linux-kernel - Re: [PATCH 2/2] mm, slab: support NUMA policy for large kmalloc

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 for Android: free password hash cracker in your pocket

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

Message-ID: <b8a5dc9d-3697-47b3-bf66-f9bd726389fb@suse.cz>
Date: Thu, 29 May 2025 17:59:43 +0200
From: Vlastimil Babka <vbabka@...e.cz>
To: "Christoph Lameter (Ampere)" <cl@...two.org>
Cc: David Rientjes <rientjes@...gle.com>,
 Andrew Morton <akpm@...ux-foundation.org>,
 Roman Gushchin <roman.gushchin@...ux.dev>, Harry Yoo <harry.yoo@...cle.com>,
 Matthew Wilcox <willy@...radead.org>, linux-mm@...ck.org,
 linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/2] mm, slab: support NUMA policy for large kmalloc

On 5/29/25 16:57, Christoph Lameter (Ampere) wrote:
> On Thu, 29 May 2025, Vlastimil Babka wrote:
> 
>> The slab allocator observes the task's numa policy in various places
>> such as allocating slab pages. Large kmalloc allocations currently do
>> not, which seems to be an unintended omission. It is simple to correct
>> that, so make ___kmalloc_large_node() behave the same way as
>> alloc_slab_page().
> 
> Large kmalloc allocation lead to the use of the page allocator which
> implements the NUMA policies for the allocations.
>
> This patch is not necessary.

I'm confused, as that's only true depending on which page allocator entry
point you use. AFAICS before this series, it's using
alloc_pages_node_noprof() which only does


        if (nid == NUMA_NO_NODE)
                nid = numa_mem_id();

and no mempolicies.

I see this patch as analogical to your commit 1941b31482a6 ("Reenable NUMA
policy support in the slab allocator")

Am I missing something?