Re: [RFC 10/26] mm, slub: do initial checks in ___slab_alloc() with irqs enabled

From: Vlastimil Babka
Date: Tue Jun 08 2021 - 08:13:29 EST


On 5/25/21 3:04 PM, Mel Gorman wrote:
> On Tue, May 25, 2021 at 01:39:30AM +0200, Vlastimil Babka wrote:
>> As another step of shortening irq disabled sections in ___slab_alloc(), don't
>> disable irqs until doing initial checks if there is a cached percpu slab and
>> it's suitable for our allocation.
>>
>> Now we have to recheck c->page after actually disabling irqs as an allocation
>> in irq might have replaced it.
>>
>> Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
>
> Minor nit only -- consider adding a comment at the new_slab label that
> IRQs must be disabled already.

Good point, will use lockdep_assert_irqs_disabled() as that's a functional comment.

> Acked-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>

Thanks.