From patchwork Tue Sep 27 19:34:20 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 1683504 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=BKhthOez; 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 4McVH66NY2z1yqD for ; Wed, 28 Sep 2022 05:36:18 +1000 (AEST) Received: from localhost ([::1]:36852 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1odGNM-0000MZ-Ox for incoming@patchwork.ozlabs.org; Tue, 27 Sep 2022 15:36:16 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:45432) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1odGLt-0008Gv-Jf for qemu-devel@nongnu.org; Tue, 27 Sep 2022 15:34:46 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:48404) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1odGLr-0004ah-RF for qemu-devel@nongnu.org; Tue, 27 Sep 2022 15:34:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1664307283; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=nZH926jePVfo9Jq+WbPxGtW5ubS1EygFordvFbCKPJM=; b=BKhthOezJ9Rmtt71lugZSa1xE6P5iwXVjSZYIur8JEe8dSCmJ+219pg+qCqBfSahYTWd5H uqNolib8uygmu/4s/cbyaulJlEsEFWRIvs1NuOEDWIklWgmw2acIR5jOZPdodNsaihdAH/ MbaXDxujiCILNRaQzQq5IKSgyZ43RiI= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-132-AyEpY82fNJKGlzTiQj0yKQ-1; Tue, 27 Sep 2022 15:34:39 -0400 X-MC-Unique: AyEpY82fNJKGlzTiQj0yKQ-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 5B7BE185A78F; Tue, 27 Sep 2022 19:34:38 +0000 (UTC) Received: from localhost (unknown [10.39.192.120]) by smtp.corp.redhat.com (Postfix) with ESMTP id 86E21492B04; Tue, 27 Sep 2022 19:34:37 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Yanan Wang , Kevin Wolf , Markus Armbruster , John Snow , "Denis V. Lunev" , Xie Changlong , Eric Blake , integration@gluster.org, David Hildenbrand , Wen Congyang , Laurent Vivier , "Richard W.M. Jones" , afaria@redhat.com, Fam Zheng , Thomas Huth , Hanna Reitz , Eduardo Habkost , Peter Xu , Raphael Norwitz , Stefan Hajnoczi , Marcel Apfelbaum , Vladimir Sementsov-Ogievskiy , =?utf-8?q?Philipp?= =?utf-8?q?e_Mathieu-Daud=C3=A9?= , Jeff Cody , qemu-block@nongnu.org, Paolo Bonzini , Richard Henderson , "Michael S. Tsirkin" , sgarzare@redhat.com Subject: [PATCH v5 01/12] coroutine: add flag to re-queue at front of CoQueue Date: Tue, 27 Sep 2022 15:34:20 -0400 Message-Id: <20220927193431.22302-2-stefanha@redhat.com> In-Reply-To: <20220927193431.22302-1-stefanha@redhat.com> References: <20220927193431.22302-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 Received-SPF: pass client-ip=170.10.133.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham 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" When a coroutine wakes up it may determine that it must re-queue. Normally coroutines are pushed onto the back of the CoQueue, but for fairness it may be necessary to push it onto the front of the CoQueue. Add a flag to specify that the coroutine should be pushed onto the front of the CoQueue. A later patch will use this to ensure fairness in the bounce buffer CoQueue used by the blkio BlockDriver. Signed-off-by: Stefan Hajnoczi --- include/qemu/coroutine.h | 15 +++++++++++++-- util/qemu-coroutine-lock.c | 9 +++++++-- 2 files changed, 20 insertions(+), 4 deletions(-) diff --git a/include/qemu/coroutine.h b/include/qemu/coroutine.h index 08c5bb3c76..3f418a67f6 100644 --- a/include/qemu/coroutine.h +++ b/include/qemu/coroutine.h @@ -198,14 +198,25 @@ typedef struct CoQueue { */ void qemu_co_queue_init(CoQueue *queue); +typedef enum { + /* + * Enqueue at front instead of back. Use this to re-queue a request when + * its wait condition is not satisfied after being woken up. + */ + CO_QUEUE_WAIT_FRONT = 0x1, +} CoQueueWaitFlags; + /** * Adds the current coroutine to the CoQueue and transfers control to the * caller of the coroutine. The mutex is unlocked during the wait and * locked again afterwards. */ #define qemu_co_queue_wait(queue, lock) \ - qemu_co_queue_wait_impl(queue, QEMU_MAKE_LOCKABLE(lock)) -void coroutine_fn qemu_co_queue_wait_impl(CoQueue *queue, QemuLockable *lock); + qemu_co_queue_wait_impl(queue, QEMU_MAKE_LOCKABLE(lock), 0) +#define qemu_co_queue_wait_flags(queue, lock, flags) \ + qemu_co_queue_wait_impl(queue, QEMU_MAKE_LOCKABLE(lock), (flags)) +void coroutine_fn qemu_co_queue_wait_impl(CoQueue *queue, QemuLockable *lock, + CoQueueWaitFlags flags); /** * Removes the next coroutine from the CoQueue, and queue it to run after diff --git a/util/qemu-coroutine-lock.c b/util/qemu-coroutine-lock.c index 9ad24ab1af..0516bd2ff3 100644 --- a/util/qemu-coroutine-lock.c +++ b/util/qemu-coroutine-lock.c @@ -39,10 +39,15 @@ void qemu_co_queue_init(CoQueue *queue) QSIMPLEQ_INIT(&queue->entries); } -void coroutine_fn qemu_co_queue_wait_impl(CoQueue *queue, QemuLockable *lock) +void coroutine_fn qemu_co_queue_wait_impl(CoQueue *queue, QemuLockable *lock, + CoQueueWaitFlags flags) { Coroutine *self = qemu_coroutine_self(); - QSIMPLEQ_INSERT_TAIL(&queue->entries, self, co_queue_next); + if (flags & CO_QUEUE_WAIT_FRONT) { + QSIMPLEQ_INSERT_HEAD(&queue->entries, self, co_queue_next); + } else { + QSIMPLEQ_INSERT_TAIL(&queue->entries, self, co_queue_next); + } if (lock) { qemu_lockable_unlock(lock);