On 2023/10/27 23:18, Vlastimil Babka wrote:
> On 10/24/23 11:33, chengming.zhou@xxxxxxxxx wrote:
>> From: Chengming Zhou <zhouchengming@xxxxxxxxxxxxx>
>>
>> Now the partial slub will be frozen when taken out of node partial list,
>
> partially empty slab
>
>> so the __slab_free() will know from "was_frozen" that the partial slab
>> is not on node partial list and is used by one kmem_cache_cpu.
>
> ... is a cpu or cpu partial slab of some cpu.
>
>> But we will change this, make partial slabs leave the node partial list
>> with unfrozen state, so we need to change __slab_free() to use the new
>> slab_test_node_partial() we just introduced.
>>
>> Signed-off-by: Chengming Zhou <zhouchengming@xxxxxxxxxxxxx>
>> ---
>> mm/slub.c | 11 +++++++++++
>> 1 file changed, 11 insertions(+)
>>
>> diff --git a/mm/slub.c b/mm/slub.c
>> index 3fad4edca34b..f568a32d7332 100644
>> --- a/mm/slub.c
>> +++ b/mm/slub.c
>> @@ -3610,6 +3610,7 @@ static void __slab_free(struct kmem_cache *s, struct slab *slab,
>> unsigned long counters;
>> struct kmem_cache_node *n = NULL;
>> unsigned long flags;
>> + bool on_node_partial;
>>
>> stat(s, FREE_SLOWPATH);
>>
>> @@ -3657,6 +3658,7 @@ static void __slab_free(struct kmem_cache *s, struct slab *slab,
>> */
>> spin_lock_irqsave(&n->list_lock, flags);
>>
>> + on_node_partial = slab_test_node_partial(slab);
>> }
>> }
>>
>> @@ -3685,6 +3687,15 @@ static void __slab_free(struct kmem_cache *s, struct slab *slab,
>> return;
>> }
>>
>> + /*
>> + * This slab was partial but not on the per-node partial list,
>
> This slab was partially empty ...
>
> Otherwise LGTM!
Ok, will fix.
Thanks!
>
>> + * in which case we shouldn't manipulate its list, just return.
>> + */
>> + if (prior && !on_node_partial) {
>> + spin_unlock_irqrestore(&n->list_lock, flags);
>> + return;
>> + }
>> +
>> if (unlikely(!new.inuse && n->nr_partial >= s->min_partial))
>> goto slab_empty;
>>
>
