linux-kernel - Re: [PATCH v3 18/21] slab: update overview comments

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: <1e3092b1-23df-441d-8849-84aa0632ee88@suse.cz>
Date: Thu, 22 Jan 2026 09:49:14 +0100
From: Vlastimil Babka <vbabka@...e.cz>
To: Harry Yoo <harry.yoo@...cle.com>
Cc: Petr Tesarik <ptesarik@...e.com>, Christoph Lameter <cl@...two.org>,
 David Rientjes <rientjes@...gle.com>,
 Roman Gushchin <roman.gushchin@...ux.dev>, Hao Li <hao.li@...ux.dev>,
 Andrew Morton <akpm@...ux-foundation.org>,
 Uladzislau Rezki <urezki@...il.com>,
 "Liam R. Howlett" <Liam.Howlett@...cle.com>,
 Suren Baghdasaryan <surenb@...gle.com>,
 Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
 Alexei Starovoitov <ast@...nel.org>, linux-mm@...ck.org,
 linux-kernel@...r.kernel.org, linux-rt-devel@...ts.linux.dev,
 bpf@...r.kernel.org, kasan-dev@...glegroups.com
Subject: Re: [PATCH v3 18/21] slab: update overview comments

On 1/22/26 07:41, Harry Yoo wrote:
> On Fri, Jan 16, 2026 at 03:40:38PM +0100, Vlastimil Babka wrote:
>> The changes related to sheaves made the description of locking and other
>> details outdated. Update it to reflect current state.
>> 
>> Also add a new copyright line due to major changes.
>> 
>> Reviewed-by: Suren Baghdasaryan <surenb@...gle.com>
>> Signed-off-by: Vlastimil Babka <vbabka@...e.cz>
>> ---
>> @@ -112,47 +123,46 @@
>> + *   node->barn->lock (spinlock)
>>   *
>> - *   lockless fastpaths
>> + *   Lockless freeing
>> + *
>> + *   Objects may have to be freed to their slabs when they are from a remote
>> + *   node (where we want to avoid filling local sheaves with remote objects)
>> + *   or when there are too many full sheaves. On architectures supporting
>> + *   cmpxchg_double this is done by a lockless update of slab's freelist and
>> + *   counters, otherwise slab_lock is taken. This only needs to take the
>> + *   list_lock if it's a first free to a full slab, or when there are too many
>> + *   fully free slabs and some need to be discarded.
> 
> nit: "or when a slab becomes empty after the free"?
> because we don't check nr_partial before acquiring list_lock.
> 
> With that addressed,
> Reviewed-by: Harry Yoo <harry.yoo@...cle.com>

Good point, thanks!