From patchwork Mon Feb 25 15:19:55 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 1047779 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 447QpQ3v81z9s6w for ; Tue, 26 Feb 2019 02:29:02 +1100 (AEDT) Received: from localhost ([127.0.0.1]:39095 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gyIBf-0005vG-B6 for incoming@patchwork.ozlabs.org; Mon, 25 Feb 2019 10:28:59 -0500 Received: from eggs.gnu.org ([209.51.188.92]:37270) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gyI4h-00009w-A8 for qemu-devel@nongnu.org; Mon, 25 Feb 2019 10:21:48 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gyI4b-0000pZ-3E for qemu-devel@nongnu.org; Mon, 25 Feb 2019 10:21:47 -0500 Received: from mx1.redhat.com ([209.132.183.28]:58212) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gyI4P-0000ic-RM; Mon, 25 Feb 2019 10:21:30 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C0751811D8; Mon, 25 Feb 2019 15:21:26 +0000 (UTC) Received: from linux.fritz.box.com (ovpn-117-243.ams2.redhat.com [10.36.117.243]) by smtp.corp.redhat.com (Postfix) with ESMTP id 10E385C221; Mon, 25 Feb 2019 15:21:24 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Date: Mon, 25 Feb 2019 16:19:55 +0100 Message-Id: <20190225152053.15976-14-kwolf@redhat.com> In-Reply-To: <20190225152053.15976-1-kwolf@redhat.com> References: <20190225152053.15976-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Mon, 25 Feb 2019 15:21:26 +0000 (UTC) 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] [PULL 13/71] io: Remove redundant read/write_coroutine assignments 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: kwolf@redhat.com, peter.maydell@linaro.org, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" qio_channel_yield() now updates ioc->read_write/coroutine and calls qio_channel_set_aio_fd_handlers(), so the code in the handlers has become redundant and can be removed. This does not make a difference in intermediate states because aio_co_wake() really enters the coroutine immediately here: These handlers are never run in coroutine context, and we're in the right AioContext because qio_channel_attach_aio_context() asserts that the handlers are inactive. To make these conditions more obvious, assert the right AioContext. Suggested-by: Paolo Bonzini Signed-off-by: Kevin Wolf --- io/channel.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/io/channel.c b/io/channel.c index 303376e08d..2a26c2a2c0 100644 --- a/io/channel.c +++ b/io/channel.c @@ -400,15 +400,14 @@ off_t qio_channel_io_seek(QIOChannel *ioc, } -static void qio_channel_set_aio_fd_handlers(QIOChannel *ioc); - static void qio_channel_restart_read(void *opaque) { QIOChannel *ioc = opaque; Coroutine *co = ioc->read_coroutine; - ioc->read_coroutine = NULL; - qio_channel_set_aio_fd_handlers(ioc); + /* Assert that aio_co_wake() reenters the coroutine directly */ + assert(qemu_get_current_aio_context() == + qemu_coroutine_get_aio_context(co)); aio_co_wake(co); } @@ -417,8 +416,9 @@ static void qio_channel_restart_write(void *opaque) QIOChannel *ioc = opaque; Coroutine *co = ioc->write_coroutine; - ioc->write_coroutine = NULL; - qio_channel_set_aio_fd_handlers(ioc); + /* Assert that aio_co_wake() reenters the coroutine directly */ + assert(qemu_get_current_aio_context() == + qemu_coroutine_get_aio_context(co)); aio_co_wake(co); }