From patchwork Tue Aug 8 15:58:51 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 1818679 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) 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: legolas.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=CUFFbmvy; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4RKyZW2yW8z1yYl for ; Wed, 9 Aug 2023 02:00:19 +1000 (AEST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qTP7Y-00063L-DE; 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Tue, 08 Aug 2023 11:59:12 -0400 X-MC-Unique: njCPr4LdMz-rWMw_moMSgA-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 90902185A7A4; Tue, 8 Aug 2023 15:59:12 +0000 (UTC) Received: from localhost (unknown [10.39.193.72]) by smtp.corp.redhat.com (Postfix) with ESMTP id D1C6E492C14; Tue, 8 Aug 2023 15:59:11 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Kevin Wolf , Fam Zheng , qemu-block@nongnu.org, Hanna Reitz , Stefan Hajnoczi Subject: [PATCH 1/2] block: minimize bs->reqs_lock section in tracked_request_end() Date: Tue, 8 Aug 2023 11:58:51 -0400 Message-ID: <20230808155852.2745350-2-stefanha@redhat.com> In-Reply-To: <20230808155852.2745350-1-stefanha@redhat.com> References: <20230808155852.2745350-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 Received-SPF: pass client-ip=170.10.129.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Signed-off-by: Stefan Hajnoczi Reviewed-by: Eric Blake --- block/io.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/block/io.c b/block/io.c index 055fcf7438..85d5176256 100644 --- a/block/io.c +++ b/block/io.c @@ -593,8 +593,14 @@ static void coroutine_fn tracked_request_end(BdrvTrackedRequest *req) qemu_co_mutex_lock(&req->bs->reqs_lock); QLIST_REMOVE(req, list); + qemu_co_mutex_unlock(&req->bs->reqs_lock); + + /* + * At this point qemu_co_queue_wait(&req->wait_queue, ...) won't be called + * anymore because the request has been removed from the list, so it's safe + * to restart the queue outside reqs_lock to minimize the critical section. + */ qemu_co_queue_restart_all(&req->wait_queue); - qemu_co_mutex_unlock(&req->bs->reqs_lock); } /**