From patchwork Fri Apr 22 06:35:07 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fam Zheng X-Patchwork-Id: 8906161 Return-Path: X-Original-To: patchwork-qemu-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 982CD9F1D3 for ; Fri, 22 Apr 2016 06:38:20 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 14D892025A for ; Fri, 22 Apr 2016 06:38:20 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6AD9020254 for ; Fri, 22 Apr 2016 06:38:19 +0000 (UTC) Received: from localhost ([::1]:55340 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1atUjK-0007hy-Mb for patchwork-qemu-devel@patchwork.kernel.org; Fri, 22 Apr 2016 02:38:18 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46576) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1atUgP-0001yv-Pg for qemu-devel@nongnu.org; Fri, 22 Apr 2016 02:35:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1atUgO-0000Wu-VI for qemu-devel@nongnu.org; Fri, 22 Apr 2016 02:35:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45365) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1atUgM-0000WN-Ik; Fri, 22 Apr 2016 02:35:14 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 3C3A181F03; Fri, 22 Apr 2016 06:35:14 +0000 (UTC) Received: from ad.usersys.redhat.com (dhcp-15-133.nay.redhat.com [10.66.15.133]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u3M6Z3cV014569; Fri, 22 Apr 2016 02:35:11 -0400 From: Fam Zheng To: qemu-devel@nongnu.org Date: Fri, 22 Apr 2016 14:35:07 +0800 Message-Id: <1461306907-2837-4-git-send-email-famz@redhat.com> In-Reply-To: <1461306907-2837-1-git-send-email-famz@redhat.com> References: <1461306907-2837-1-git-send-email-famz@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH for-2.6 3/3] block: Update comment of bdrv_drained_begin X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , qemu-block@nongnu.org, Jeff Cody , Max Reitz , stefanha@redhat.com, pbonzini@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The limitation should be documented. Removing it is a post 2.6 material. Signed-off-by: Fam Zheng --- include/block/block.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/include/block/block.h b/include/block/block.h index 3a73137..bb67652 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -530,6 +530,11 @@ void bdrv_flush_io_queue(BlockDriverState *bs); * this doesn't block timers or coroutines from submitting more requests, which * means block_job_pause is still necessary. * + * for now this only affacts the aio event loops (namely the data-plane + * iothreads and nested aio_poll() calls in block layer). Specifically, the + * main loop can still dispatch external events, even after bdrv_drained_begin + * is called. + * * This function can be recursive. */ void bdrv_drained_begin(BlockDriverState *bs);