From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id DC11F41DB5; Thu, 2 Mar 2023 17:19:51 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id F16A542D47; Thu, 2 Mar 2023 17:18:43 +0100 (CET) Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by mails.dpdk.org (Postfix) with ESMTP id C5C1D4161A for ; Thu, 2 Mar 2023 17:18:31 +0100 (CET) Received: by linux.microsoft.com (Postfix, from userid 1086) id 5953220BC5E8; Thu, 2 Mar 2023 08:18:30 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 5953220BC5E8 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1677773910; bh=EjT2YfPqjhabdlEzSFVKsCJHc1NqDxu/IrEC1n0sd5U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ghR/bvodS4I6h2yrdqlSbO8vPYH0RXflnBqzSfA+xQmM7eE+UATlJ7YNKe3G9q/KY 6SjboWyJY+5erSd4TYkR78sqn6o4JuIXHasaDymkwAKAQKNa3rj9h4mz/iGJOAo1xL XA6x9yKq6JO+EI0zaz1swE3lcNFjJ4vNrRPAvhVU= From: Tyler Retzlaff To: dev@dpdk.org Cc: Honnappa.Nagarahalli@arm.com, thomas@monjalon.net, bruce.richardson@intel.com, mb@smartsharesystems.com, Ruifeng.Wang@arm.com, maxime.coquelin@redhat.com, Tyler Retzlaff Subject: [PATCH v2 08/17] net/virtio: use previous value atomic fetch operations Date: Thu, 2 Mar 2023 08:18:13 -0800 Message-Id: <1677773902-5167-9-git-send-email-roretzla@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1677773902-5167-1-git-send-email-roretzla@linux.microsoft.com> References: <1677718068-2412-1-git-send-email-roretzla@linux.microsoft.com> <1677773902-5167-1-git-send-email-roretzla@linux.microsoft.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Use __atomic_fetch_{add,and,or,sub,xor} instead of __atomic_{add,and,or,sub,xor}_fetch when we have no interest in the result of the operation. Reduces unnecessary codegen that provided the result of the atomic operation that was not used. Change brings closer alignment with atomics available in C11 standard and will reduce review effort when they are integrated. Signed-off-by: Tyler Retzlaff Acked-by: Morten Brørup Reviewed-by: Maxime Coquelin --- drivers/net/virtio/virtio_user/virtio_user_dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c b/drivers/net/virtio/virtio_user/virtio_user_dev.c index f46a131..2b4607a 100644 --- a/drivers/net/virtio/virtio_user/virtio_user_dev.c +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c @@ -1025,7 +1025,7 @@ int virtio_user_stop_device(struct virtio_user_dev *dev) uep->id = desc_idx; uep->len = n_descs; - __atomic_add_fetch(&vring->used->idx, 1, __ATOMIC_RELAXED); + __atomic_fetch_add(&vring->used->idx, 1, __ATOMIC_RELAXED); } } -- 1.8.3.1