From patchwork Wed Jan 23 09:55:53 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Wang X-Patchwork-Id: 10776901 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5CDF914E5 for ; Wed, 23 Jan 2019 09:56:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4C7952AC14 for ; Wed, 23 Jan 2019 09:56:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4046F2B4F7; Wed, 23 Jan 2019 09:56:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E31F22AC14 for ; Wed, 23 Jan 2019 09:56:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727323AbfAWJ4K (ORCPT ); Wed, 23 Jan 2019 04:56:10 -0500 Received: from mx1.redhat.com ([209.132.183.28]:48750 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727098AbfAWJ4J (ORCPT ); Wed, 23 Jan 2019 04:56:09 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E13A63695F; Wed, 23 Jan 2019 09:56:08 +0000 (UTC) Received: from jason-ThinkPad-T450s.redhat.com (ovpn-12-89.pek2.redhat.com [10.72.12.89]) by smtp.corp.redhat.com (Postfix) with ESMTP id 63E8260168; Wed, 23 Jan 2019 09:56:06 +0000 (UTC) From: Jason Wang To: virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, jasowang@redhat.com Cc: mst@redhat.com, kvm@vger.kernel.org Subject: [PATCH net-next V4 1/5] vhost: generalize adding used elem Date: Wed, 23 Jan 2019 17:55:53 +0800 Message-Id: <20190123095557.30168-2-jasowang@redhat.com> In-Reply-To: <20190123095557.30168-1-jasowang@redhat.com> References: <20190123095557.30168-1-jasowang@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Wed, 23 Jan 2019 09:56:09 +0000 (UTC) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Use one generic vhost_copy_to_user() instead of two dedicated accessor. This will simplify the conversion to fine grain accessors. About 2% improvement of PPS were seen during vitio-user txonly test. Signed-off-by: Jason Wang --- drivers/vhost/vhost.c | 11 +---------- 1 file changed, 1 insertion(+), 10 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 15a216cdd507..14fad2577df3 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -2250,16 +2250,7 @@ static int __vhost_add_used_n(struct vhost_virtqueue *vq, start = vq->last_used_idx & (vq->num - 1); used = vq->used->ring + start; - if (count == 1) { - if (vhost_put_user(vq, heads[0].id, &used->id)) { - vq_err(vq, "Failed to write used id"); - return -EFAULT; - } - if (vhost_put_user(vq, heads[0].len, &used->len)) { - vq_err(vq, "Failed to write used len"); - return -EFAULT; - } - } else if (vhost_copy_to_user(vq, used, heads, count * sizeof *used)) { + if (vhost_copy_to_user(vq, used, heads, count * sizeof *used)) { vq_err(vq, "Failed to write used"); return -EFAULT; }