From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH V5 0/9] Fixes for vhost metadata acceleration Date: Sun, 1 Sep 2019 14:02:44 -0400 Message-ID: <20190901140220-mutt-send-email-mst@kernel.org> References: <20190809054851.20118-1-jasowang@redhat.com> <20190810134948-mutt-send-email-mst@kernel.org> <360a3b91-1ac5-84c0-d34b-a4243fa748c4@redhat.com> <20190812054429-mutt-send-email-mst@kernel.org> <663be71f-f96d-cfbc-95a0-da0ac6b82d9f@redhat.com> <20190819162733-mutt-send-email-mst@kernel.org> <9325de4b-1d79-eb19-306e-e7a8fa8cc1a5@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Content-Disposition: inline In-Reply-To: <9325de4b-1d79-eb19-306e-e7a8fa8cc1a5@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: kvm@vger.kernel.org, jgg@ziepe.ca, netdev@vger.kernel.org, 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[79.180.62.110]) by smtp.gmail.com with ESMTPSA id i20sm5379783qkk.67.2019.09.01.11.02.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 01 Sep 2019 11:02:49 -0700 (PDT) Date: Sun, 1 Sep 2019 14:02:44 -0400 From: "Michael S. Tsirkin" To: Jason Wang Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, jgg@ziepe.ca Subject: Re: [PATCH V5 0/9] Fixes for vhost metadata acceleration Message-ID: <20190901140220-mutt-send-email-mst@kernel.org> References: <20190809054851.20118-1-jasowang@redhat.com> <20190810134948-mutt-send-email-mst@kernel.org> <360a3b91-1ac5-84c0-d34b-a4243fa748c4@redhat.com> <20190812054429-mutt-send-email-mst@kernel.org> <663be71f-f96d-cfbc-95a0-da0ac6b82d9f@redhat.com> <20190819162733-mutt-send-email-mst@kernel.org> <9325de4b-1d79-eb19-306e-e7a8fa8cc1a5@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <9325de4b-1d79-eb19-306e-e7a8fa8cc1a5@redhat.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, Aug 20, 2019 at 10:29:32AM +0800, Jason Wang wrote: > > On 2019/8/20 上午5:08, Michael S. Tsirkin wrote: > > On Tue, Aug 13, 2019 at 04:12:49PM +0800, Jason Wang wrote: > > > On 2019/8/12 下午5:49, Michael S. Tsirkin wrote: > > > > On Mon, Aug 12, 2019 at 10:44:51AM +0800, Jason Wang wrote: > > > > > On 2019/8/11 上午1:52, Michael S. Tsirkin wrote: > > > > > > On Fri, Aug 09, 2019 at 01:48:42AM -0400, Jason Wang wrote: > > > > > > > Hi all: > > > > > > > > > > > > > > This series try to fix several issues introduced by meta data > > > > > > > accelreation series. Please review. > > > > > > > > > > > > > > Changes from V4: > > > > > > > - switch to use spinlock synchronize MMU notifier with accessors > > > > > > > > > > > > > > Changes from V3: > > > > > > > - remove the unnecessary patch > > > > > > > > > > > > > > Changes from V2: > > > > > > > - use seqlck helper to synchronize MMU notifier with vhost worker > > > > > > > > > > > > > > Changes from V1: > > > > > > > - try not use RCU to syncrhonize MMU notifier with vhost worker > > > > > > > - set dirty pages after no readers > > > > > > > - return -EAGAIN only when we find the range is overlapped with > > > > > > > metadata > > > > > > > > > > > > > > Jason Wang (9): > > > > > > > vhost: don't set uaddr for invalid address > > > > > > > vhost: validate MMU notifier registration > > > > > > > vhost: fix vhost map leak > > > > > > > vhost: reset invalidate_count in vhost_set_vring_num_addr() > > > > > > > vhost: mark dirty pages during map uninit > > > > > > > vhost: don't do synchronize_rcu() in vhost_uninit_vq_maps() > > > > > > > vhost: do not use RCU to synchronize MMU notifier with worker > > > > > > > vhost: correctly set dirty pages in MMU notifiers callback > > > > > > > vhost: do not return -EAGAIN for non blocking invalidation too early > > > > > > > > > > > > > > drivers/vhost/vhost.c | 202 +++++++++++++++++++++++++----------------- > > > > > > > drivers/vhost/vhost.h | 6 +- > > > > > > > 2 files changed, 122 insertions(+), 86 deletions(-) > > > > > > This generally looks more solid. > > > > > > > > > > > > But this amounts to a significant overhaul of the code. > > > > > > > > > > > > At this point how about we revert 7f466032dc9e5a61217f22ea34b2df932786bbfc > > > > > > for this release, and then re-apply a corrected version > > > > > > for the next one? > > > > > If possible, consider we've actually disabled the feature. How about just > > > > > queued those patches for next release? > > > > > > > > > > Thanks > > > > Sorry if I was unclear. My idea is that > > > > 1. I revert the disabled code > > > > 2. You send a patch readding it with all the fixes squashed > > > > 3. Maybe optimizations on top right away? > > > > 4. We queue *that* for next and see what happens. > > > > > > > > And the advantage over the patchy approach is that the current patches > > > > are hard to review. E.g. it's not reasonable to ask RCU guys to review > > > > the whole of vhost for RCU usage but it's much more reasonable to ask > > > > about a specific patch. > > > > > > Ok. Then I agree to revert. > > > > > > Thanks > > Great, so please send the following: > > - revert > > - squashed and fixed patch > > > Just to confirm, do you want me to send a single series or two? > > Thanks > One is fine. -- MST