From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH net-next 0/3] vhost: accelerate metadata access through vmap() Date: Fri, 14 Dec 2018 10:16:08 -0500 Message-ID: <20181214101356-mutt-send-email-mst__4381.0183917687$1544800480$gmane$org@kernel.org> References: <20181213101022.12475-1-jasowang@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20181213101022.12475-1-jasowang@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Jason Wang Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org List-Id: virtualization@lists.linuxfoundation.org On Thu, Dec 13, 2018 at 06:10:19PM +0800, Jason Wang wrote: > Hi: > > This series tries to access virtqueue metadata through kernel virtual > address instead of copy_user() friends since they had too much > overheads like checks, spec barriers or even hardware feature > toggling. > > Test shows about 24% improvement on TX PPS. It should benefit other > cases as well. BTW if the issue is all the error checking, maybe we should consider using something like uaccess_catch and check in a single place. > Please review > > Jason Wang (3): > vhost: generalize adding used elem > vhost: fine grain userspace memory accessors > vhost: access vq metadata through kernel virtual address > > drivers/vhost/vhost.c | 281 ++++++++++++++++++++++++++++++++++++++---- > drivers/vhost/vhost.h | 11 ++ > 2 files changed, 266 insertions(+), 26 deletions(-) > > -- > 2.17.1