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 EB30FC32756 for ; Sat, 10 Aug 2019 19:12:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C6936208C3 for ; Sat, 10 Aug 2019 19:12:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726084AbfHJTMT (ORCPT ); Sat, 10 Aug 2019 15:12:19 -0400 Received: from mail-qk1-f195.google.com ([209.85.222.195]:45536 "EHLO mail-qk1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725884AbfHJTMT (ORCPT ); Sat, 10 Aug 2019 15:12:19 -0400 Received: by mail-qk1-f195.google.com with SMTP id m2so401606qki.12 for ; Sat, 10 Aug 2019 12:12:18 -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=tOm/MfXC722ZZDGZkYyy/bxra5b24Gt/HS1+G7EfviI=; b=aVlvcv1S46sB5tN21dd0pSvJ3ajY/oaG1IEMAN7xxScqsfdxguoyQntKN7UmyBQUFa VmRRnxYoffIIkMajJOYMqxUTu/2I6KB6FpgaFgfRGiDi2y2hIcmzf/maFEvTA0NEubk6 FUxF3/fh0aH91rauBe0l1xAWx9RPDYxoYLWe0g89R05Ew6ZikkUlFNdVAWQRqaB5R7ed w9bSBkiTkr0VEwayaugAVe/2S0jqyQUYkL/EHCiJXKFY3p8WYE0xiPlEBe0uYKGlJvb+ HYVRMmKAcqjukPypQTvsWAq/mSoDa9wDhVGkWjHbMD+s7xA6g/3RE/7ZlE2MTkV8HzMK pfEg== X-Gm-Message-State: APjAAAUYpyf/WtHfRtp/XuVN6Mg77ed0vavmvZbsqriJObx4yF/htNoL NMxXVBCRx/oWwSrJ2piXcIosBg== X-Google-Smtp-Source: APXvYqy9zmxhh9QafC0RnwL+m0pBIJpGi6lXzl9adS3Ij5sGenWXNRYs/XzZWBUSfehxs1JFSId7lA== X-Received: by 2002:a37:516:: with SMTP id 22mr23794866qkf.308.1565464338086; Sat, 10 Aug 2019 12:12:18 -0700 (PDT) Received: from redhat.com (bzq-79-181-91-42.red.bezeqint.net. [79.181.91.42]) by smtp.gmail.com with ESMTPSA id q17sm40074395qtl.13.2019.08.10.12.12.14 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Sat, 10 Aug 2019 12:12:16 -0700 (PDT) Date: Sat, 10 Aug 2019 15:12:11 -0400 From: "Michael S. Tsirkin" To: Jason Wang Cc: Jason Gunthorpe , kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH V5 0/9] Fixes for vhost metadata acceleration Message-ID: <20190810150611-mutt-send-email-mst@kernel.org> References: <20190807070617.23716-1-jasowang@redhat.com> <20190807070617.23716-8-jasowang@redhat.com> <20190807120738.GB1557@ziepe.ca> <1000f8a3-19a9-0383-61e5-ba08ddc9fcba@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1000f8a3-19a9-0383-61e5-ba08ddc9fcba@redhat.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Thu, Aug 08, 2019 at 08:54:54PM +0800, Jason Wang wrote: > I don't have any objection to convert  to spinlock() but just want to > know if any case that the above smp_mb() + counter looks good to you? So how about we try this: - revert the original patch for this release - new safe patch with a spinlock for the next release - whatever improvements we can come up with on top Thoughts? Because I think this needs much more scrutiny than we can give an incremental patch. -- MST