linux-kernel - Re: [PATCH RFC 7/8] mm: allow to control onlining/offlining of memory by a driver

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: <20180413155943.GY17484@dhcp22.suse.cz>
Date:   Fri, 13 Apr 2018 17:59:43 +0200
From:   Michal Hocko <mhocko@...nel.org>
To:     David Hildenbrand <david@...hat.com>
Cc:     linux-mm@...ck.org,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Boris Ostrovsky <boris.ostrovsky@...cle.com>,
        Juergen Gross <jgross@...e.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Pavel Tatashin <pasha.tatashin@...cle.com>,
        Ingo Molnar <mingo@...nel.org>,
        Vlastimil Babka <vbabka@...e.cz>,
        Dan Williams <dan.j.williams@...el.com>,
        Joonsoo Kim <iamjoonsoo.kim@....com>,
        Reza Arbab <arbab@...ux.vnet.ibm.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        open list <linux-kernel@...r.kernel.org>,
        "moderated list:XEN HYPERVISOR INTERFACE" 
        <xen-devel@...ts.xenproject.org>
Subject: Re: [PATCH RFC 7/8] mm: allow to control onlining/offlining of
 memory by a driver

On Fri 13-04-18 15:33:28, David Hildenbrand wrote:
> Some devices (esp. paravirtualized) might want to control
> - when to online/offline a memory block
> - how to online memory (MOVABLE/NORMAL)
> - in which granularity to online/offline memory
> 
> So let's add a new flag "driver_managed" and disallow to change the
> state by user space. Device onlining/offlining will still work, however
> the memory will not be actually onlined/offlined. That has to be handled
> by the device driver that owns the memory.

Is there any reason to create the memblock sysfs interface to this
memory at all? ZONE_DEVICE mem hotplug users currently do not do that
and manage the memory themselves. It seems you want to achieve the same
thing, no?
-- 
Michal Hocko
SUSE Labs