From nobody Wed Dec 17 21:47:44 2025 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.zoho.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; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1498235208011526.991090560332; Fri, 23 Jun 2017 09:26:48 -0700 (PDT) Received: from localhost ([::1]:36236 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dORPy-0004pO-CG for importer@patchew.org; Fri, 23 Jun 2017 12:26:46 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59142) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dORLZ-0000LZ-Rz for qemu-devel@nongnu.org; Fri, 23 Jun 2017 12:22:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dORLY-0007SW-W1 for qemu-devel@nongnu.org; Fri, 23 Jun 2017 12:22:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44830) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dORLW-0007QS-Ho; Fri, 23 Jun 2017 12:22:10 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8A68A659A1; Fri, 23 Jun 2017 16:22:09 +0000 (UTC) Received: from noname.redhat.com (ovpn-117-196.ams2.redhat.com [10.36.117.196]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9F9236EC75; Fri, 23 Jun 2017 16:22:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 8A68A659A1 Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=kwolf@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 8A68A659A1 From: Kevin Wolf To: qemu-block@nongnu.org Date: Fri, 23 Jun 2017 18:21:03 +0200 Message-Id: <1498234919-27316-6-git-send-email-kwolf@redhat.com> In-Reply-To: <1498234919-27316-1-git-send-email-kwolf@redhat.com> References: <1498234919-27316-1-git-send-email-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Fri, 23 Jun 2017 16:22:09 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 05/61] block: use BDRV_POLL_WHILE() in bdrv_rw_vmstate() 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, qemu-devel@nongnu.org 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" From: Stefan Hajnoczi Calling aio_poll() directly may have been fine previously, but this is the future, man! The difference between an aio_poll() loop and BDRV_POLL_WHILE() is that BDRV_POLL_WHILE() releases the AioContext around aio_poll(). This allows the IOThread to run fd handlers or BHs to complete the request. Failure to release the AioContext causes deadlocks. Using BDRV_POLL_WHILE() partially fixes a 'savevm' hang with -object iothread. Signed-off-by: Stefan Hajnoczi Reviewed-by: Eric Blake Reviewed-by: Paolo Bonzini Signed-off-by: Kevin Wolf --- block/io.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/block/io.c b/block/io.c index 684ea46..e158ae0 100644 --- a/block/io.c +++ b/block/io.c @@ -2023,9 +2023,7 @@ bdrv_rw_vmstate(BlockDriverState *bs, QEMUIOVector *q= iov, int64_t pos, Coroutine *co =3D qemu_coroutine_create(bdrv_co_rw_vmstate_entry, = &data); =20 bdrv_coroutine_enter(bs, co); - while (data.ret =3D=3D -EINPROGRESS) { - aio_poll(bdrv_get_aio_context(bs), true); - } + BDRV_POLL_WHILE(bs, data.ret =3D=3D -EINPROGRESS); return data.ret; } } --=20 1.8.3.1