From patchwork Tue Apr 25 17:27:01 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 13223559 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B5E1AC77B7F for ; Tue, 25 Apr 2023 17:27:50 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.526176.817734 (Exim 4.92) (envelope-from ) id 1prMS4-0007mh-FL; Tue, 25 Apr 2023 17:27:40 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 526176.817734; Tue, 25 Apr 2023 17:27:40 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1prMS4-0007mY-Ae; Tue, 25 Apr 2023 17:27:40 +0000 Received: by outflank-mailman (input) for mailman id 526176; Tue, 25 Apr 2023 17:27:38 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1prMS2-0006fQ-GZ for xen-devel@lists.xenproject.org; Tue, 25 Apr 2023 17:27:38 +0000 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 78b37e55-e38e-11ed-b223-6b7b168915f2; Tue, 25 Apr 2023 19:27:37 +0200 (CEST) Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-668-sx8UeKvTNgSkYAJ4YHtjZQ-1; Tue, 25 Apr 2023 13:27:33 -0400 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 06A6128082AC; Tue, 25 Apr 2023 17:27:32 +0000 (UTC) Received: from localhost (unknown [10.39.193.242]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5EE9B492C13; Tue, 25 Apr 2023 17:27:31 +0000 (UTC) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 78b37e55-e38e-11ed-b223-6b7b168915f2 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1682443656; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=B3H8MiZnviPPfHHhNt1UwKF8b8RPyeQv8gQKbNPpxCA=; b=Oo9bBjzectlGtdKIB+P6y1Onka2xWwJDAvL6oj+QsDf44S5PJGiYCO4HVsTbmhySVnTMbn mECVXgQhzw0zZe3pnbaD9b0D6r/+Ln7UpoERLTKUPZr4yumLSvW1D0eKNMGxlhXy4j7kwR IwfWWwlXXsrFV2hQzyuoTeeJBfHRTfk= X-MC-Unique: sx8UeKvTNgSkYAJ4YHtjZQ-1 From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= , Juan Quintela , Julia Suvorova , Kevin Wolf , xen-devel@lists.xenproject.org, eesposit@redhat.com, Richard Henderson , Fam Zheng , "Michael S. Tsirkin" , Coiby Xu , David Woodhouse , Marcel Apfelbaum , Peter Lieven , Paul Durrant , Stefan Hajnoczi , "Richard W.M. Jones" , qemu-block@nongnu.org, Stefano Garzarella , Anthony Perard , Stefan Weil , Xie Yongji , Paolo Bonzini , Aarushi Mehta , =?utf-8?q?Philippe_Mathieu-Daud?= =?utf-8?q?=C3=A9?= , Eduardo Habkost , Stefano Stabellini , Hanna Reitz , Ronnie Sahlberg Subject: [PATCH v4 05/20] util/vhost-user-server: rename refcount to in_flight counter Date: Tue, 25 Apr 2023 13:27:01 -0400 Message-Id: <20230425172716.1033562-6-stefanha@redhat.com> In-Reply-To: <20230425172716.1033562-1-stefanha@redhat.com> References: <20230425172716.1033562-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 The VuServer object has a refcount field and ref/unref APIs. The name is confusing because it's actually an in-flight request counter instead of a refcount. Normally a refcount destroys the object upon reaching zero. The VuServer counter is used to wake up the vhost-user coroutine when there are no more requests. Avoid confusing by renaming refcount and ref/unref to in_flight and inc/dec. Reviewed-by: Paolo Bonzini Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Stefan Hajnoczi --- include/qemu/vhost-user-server.h | 6 +++--- block/export/vhost-user-blk-server.c | 11 +++++++---- util/vhost-user-server.c | 14 +++++++------- 3 files changed, 17 insertions(+), 14 deletions(-) diff --git a/include/qemu/vhost-user-server.h b/include/qemu/vhost-user-server.h index 25c72433ca..bc0ac9ddb6 100644 --- a/include/qemu/vhost-user-server.h +++ b/include/qemu/vhost-user-server.h @@ -41,7 +41,7 @@ typedef struct { const VuDevIface *vu_iface; /* Protected by ctx lock */ - unsigned int refcount; + unsigned int in_flight; bool wait_idle; VuDev vu_dev; QIOChannel *ioc; /* The I/O channel with the client */ @@ -60,8 +60,8 @@ bool vhost_user_server_start(VuServer *server, void vhost_user_server_stop(VuServer *server); -void vhost_user_server_ref(VuServer *server); -void vhost_user_server_unref(VuServer *server); +void vhost_user_server_inc_in_flight(VuServer *server); +void vhost_user_server_dec_in_flight(VuServer *server); void vhost_user_server_attach_aio_context(VuServer *server, AioContext *ctx); void vhost_user_server_detach_aio_context(VuServer *server); diff --git a/block/export/vhost-user-blk-server.c b/block/export/vhost-user-blk-server.c index e56b92f2e2..841acb36e3 100644 --- a/block/export/vhost-user-blk-server.c +++ b/block/export/vhost-user-blk-server.c @@ -50,7 +50,10 @@ static void vu_blk_req_complete(VuBlkReq *req, size_t in_len) free(req); } -/* Called with server refcount increased, must decrease before returning */ +/* + * Called with server in_flight counter increased, must decrease before + * returning. + */ static void coroutine_fn vu_blk_virtio_process_req(void *opaque) { VuBlkReq *req = opaque; @@ -68,12 +71,12 @@ static void coroutine_fn vu_blk_virtio_process_req(void *opaque) in_num, out_num); if (in_len < 0) { free(req); - vhost_user_server_unref(server); + vhost_user_server_dec_in_flight(server); return; } vu_blk_req_complete(req, in_len); - vhost_user_server_unref(server); + vhost_user_server_dec_in_flight(server); } static void vu_blk_process_vq(VuDev *vu_dev, int idx) @@ -95,7 +98,7 @@ static void vu_blk_process_vq(VuDev *vu_dev, int idx) Coroutine *co = qemu_coroutine_create(vu_blk_virtio_process_req, req); - vhost_user_server_ref(server); + vhost_user_server_inc_in_flight(server); qemu_coroutine_enter(co); } } diff --git a/util/vhost-user-server.c b/util/vhost-user-server.c index 5b6216069c..1622f8cfb3 100644 --- a/util/vhost-user-server.c +++ b/util/vhost-user-server.c @@ -75,16 +75,16 @@ static void panic_cb(VuDev *vu_dev, const char *buf) error_report("vu_panic: %s", buf); } -void vhost_user_server_ref(VuServer *server) +void vhost_user_server_inc_in_flight(VuServer *server) { assert(!server->wait_idle); - server->refcount++; + server->in_flight++; } -void vhost_user_server_unref(VuServer *server) +void vhost_user_server_dec_in_flight(VuServer *server) { - server->refcount--; - if (server->wait_idle && !server->refcount) { + server->in_flight--; + if (server->wait_idle && !server->in_flight) { aio_co_wake(server->co_trip); } } @@ -192,13 +192,13 @@ static coroutine_fn void vu_client_trip(void *opaque) /* Keep running */ } - if (server->refcount) { + if (server->in_flight) { /* Wait for requests to complete before we can unmap the memory */ server->wait_idle = true; qemu_coroutine_yield(); server->wait_idle = false; } - assert(server->refcount == 0); + assert(server->in_flight == 0); vu_deinit(vu_dev);