From: Vlastimil Babka <vbabka@suse.cz>
Date: Tue, 8 Jun 2021 01:19:03 +0200
Subject: mm, slub: remove redundant unfreeze_partials() from put_cpu_partial()
Git-commit: 976b805c782a57256e08aeaab45a64536b8887cf
Patch-mainline: v5.15-rc1
References: bsc#1189998

Commit d6e0b7fa1186 ("slub: make dead caches discard free slabs immediately")
introduced cpu partial flushing for kmemcg caches, based on setting the target
cpu_partial to 0 and adding a flushing check in put_cpu_partial().
This code that sets cpu_partial to 0 was later moved by c9fc586403e7 ("slab:
introduce __kmemcg_cache_deactivate()") and ultimately removed by 9855609bde03
("mm: memcg/slab: use a single set of kmem_caches for all accounted
allocations"). However the check and flush in put_cpu_partial() was never
removed, although it's effectively a dead code. So this patch removes it.

Note that d6e0b7fa1186 also added preempt_disable()/enable() to
unfreeze_partials() which could be thus also considered unnecessary. But
further patches will rely on it, so keep it.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
---
 mm/slub.c |    7 -------
 1 file changed, 7 deletions(-)

--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2466,13 +2466,6 @@ static void put_cpu_partial(struct kmem_
 
 	} while (this_cpu_cmpxchg(s->cpu_slab->partial, oldpage, page)
 								!= oldpage);
-	if (unlikely(!slub_cpu_partial(s))) {
-		unsigned long flags;
-
-		local_irq_save(flags);
-		unfreeze_partials(s, this_cpu_ptr(s->cpu_slab));
-		local_irq_restore(flags);
-	}
 	preempt_enable();
 #endif	/* CONFIG_SLUB_CPU_PARTIAL */
 }