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=-8.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 65CDEC4338F for ; Tue, 17 Aug 2021 09:32:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4C4AE60184 for ; Tue, 17 Aug 2021 09:32:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235401AbhHQJdA (ORCPT ); Tue, 17 Aug 2021 05:33:00 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:20107 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235402AbhHQJc7 (ORCPT ); Tue, 17 Aug 2021 05:32:59 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1629192739; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=tXO0rYgdhyeDYBKbOyKfCbfOOPtHG4G1MWXLBg7l68E=; b=PzlrqY4BzM/4Y0tHhazPr+/iXxOpEJQo9VUvoxJerkMnUZ6le8fCfz7CE1IZdCNmIcadl2 P/V/+hGYh+hWxv2sPI9J7+Zo85xyEcZV65qfvVwaXh6woHL+rINVlRWkz87cP5v6Q+BXu2 5N+eYNZGDyTMWqyKGPFl6Zlo8oCmjAY= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-577-_rVxnm4uM3qkTt60KOw0OA-1; Tue, 17 Aug 2021 05:32:18 -0400 X-MC-Unique: _rVxnm4uM3qkTt60KOw0OA-1 Received: by mail-wm1-f71.google.com with SMTP id o3-20020a05600c510300b002e6dd64e896so699491wms.1 for ; Tue, 17 Aug 2021 02:32:18 -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:in-reply-to:user-agent; bh=tXO0rYgdhyeDYBKbOyKfCbfOOPtHG4G1MWXLBg7l68E=; b=bYAcezjAz1kMPjaaCV2upTTC8mWvwLBO03kZLy/AiUzce3Mv0+tOxYjjtQVOpUEckR bpU0tbirXc4ysP0MjY+KkpT3W80h7XsVZeGkUtoq8E9Zt6BAdIAQL1JZ/5Mvk5UDbBC3 NWq4v5o4iNw8DbZUR051EYqmKnnfDqu8Mk5cOQc9pgjcMNn1YXguEtS4DiXzWKRawziR KwQ6HNQiOD079Pv0/GOCQSr8AnsvjXiyvfDpomEgUKuWktPNXk8zhriZ8cLxAik43YhV 598Yir/5QzW21gxyJ7ojNaU+JmVmg+nwzS2mIhVM5RRUpxPVrVo6tg/oO7XZW+r65MlD RenQ== X-Gm-Message-State: AOAM530887krbnMYOnB3c5f/pXHrFsQwXtYSzDrtS47osCz7Utd5c/Rj gS2uxmdvFf6TIiA2vBqE43C2sO04RBDWfbRTlV/iCKL7GGuEkmTWZPCyZgcq0sRt0C1ESU/ztJI UtjscnDqTxBfSh7zHsrv1soQanw== X-Received: by 2002:a1c:1f17:: with SMTP id f23mr2445349wmf.136.1629192737020; Tue, 17 Aug 2021 02:32:17 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzZebtc9nXfqDyMD/ZWMOGBaaLkmeU7uLr7GiJexUrvciVWIfZqrerPJXKpkvUSOmHuGSxz7w== X-Received: by 2002:a1c:1f17:: with SMTP id f23mr2445334wmf.136.1629192736834; Tue, 17 Aug 2021 02:32:16 -0700 (PDT) Received: from work-vm (cpc109021-salf6-2-0-cust453.10-2.cable.virginm.net. [82.29.237.198]) by smtp.gmail.com with ESMTPSA id e25sm2097816wra.90.2021.08.17.02.32.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 17 Aug 2021 02:32:16 -0700 (PDT) Date: Tue, 17 Aug 2021 10:32:14 +0100 From: "Dr. David Alan Gilbert" To: Miklos Szeredi Cc: Jeffle Xu , virtualization@lists.linux-foundation.org, virtio-fs-list , Joseph Qi , linux-fsdevel@vger.kernel.org, Vivek Goyal Subject: Re: [Virtio-fs] [PATCH v4 0/8] fuse,virtiofs: support per-file DAX Message-ID: References: <20210817022220.17574-1-jefflexu@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/2.0.7 (2021-05-04) Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org * Miklos Szeredi (miklos@szeredi.hu) wrote: > On Tue, 17 Aug 2021 at 04:22, Jeffle Xu wrote: > > > > This patchset adds support of per-file DAX for virtiofs, which is > > inspired by Ira Weiny's work on ext4[1] and xfs[2]. > > Can you please explain the background of this change in detail? > > Why would an admin want to enable DAX for a particular virtiofs file > and not for others? Where we're contending on virtiofs dax cache size it makes a lot of sense; it's quite expensive for us to map something into the cache (especially if we push something else out), so selectively DAXing files that are expected to be hot could help reduce cache churn. Dave > Thanks, > Miklos > > _______________________________________________ > Virtio-fs mailing list > Virtio-fs@redhat.com > https://listman.redhat.com/mailman/listinfo/virtio-fs > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK