linux-kernel - Re: [PATCH v1] drivers/base/node.c: Simplify unregister_memory_block_under

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]

Date:   Fri, 19 Jul 2019 11:05:51 +0200
From:   David Hildenbrand <david@...hat.com>
To:     Michal Hocko <mhocko@...nel.org>
Cc:     linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Stephen Rothwell <sfr@...b.auug.org.au>,
        Pavel Tatashin <pasha.tatashin@...een.com>,
        Oscar Salvador <osalvador@...e.de>
Subject: Re: [PATCH v1] drivers/base/node.c: Simplify
 unregister_memory_block_under_nodes()

On 19.07.19 10:42, Michal Hocko wrote:
> On Thu 18-07-19 16:22:39, David Hildenbrand wrote:
>> We don't allow to offline memory block devices that belong to multiple
>> numa nodes. Therefore, such devices can never get removed. It is
>> sufficient to process a single node when removing the memory block.
>>
>> Remember for each memory block if it belongs to no, a single, or mixed
>> nodes, so we can use that information to skip unregistering or print a
>> warning (essentially a safety net to catch BUGs).
> 
> I do not really like NUMA_NO_NODE - 1 thing. This is yet another invalid
> node that is magic. Why should we even care? In other words why is this
> patch an improvement?

Oh, and to answer that part of the question:

We no longer have to iterate over each pfn of a memory block to be removed.

-- 

Thanks,

David / dhildenb