From mboxrd@z Thu Jan 1 00:00:00 1970 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=-7.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 C1D1EC10F14 for ; Tue, 23 Apr 2019 05:54:55 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 8E5FE20843 for ; Tue, 23 Apr 2019 05:54:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Xi7C00aJ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8E5FE20843 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=O+JXPFWa5HlY90NZu0IG4rEba83vk/K2lsQp7EKLPl8=; b=Xi7C00aJOQyvTsrCG+IoCpaIdV BgBLy5w8+7BKEviMbNIr3YBNv5+eIrzmXwHpd4Iv0/MTkntFU0s2+Y4WpIrE2AnXZ9hsgC1/d10o5 Q/gC3+gLGw+SX8H0lgSpdPaKdyhxXaYzRJjYZTJ9vlgLurThmEu/fx7Uwaefd6eJ4FFt6djxunF4o YN9QTGWzDzKRDNr+c33ElcB6i+zVT2HuQYeHR/WQU2/kDRdJzUE/VZdcY6PV9ziwqfG5Z2Rlsz8o6 58FVCE0KIPN5GeGt3KQABw/4ctf6hi5JiObs3LTdbL5yof/cWXog0cc38Biq/59dUyy6fdb01inys L29k84CQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hIoOG-0002Hr-30; Tue, 23 Apr 2019 05:54:48 +0000 Received: from mx1.redhat.com ([209.132.183.28]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hIoO5-00024R-OB for linux-arm-kernel@lists.infradead.org; Tue, 23 Apr 2019 05:54:39 +0000 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 62C47307D8BE; Tue, 23 Apr 2019 05:54:37 +0000 (UTC) Received: from hp-dl380pg8-01.lab.eng.pek2.redhat.com (hp-dl380pg8-01.lab.eng.pek2.redhat.com [10.73.8.10]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5F53119C7E; Tue, 23 Apr 2019 05:54:32 +0000 (UTC) From: Jason Wang To: mst@redhat.com, jasowang@redhat.com, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH V3 1/6] vhost: generalize adding used elem Date: Tue, 23 Apr 2019 01:54:15 -0400 Message-Id: <20190423055420.26408-2-jasowang@redhat.com> In-Reply-To: <20190423055420.26408-1-jasowang@redhat.com> References: <20190423055420.26408-1-jasowang@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.48]); Tue, 23 Apr 2019 05:54:37 +0000 (UTC) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190422_225437_835166_E754D916 X-CRM114-Status: GOOD ( 12.89 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: aarcange@redhat.com, hch@infradead.org, christophe.de.dinechin@gmail.com, linux-parisc@vger.kernel.org, peterx@redhat.com, James.Bottomley@hansenpartnership.com, linux-mm@kvack.org, jglisse@redhat.com, jrdr.linux@gmail.com, davem@davemloft.net, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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 351af88231ad..6df76ac8200a 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -2255,16 +2255,7 @@ 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; } -- 2.18.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel