From patchwork Wed Sep 9 15:11:47 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 305793 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8DB8FC433E2 for ; Wed, 9 Sep 2020 15:17:27 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2F94B22272 for ; Wed, 9 Sep 2020 15:17:27 +0000 (UTC) Authentication-Results: mail.kernel.org; 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Wed, 9 Sep 2020 15:12:21 +0000 (UTC) Received: from linux.fritz.box.com (ovpn-113-221.ams2.redhat.com [10.36.113.221]) by smtp.corp.redhat.com (Postfix) with ESMTP id DBF9860C87; Wed, 9 Sep 2020 15:12:19 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Subject: [PATCH v7 11/13] util/async: Add aio_co_reschedule_self() Date: Wed, 9 Sep 2020 17:11:47 +0200 Message-Id: <20200909151149.490589-12-kwolf@redhat.com> In-Reply-To: <20200909151149.490589-1-kwolf@redhat.com> References: <20200909151149.490589-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=kwolf@redhat.com X-Mimecast-Spam-Score: 0.001 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=207.211.31.120; envelope-from=kwolf@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/09 03:05:47 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] 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_H2=-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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, qemu-devel@nongnu.org, armbru@redhat.com, marcandre.lureau@gmail.com, stefanha@redhat.com, dgilbert@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Add a function that can be used to move the currently running coroutine to a different AioContext (and therefore potentially a different thread). Signed-off-by: Kevin Wolf Reviewed-by: Stefan Hajnoczi --- include/block/aio.h | 10 ++++++++++ util/async.c | 30 ++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+) diff --git a/include/block/aio.h b/include/block/aio.h index b2f703fa3f..c37617b404 100644 --- a/include/block/aio.h +++ b/include/block/aio.h @@ -17,6 +17,7 @@ #ifdef CONFIG_LINUX_IO_URING #include #endif +#include "qemu/coroutine.h" #include "qemu/queue.h" #include "qemu/event_notifier.h" #include "qemu/thread.h" @@ -654,6 +655,15 @@ static inline bool aio_node_check(AioContext *ctx, bool is_external) */ void aio_co_schedule(AioContext *ctx, struct Coroutine *co); +/** + * aio_co_reschedule_self: + * @new_ctx: the new context + * + * Move the currently running coroutine to new_ctx. If the coroutine is already + * running in new_ctx, do nothing. + */ +void coroutine_fn aio_co_reschedule_self(AioContext *new_ctx); + /** * aio_co_wake: * @co: the coroutine diff --git a/util/async.c b/util/async.c index 4266745dee..a609e18693 100644 --- a/util/async.c +++ b/util/async.c @@ -569,6 +569,36 @@ void aio_co_schedule(AioContext *ctx, Coroutine *co) aio_context_unref(ctx); } +typedef struct AioCoRescheduleSelf { + Coroutine *co; + AioContext *new_ctx; +} AioCoRescheduleSelf; + +static void aio_co_reschedule_self_bh(void *opaque) +{ + AioCoRescheduleSelf *data = opaque; + aio_co_schedule(data->new_ctx, data->co); +} + +void coroutine_fn aio_co_reschedule_self(AioContext *new_ctx) +{ + AioContext *old_ctx = qemu_get_current_aio_context(); + + if (old_ctx != new_ctx) { + AioCoRescheduleSelf data = { + .co = qemu_coroutine_self(), + .new_ctx = new_ctx, + }; + /* + * We can't directly schedule the coroutine in the target context + * because this would be racy: The other thread could try to enter the + * coroutine before it has yielded in this one. + */ + aio_bh_schedule_oneshot(old_ctx, aio_co_reschedule_self_bh, &data); + qemu_coroutine_yield(); + } +} + void aio_co_wake(struct Coroutine *co) { AioContext *ctx;