From patchwork Thu Nov 16 16:36:14 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 10061473 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 15957604D3 for ; Thu, 16 Nov 2017 16:37:21 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 091512ABB3 for ; Thu, 16 Nov 2017 16:37:21 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 07AAD2ABE9; Thu, 16 Nov 2017 16:37:21 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 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.wl.linuxfoundation.org (Postfix) with ESMTPS id 9F8B42ABB3 for ; Thu, 16 Nov 2017 16:37:20 +0000 (UTC) Received: from localhost ([::1]:41693 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eFNAF-0002x8-UW for patchwork-qemu-devel@patchwork.kernel.org; Thu, 16 Nov 2017 11:37:19 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60165) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eFN9L-0002w4-9O for qemu-devel@nongnu.org; Thu, 16 Nov 2017 11:36:24 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eFN9H-00061A-UN for qemu-devel@nongnu.org; Thu, 16 Nov 2017 11:36:23 -0500 Received: from mx1.redhat.com ([209.132.183.28]:25966) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eFN9H-00060t-O5 for qemu-devel@nongnu.org; Thu, 16 Nov 2017 11:36:19 -0500 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 D6A97356FA; Thu, 16 Nov 2017 16:36:18 +0000 (UTC) Received: from localhost (ovpn-116-23.ams2.redhat.com [10.36.116.23]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7A02060F8A; Thu, 16 Nov 2017 16:36:18 +0000 (UTC) From: Stefan Hajnoczi To: Date: Thu, 16 Nov 2017 16:36:14 +0000 Message-Id: <20171116163614.24710-2-stefanha@redhat.com> In-Reply-To: <20171116163614.24710-1-stefanha@redhat.com> References: <20171116163614.24710-1-stefanha@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 [10.5.110.30]); Thu, 16 Nov 2017 16:36:18 +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 for-2.11 1/1] throttle-groups: forget timer and schedule next TGM on detach 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: Peter Maydell , Stefan Hajnoczi Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP tg->any_timer_armed[] must be cleared when detaching pending timers from the AioContext. Failure to do so leads to hung I/O because it looks like there are still timers pending when in fact they have been removed. Other ThrottleGroupMembers might have requests pending too so it's necessary to schedule the next TGM so it can set a timer. This patch fixes hung I/O when QEMU is launched with drives that are in the same throttling group: (guest)$ dd if=/dev/zero of=/dev/vdb oflag=direct bs=512 & (guest)$ dd if=/dev/zero of=/dev/vdc oflag=direct bs=512 & (qemu) stop (qemu) cont ...I/O is stuck... Signed-off-by: Stefan Hajnoczi Message-id: 20171116112150.27607-1-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi --- block/throttle-groups.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/block/throttle-groups.c b/block/throttle-groups.c index 2587f19ca3..f26bcb5eee 100644 --- a/block/throttle-groups.c +++ b/block/throttle-groups.c @@ -593,13 +593,25 @@ void throttle_group_attach_aio_context(ThrottleGroupMember *tgm, void throttle_group_detach_aio_context(ThrottleGroupMember *tgm) { + ThrottleGroup *tg = container_of(tgm->throttle_state, ThrottleGroup, ts); ThrottleTimers *tt = &tgm->throttle_timers; + int i; /* Requests must have been drained */ assert(tgm->pending_reqs[0] == 0 && tgm->pending_reqs[1] == 0); assert(qemu_co_queue_empty(&tgm->throttled_reqs[0])); assert(qemu_co_queue_empty(&tgm->throttled_reqs[1])); + /* Kick off next ThrottleGroupMember, if necessary */ + qemu_mutex_lock(&tg->lock); + for (i = 0; i < 2; i++) { + if (timer_pending(tt->timers[i])) { + tg->any_timer_armed[i] = false; + schedule_next_request(tgm, i); + } + } + qemu_mutex_unlock(&tg->lock); + throttle_timers_detach_aio_context(tt); tgm->aio_context = NULL; }