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  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]
Date:   Mon, 15 Jul 2019 12:51:27 +0200
From:   David Hildenbrand <david@...hat.com>
To:     Michal Hocko <mhocko@...nel.org>
Cc:     linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        linux-ia64@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
        linux-s390@...r.kernel.org, linux-sh@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, akpm@...ux-foundation.org,
        Dan Williams <dan.j.williams@...el.com>,
        Wei Yang <richard.weiyang@...il.com>,
        Igor Mammedov <imammedo@...hat.com>,
        Martin Schwidefsky <schwidefsky@...ibm.com>,
        Heiko Carstens <heiko.carstens@...ibm.com>,
        Mike Rapoport <rppt@...ux.vnet.ibm.com>,
        Vasily Gorbik <gor@...ux.ibm.com>,
        Oscar Salvador <osalvador@...e.com>
Subject: Re: [PATCH v3 02/11] s390x/mm: Fail when an altmap is used for
 arch_add_memory()

On 01.07.19 14:46, Michal Hocko wrote:
> On Mon 01-07-19 09:43:06, Michal Hocko wrote:
>> On Mon 27-05-19 13:11:43, David Hildenbrand wrote:
>>> ZONE_DEVICE is not yet supported, fail if an altmap is passed, so we
>>> don't forget arch_add_memory()/arch_remove_memory() when unlocking
>>> support.
>>
>> Why do we need this? Sure ZONE_DEVICE is not supported for s390 and so
>> might be the case for other arches which support hotplug. I do not see
>> much point in adding warning to each of them.
> 
> I would drop this one. If there is a strong reason to have something
> like that it should come with a better explanation and it can be done on
> top.
> 

This was requested by Dan and I agree it is the right thing to do. In
the context of paravirtualized devices (e.g., virtio-pmem), it makes
sense to block functionality an arch does not support.

I'll leave the decision to Andrew.

-- 

Thanks,

David / dhildenb

Powered by blists - more mailing lists