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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 37828C31E40 for ; Mon, 12 Aug 2019 09:49:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1183C20842 for ; Mon, 12 Aug 2019 09:49:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727602AbfHLJtR (ORCPT ); Mon, 12 Aug 2019 05:49:17 -0400 Received: from mail-qk1-f194.google.com ([209.85.222.194]:35857 "EHLO mail-qk1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727425AbfHLJtP (ORCPT ); Mon, 12 Aug 2019 05:49:15 -0400 Received: by mail-qk1-f194.google.com with SMTP id d23so1650983qko.3 for ; Mon, 12 Aug 2019 02:49:14 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=TeG3wutKuFLwVY8GXTa6M+xMk4IsoY0IuBgfuWlKI8w=; b=LVPv9z9Q2ZpjlDK8fPKYwW5SDrlBje/i2RQeJFhad8GW/uZ+Yh2LLyk+w1pEhzlKri jzx6cS8ykAeZyd2sw+1qmJVd31THImM8y7c3iSDEV/klVB6kjNwKg2lo202Nj2ZZ1Ytb ed1MVgCLA//a9mcGuyJVpMagTgK5AIboZxxa0j+oqav+xwB5rlDYp9POk44BD0vOXGFw Gq2bhBNzSMgqx/+S2WolOZFt2rhjOlwAugbfmOie++hAjNQFxifj+ETlz0oI4DuMYwt2 Ke9DLUsTfDv+LIVAH2yUwSkD53jF9Av0oaUIoAwPKiNCslLZYBCmweRz1YvBbU2bRumr Cuiw== X-Gm-Message-State: APjAAAUjyda1tGzfyMMsM+4oEWQzs5yJQXZ8QgnX8xShDl1Xzx3lgySA dpnT1lsYGmUW40UftD/aXkNXjDv8+6ri7wxw X-Google-Smtp-Source: APXvYqxP0GkCXonLtypbly8kLbgJ4TN28n5gWEUnHayGxRExqWLocZL6kaOvmE9QUvNpukx30J3PxA== X-Received: by 2002:a37:79c7:: with SMTP id u190mr3917170qkc.26.1565603354162; Mon, 12 Aug 2019 02:49:14 -0700 (PDT) Received: from redhat.com ([147.234.38.29]) by smtp.gmail.com with ESMTPSA id m27sm52517604qtu.31.2019.08.12.02.49.10 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Mon, 12 Aug 2019 02:49:13 -0700 (PDT) Date: Mon, 12 Aug 2019 05:49:08 -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: <20190812054429-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> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <360a3b91-1ac5-84c0-d34b-a4243fa748c4@redhat.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. -- MST