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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,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 E37D9C282C3 for ; Fri, 25 Jan 2019 03:00:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BEF11217D7 for ; Fri, 25 Jan 2019 03:00:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728737AbfAYDAb (ORCPT ); Thu, 24 Jan 2019 22:00:31 -0500 Received: from mx1.redhat.com ([209.132.183.28]:36366 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725991AbfAYDAa (ORCPT ); Thu, 24 Jan 2019 22:00:30 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 3E7002CD7EC; Fri, 25 Jan 2019 03:00:30 +0000 (UTC) Received: from redhat.com (ovpn-120-141.rdu2.redhat.com [10.10.120.141]) by smtp.corp.redhat.com (Postfix) with SMTP id 6B78917117; Fri, 25 Jan 2019 03:00:27 +0000 (UTC) Date: Thu, 24 Jan 2019 22:00:27 -0500 From: "Michael S. Tsirkin" To: Jason Wang Cc: virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Subject: Re: [PATCH net-next V4 5/5] vhost: access vq metadata through kernel virtual address Message-ID: <20190124215912-mutt-send-email-mst@kernel.org> References: <20190123095557.30168-1-jasowang@redhat.com> <20190123095557.30168-6-jasowang@redhat.com> <20190123085821-mutt-send-email-mst@kernel.org> <335ba55b-087f-4b35-6311-540070b9647f@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <335ba55b-087f-4b35-6311-540070b9647f@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Fri, 25 Jan 2019 03:00:30 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 24, 2019 at 12:07:54PM +0800, Jason Wang wrote: > > Meanwhile, could you pls post data comparing this last patch with the > > below? This removes the speculation barrier replacing it with a > > (useless but at least more lightweight) data dependency. > > > SMAP off > > Your patch: 7.2MPPs > > vmap: 7.4Mpps OK so while we keep looking into vmap, why don't we merge something like the below? Seems quite straight forward ... > I don't test SMAP on, since it will be much slow for sure. > > Thanks > > > > > > Thanks! > > > > > > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > > index bac939af8dbb..352ee7e14476 100644 > > --- a/drivers/vhost/vhost.c > > +++ b/drivers/vhost/vhost.c > > @@ -739,7 +739,7 @@ static int vhost_copy_to_user(struct vhost_virtqueue *vq, void __user *to, > > int ret; > > if (!vq->iotlb) > > - return __copy_to_user(to, from, size); > > + return copy_to_user(to, from, size); > > else { > > /* This function should be called after iotlb > > * prefetch, which means we're sure that all vq > > @@ -752,7 +752,7 @@ static int vhost_copy_to_user(struct vhost_virtqueue *vq, void __user *to, > > VHOST_ADDR_USED); > > if (uaddr) > > - return __copy_to_user(uaddr, from, size); > > + return copy_to_user(uaddr, from, size); > > ret = translate_desc(vq, (u64)(uintptr_t)to, size, vq->iotlb_iov, > > ARRAY_SIZE(vq->iotlb_iov), > > @@ -774,7 +774,7 @@ static int vhost_copy_from_user(struct vhost_virtqueue *vq, void *to, > > int ret; > > if (!vq->iotlb) > > - return __copy_from_user(to, from, size); > > + return copy_from_user(to, from, size); > > else { > > /* This function should be called after iotlb > > * prefetch, which means we're sure that vq > > @@ -787,7 +787,7 @@ static int vhost_copy_from_user(struct vhost_virtqueue *vq, void *to, > > struct iov_iter f; > > if (uaddr) > > - return __copy_from_user(to, uaddr, size); > > + return copy_from_user(to, uaddr, size); > > ret = translate_desc(vq, (u64)(uintptr_t)from, size, vq->iotlb_iov, > > ARRAY_SIZE(vq->iotlb_iov), > > @@ -855,13 +855,13 @@ static inline void __user *__vhost_get_user(struct vhost_virtqueue *vq, > > ({ \ > > int ret = -EFAULT; \ > > if (!vq->iotlb) { \ > > - ret = __put_user(x, ptr); \ > > + ret = put_user(x, ptr); \ > > } else { \ > > __typeof__(ptr) to = \ > > (__typeof__(ptr)) __vhost_get_user(vq, ptr, \ > > sizeof(*ptr), VHOST_ADDR_USED); \ > > if (to != NULL) \ > > - ret = __put_user(x, to); \ > > + ret = put_user(x, to); \ > > else \ > > ret = -EFAULT; \ > > } \ > > @@ -872,14 +872,14 @@ static inline void __user *__vhost_get_user(struct vhost_virtqueue *vq, > > ({ \ > > int ret; \ > > if (!vq->iotlb) { \ > > - ret = __get_user(x, ptr); \ > > + ret = get_user(x, ptr); \ > > } else { \ > > __typeof__(ptr) from = \ > > (__typeof__(ptr)) __vhost_get_user(vq, ptr, \ > > sizeof(*ptr), \ > > type); \ > > if (from != NULL) \ > > - ret = __get_user(x, from); \ > > + ret = get_user(x, from); \ > > else \ > > ret = -EFAULT; \ > > } \