From nobody Tue Feb 10 07:20:07 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1527615637670593.5218252890606; Tue, 29 May 2018 10:40:37 -0700 (PDT) Received: from localhost ([::1]:34209 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fNibs-0001lF-RT for importer@patchew.org; Tue, 29 May 2018 13:40:36 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58422) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fNiKV-00058n-Uq for qemu-devel@nongnu.org; Tue, 29 May 2018 13:22:41 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fNiKU-0001tw-VH for qemu-devel@nongnu.org; Tue, 29 May 2018 13:22:39 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:53726 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fNiKS-0001sB-Oh; Tue, 29 May 2018 13:22:36 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 681B9BD9E; Tue, 29 May 2018 17:22:36 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-116-193.ams2.redhat.com [10.36.116.193]) by smtp.corp.redhat.com (Postfix) with ESMTP id 16859111762D; Tue, 29 May 2018 17:22:34 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Date: Tue, 29 May 2018 19:21:52 +0200 Message-Id: <20180529172156.29311-17-kwolf@redhat.com> In-Reply-To: <20180529172156.29311-1-kwolf@redhat.com> References: <20180529172156.29311-1-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Tue, 29 May 2018 17:22:36 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Tue, 29 May 2018 17:22:36 +0000 (UTC) for IP:'10.11.54.3' DOMAIN:'int-mx03.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'kwolf@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH v2 16/20] block: Allow AIO_WAIT_WHILE with NULL ctx 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, famz@redhat.com, qemu-devel@nongnu.org, mreitz@redhat.com, stefanha@redhat.com, pbonzini@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" bdrv_drain_all() wants to have a single polling loop for draining the in-flight requests of all nodes. This means that the AIO_WAIT_WHILE() condition relies on activity in multiple AioContexts, which is polled from the mainloop context. We must therefore call AIO_WAIT_WHILE() from the mainloop thread and use the AioWait notification mechanism. Just randomly picking the AioContext of any non-mainloop thread would work, but instead of bothering to find such a context in the caller, we can just as well accept NULL for ctx. Signed-off-by: Kevin Wolf --- include/block/aio-wait.h | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/include/block/aio-wait.h b/include/block/aio-wait.h index 783d3678dd..c85a62f798 100644 --- a/include/block/aio-wait.h +++ b/include/block/aio-wait.h @@ -57,7 +57,8 @@ typedef struct { /** * AIO_WAIT_WHILE: * @wait: the aio wait object - * @ctx: the aio context + * @ctx: the aio context, or NULL if multiple aio contexts (for which the + * caller does not hold a lock) are involved in the polling conditio= n. * @cond: wait while this conditional expression is true * * Wait while a condition is true. Use this to implement synchronous @@ -75,7 +76,7 @@ typedef struct { bool waited_ =3D false; \ AioWait *wait_ =3D (wait); \ AioContext *ctx_ =3D (ctx); \ - if (in_aio_context_home_thread(ctx_)) { \ + if (ctx_ && in_aio_context_home_thread(ctx_)) { \ while ((cond)) { \ aio_poll(ctx_, true); \ waited_ =3D true; \ @@ -86,9 +87,13 @@ typedef struct { /* Increment wait_->num_waiters before evaluating cond. */ \ atomic_inc(&wait_->num_waiters); \ while ((cond)) { \ - aio_context_release(ctx_); \ + if (ctx_) { \ + aio_context_release(ctx_); \ + } \ aio_poll(qemu_get_aio_context(), true); \ - aio_context_acquire(ctx_); \ + if (ctx_) { \ + aio_context_acquire(ctx_); \ + } \ waited_ =3D true; \ } \ atomic_dec(&wait_->num_waiters); \ --=20 2.13.6