[PATCH 04/12] mm, slub: retain no free slabs on partial list with CONFIG_SLUB_TINY

From: Vlastimil Babka
Date: Mon Nov 21 2022 - 12:12:30 EST


SLUB will leave a number of slabs on the partial list even if they are
empty, to avoid some slab freeing and reallocation. The goal of
CONFIG_SLUB_TINY is to minimize memory overhead, so set the limits to 0
for immediate slab page freeing.

Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
---
mm/slub.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/mm/slub.c b/mm/slub.c
index ab085aa2f1f0..917b79278bad 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -241,6 +241,7 @@ static inline bool kmem_cache_has_cpu_partial(struct kmem_cache *s)
/* Enable to log cmpxchg failures */
#undef SLUB_DEBUG_CMPXCHG

+#ifndef CONFIG_SLUB_TINY
/*
* Minimum number of partial slabs. These will be left on the partial
* lists even if they are empty. kmem_cache_shrink may reclaim them.
@@ -253,6 +254,10 @@ static inline bool kmem_cache_has_cpu_partial(struct kmem_cache *s)
* sort the partial list by the number of objects in use.
*/
#define MAX_PARTIAL 10
+#else
+#define MIN_PARTIAL 0
+#define MAX_PARTIAL 0
+#endif

#define DEBUG_DEFAULT_FLAGS (SLAB_CONSISTENCY_CHECKS | SLAB_RED_ZONE | \
SLAB_POISON | SLAB_STORE_USER)
--
2.38.1