From nobody Tue Oct 28 02:08:43 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.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 Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1516115560762621.3561454337131; Tue, 16 Jan 2018 07:12:40 -0800 (PST) Received: from localhost ([::1]:39852 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ebSul-0006lf-UD for importer@patchew.org; Tue, 16 Jan 2018 10:12:39 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52384) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ebS96-0007pH-8F for qemu-devel@nongnu.org; Tue, 16 Jan 2018 09:23:25 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ebS95-0007ea-2P for qemu-devel@nongnu.org; Tue, 16 Jan 2018 09:23:24 -0500 Received: from mx1.redhat.com ([209.132.183.28]:34869) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ebS94-0007di-SK for qemu-devel@nongnu.org; Tue, 16 Jan 2018 09:23:22 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id ABFF5C052422 for ; Tue, 16 Jan 2018 14:23:21 +0000 (UTC) Received: from donizetti.redhat.com (ovpn-116-234.ams2.redhat.com [10.36.116.234]) by smtp.corp.redhat.com (Postfix) with ESMTP id E98345C8AF for ; Tue, 16 Jan 2018 14:23:19 +0000 (UTC) From: Paolo Bonzini To: qemu-devel@nongnu.org Date: Tue, 16 Jan 2018 15:23:14 +0100 Message-Id: <20180116142316.30486-3-pbonzini@redhat.com> In-Reply-To: <20180116142316.30486-1-pbonzini@redhat.com> References: <20180116142316.30486-1-pbonzini@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Tue, 16 Jan 2018 14:23:21 +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] [PATCH 2/4] coroutine-lock: convert CoQueue to use QemuLockable 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: , 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" There are cases in which a queued coroutine must be restarted from non-coroutine context (with qemu_co_enter_next). In this cases, qemu_co_enter_next also needs to be thread-safe, but it cannot use a CoMutex and so cannot qemu_co_queue_wait. Use QemuLockable so that the CoQueue can interchangeably use CoMutex or QemuMutex. Signed-off-by: Paolo Bonzini --- include/qemu/coroutine.h | 6 +++++- util/qemu-coroutine-lock.c | 12 +++++++----- 2 files changed, 12 insertions(+), 6 deletions(-) diff --git a/include/qemu/coroutine.h b/include/qemu/coroutine.h index 8a5129741c..1e5f0957e6 100644 --- a/include/qemu/coroutine.h +++ b/include/qemu/coroutine.h @@ -183,7 +183,9 @@ void qemu_co_queue_init(CoQueue *queue); * caller of the coroutine. The mutex is unlocked during the wait and * locked again afterwards. */ -void coroutine_fn qemu_co_queue_wait(CoQueue *queue, CoMutex *mutex); +#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 *lo= ck); =20 /** * Restarts the next coroutine in the CoQueue and removes it from the queu= e. @@ -271,4 +273,6 @@ void coroutine_fn qemu_co_sleep_ns(QEMUClockType type, = int64_t ns); */ void coroutine_fn yield_until_fd_readable(int fd); =20 +#include "qemu/lockable.h" + #endif /* QEMU_COROUTINE_H */ diff --git a/util/qemu-coroutine-lock.c b/util/qemu-coroutine-lock.c index 846ff9167f..2a66fc1467 100644 --- a/util/qemu-coroutine-lock.c +++ b/util/qemu-coroutine-lock.c @@ -40,13 +40,13 @@ void qemu_co_queue_init(CoQueue *queue) QSIMPLEQ_INIT(&queue->entries); } =20 -void coroutine_fn qemu_co_queue_wait(CoQueue *queue, CoMutex *mutex) +void coroutine_fn qemu_co_queue_wait_impl(CoQueue *queue, QemuLockable *lo= ck) { Coroutine *self =3D qemu_coroutine_self(); QSIMPLEQ_INSERT_TAIL(&queue->entries, self, co_queue_next); =20 - if (mutex) { - qemu_co_mutex_unlock(mutex); + if (lock) { + qemu_lockable_unlock(lock); } =20 /* There is no race condition here. Other threads will call @@ -60,9 +60,11 @@ void coroutine_fn qemu_co_queue_wait(CoQueue *queue, CoM= utex *mutex) /* TODO: OSv implements wait morphing here, where the wakeup * primitive automatically places the woken coroutine on the * mutex's queue. This avoids the thundering herd effect. + * This could be implemented for CoMutexes, but not really for + * other cases of QemuLockable. */ - if (mutex) { - qemu_co_mutex_lock(mutex); + if (lock) { + qemu_lockable_lock(lock); } } =20 --=20 2.14.3