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Date:   Tue, 30 Oct 2018 09:17:57 +0100
From:   Michal Hocko <mhocko@kernel.org>
To:     Dan Williams <dan.j.williams@intel.com>
Cc:     alexander.h.duyck@linux.intel.com, Linux MM <linux-mm@kvack.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-nvdimm <linux-nvdimm@lists.01.org>,
        Pasha Tatashin <pavel.tatashin@microsoft.com>,
        Dave Hansen <dave.hansen@intel.com>,
        =?iso-8859-1?B?Suly9G1l?= Glisse <jglisse@redhat.com>,
        rppt@linux.vnet.ibm.com, Ingo Molnar <mingo@kernel.org>,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Zhang Yi <yi.z.zhang@linux.intel.com>,
        osalvador@techadventures.net
Subject: Re: [PATCH v5 4/4] mm: Defer ZONE_DEVICE page initialization to the
 point where we init pgmap
Message-ID: <20181030081757.GX32673@dhcp22.suse.cz>
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On Mon 29-10-18 23:55:12, Dan Williams wrote:
> On Mon, Oct 29, 2018 at 11:29 PM Michal Hocko <mhocko@kernel.org> wrote:
> >
> > On Mon 29-10-18 12:59:11, Alexander Duyck wrote:
> > > On Mon, 2018-10-29 at 19:18 +0100, Michal Hocko wrote:
> [..]
> > > The patches Andrew pushed addressed the immediate issue so that now
> > > systems with nvdimm/DAX memory can at least initialize quick enough
> > > that systemd doesn't refuse to mount the root file system due to a
> > > timeout.
> >
> > This is about the first time you actually mention that. I have re-read
> > the cover letter and all changelogs of patches in this serious. Unless I
> > have missed something there is nothing about real users hitting issues
> > out there. nvdimm is still considered a toy because there is no real HW
> > users can play with.
> 
> Yes, you have missed something, because that's incorrect. There's been
> public articles about these parts sampling since May.
> 
>     https://www.anandtech.com/show/12828/intel-launches-optane-dimms-up-to-512gb-apache-pass-is-here

indeed!

> That testing identified this initialization performance problem and
> thankfully got it addressed in time for the current merge window.

And I still cannot see a word about that in changelogs.

-- 
Michal Hocko
SUSE Labs