Re: [linux-next:master] [mm, slab] 298cdbf5f7: will-it-scale.per_process_ops 6.3% regression

On 5/14/26 18:00, Vlastimil Babka (SUSE) wrote:
> On 5/14/26 16:45, Vlastimil Babka (SUSE) wrote:
>> On 5/11/26 16:45, kernel test robot wrote:
>>> 
>>> 
>>> Hello,
>>> 
>>> kernel test robot noticed a 6.3% regression of will-it-scale.per_process_ops on:
>> 
>> Yay for an optimization that was supposed to have no tradeoffs :)
> 
> Does this help? I don't expect much, but perhaps...

And a separate measurement with this on top of the previous one, plase?
It's just that __slab_free() would have been adding to tail so let's try it
too.
 
From 8fba1377797478a945d97ad6163021d95ac7665c Mon Sep 17 00:00:00 2001
From: "Vlastimil Babka (SUSE)" <[email protected]>
Date: Thu, 14 May 2026 18:00:52 +0200
Subject: [PATCH] mm, slab: ADD_TO_TAIL in __refill_objects_node

---
 mm/slub.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/slub.c b/mm/slub.c
index 0cc6c88f11e3..35e574e94538 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -7193,7 +7193,7 @@ __refill_objects_node(struct kmem_cache *s, void **p, gfp_t gfp, unsigned int mi
 		list_for_each_entry_safe(slab, slab2, &pc.slabs, slab_list) {
 
 			list_del(&slab->slab_list);
-			add_partial(n, slab, ADD_TO_HEAD);
+			add_partial(n, slab, ADD_TO_TAIL);
 		}
 
 		spin_unlock_irqrestore(&n->list_lock, flags);
-- 
2.54.0