From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Subject: [RFC PATCH V2 0/3] vhost: accelerate metadata access through vmap() Date: Fri, 28 Dec 2018 15:55:34 +0800 Message-ID: <20181228075537.21402-1-jasowang@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: 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: mst@redhat.com, jasowang@redhat.com, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: virtualization@lists.linuxfoundation.org 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. Changes from V1: - instead of pinning pages, use MMU notifier to invalidate vmaps and remap duing metadata prefetch - fix build warning on MIPS 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/net.c | 4 +- drivers/vhost/vhost.c | 362 ++++++++++++++++++++++++++++++++++++++---- drivers/vhost/vhost.h | 15 +- 3 files changed, 348 insertions(+), 33 deletions(-) -- 2.17.1