linux-kernel - Re: [RFC PATCH] mm, memory_hotplug: support movable

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20170601155204.GB8088@dhcp22.suse.cz>
Date:   Thu, 1 Jun 2017 17:52:31 +0200
From:   Michal Hocko <mhocko@...nel.org>
To:     Reza Arbab <arbab@...ux.vnet.ibm.com>
Cc:     Vlastimil Babka <vbabka@...e.cz>, linux-mm@...ck.org,
        Andrew Morton <akpm@...ux-foundation.org>,
        Mel Gorman <mgorman@...e.de>,
        Andrea Arcangeli <aarcange@...hat.com>,
        Jerome Glisse <jglisse@...hat.com>,
        Yasuaki Ishimatsu <yasu.isimatu@...il.com>,
        qiuxishi@...wei.com, Kani Toshimitsu <toshi.kani@....com>,
        slaoub@...il.com, Joonsoo Kim <js1304@...il.com>,
        Andi Kleen <ak@...ux.intel.com>,
        David Rientjes <rientjes@...gle.com>,
        Daniel Kiper <daniel.kiper@...cle.com>,
        Igor Mammedov <imammedo@...hat.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        LKML <linux-kernel@...r.kernel.org>
Subject: Re: [RFC PATCH] mm, memory_hotplug: support movable_node for
 hotplugable nodes

On Thu 01-06-17 10:47:46, Reza Arbab wrote:
> On Thu, Jun 01, 2017 at 05:38:38PM +0200, Michal Hocko wrote:
> >On Thu 01-06-17 10:19:36, Reza Arbab wrote:
> >>The x86 SRAT (or the dt, on other platforms) can describe memory as
> >>hotpluggable. See memblock_mark_hotplug(). That's only for memory present at
> >>boot, though.
> >
> >Yes but lose that information after the memblock is gone and numa fully
> >initialized. Or can we reconstruct that somehow?
> 
> I'm not sure you'd have to. At boot time, those markings are used to
> determine the initial boundaries of ZONE_MOVABLE. So if you removed these
> memblocks, then readded them, they would still be in ZONE_MOVABLE.

Yes but that already works like that. I am nore interested in the case
when the node goes away and it is added again. echo online > ... would
result in a non-movable memory and that is the inconsistency I tried to
call out in the changelog

-- 
Michal Hocko
SUSE Labs