devel@nongnu.org, Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= , Juan Quintela , Julia Suvorova , xen-devel@lists.xenproject.org, eesposit@redhat.com, Richard Henderson , Fam Zheng , "Michael S. Tsirkin" , Coiby Xu , David Woodhouse , Marcel Apfelbaum , Peter Lieven , Paul Durrant , "Richard W.M. Jones" , qemu-block@nongnu.org, Stefano Garzarella , Anthony Perard , Stefan Weil , Xie Yongji , Paolo Bonzini , Aarushi Mehta , Philippe =?iso-8859-1?Q?Mathieu-Daud=E9?= , Eduardo Habkost , Stefano Stabellini , Hanna Reitz , Ronnie Sahlberg Subject: Re: [PATCH v4 10/20] block: drain from main loop thread in bdrv_co_yield_to_drain() Message-ID: References: <20230425172716.1033562-1-stefanha@redhat.com> <20230425172716.1033562-11-stefanha@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230425172716.1033562-11-stefanha@redhat.com> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 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: -22 X-Spam_score: -2.3 X-Spam_bar: -- X-Spam_report: (-2.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.171, 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, T_SCC_BODY_TEXT_LINE=-0.01 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 25.04.2023 um 19:27 hat Stefan Hajnoczi geschrieben: > For simplicity, always run BlockDevOps .drained_begin/end/poll() > callbacks in the main loop thread. This makes it easier to implement the > callbacks and avoids extra locks. > > Move the function pointer declarations from the I/O Code section to the > Global State section in block-backend-common.h. > > Signed-off-by: Stefan Hajnoczi If we're updating function pointers, we should probably update them in BdrvChildClass and BlockDriver, too. This means that a non-coroutine caller can't run in an iothread, not even the home iothread of the BlockDriverState. (I'm not sure if it was allowed previously. I don't think we're actually doing this, but in theory it could have worked.) Maybe put a GLOBAL_STATE_CODE() after handling the bdrv_co_yield_to_drain() case? Or would that look too odd? IO_OR_GS_CODE(); if (qemu_in_coroutine()) { bdrv_co_yield_to_drain(bs, true, parent, poll); return; } GLOBAL_STATE_CODE(); Kevin