mm, slub: don't create kmalloc-rcl caches with CONFIG_SLUB_TINY

Distinguishing kmalloc(__GFP_RECLAIMABLE) can help against fragmentation
by grouping pages by mobility, but on tiny systems the extra memory
overhead of separate set of kmalloc-rcl caches will probably be worse,
and mobility grouping likely disabled anyway.

Thus with CONFIG_SLUB_TINY, don't create kmalloc-rcl caches and use the
regular ones.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Christoph Lameter <cl@linux.com>

diff --git a/include/linux/slab.h b/include/linux/slab.h
index 45efc6c553b826101da7855a4573dfe66c845ae4..ae2d19ec8467418d76709b0dfbfea0fe12c22cc5 100644 (file)
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -336,12 +336,17 @@ enum kmalloc_cache_type {
 #endif
 #ifndef CONFIG_MEMCG_KMEM
        KMALLOC_CGROUP = KMALLOC_NORMAL,
-#else
-       KMALLOC_CGROUP,
 #endif
+#ifdef CONFIG_SLUB_TINY
+       KMALLOC_RECLAIM = KMALLOC_NORMAL,
+#else
        KMALLOC_RECLAIM,
+#endif
 #ifdef CONFIG_ZONE_DMA
        KMALLOC_DMA,
+#endif
+#ifdef CONFIG_MEMCG_KMEM
+       KMALLOC_CGROUP,
 #endif
        NR_KMALLOC_TYPES
 };

diff --git a/mm/slab_common.c b/mm/slab_common.c
index af0f370fe7a28a492462af700aa03c474bef606e..012fc75d3ffa23350fbdf32c0b646862f17b753e 100644 (file)
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -773,10 +773,16 @@ EXPORT_SYMBOL(kmalloc_size_roundup);
 #define KMALLOC_CGROUP_NAME(sz)
 #endif
 
+#ifndef CONFIG_SLUB_TINY
+#define KMALLOC_RCL_NAME(sz)   .name[KMALLOC_RECLAIM] = "kmalloc-rcl-" #sz,
+#else
+#define KMALLOC_RCL_NAME(sz)
+#endif
+
 #define INIT_KMALLOC_INFO(__size, __short_size)                        \
 {                                                              \
        .name[KMALLOC_NORMAL]  = "kmalloc-" #__short_size,      \
-       .name[KMALLOC_RECLAIM] = "kmalloc-rcl-" #__short_size,  \
+       KMALLOC_RCL_NAME(__short_size)                          \
        KMALLOC_CGROUP_NAME(__short_size)                       \
        KMALLOC_DMA_NAME(__short_size)                          \
        .size = __size,                                         \
@@ -862,7 +868,7 @@ void __init setup_kmalloc_cache_index_table(void)
 static void __init
 new_kmalloc_cache(int idx, enum kmalloc_cache_type type, slab_flags_t flags)
 {
-       if (type == KMALLOC_RECLAIM) {
+       if ((KMALLOC_RECLAIM != KMALLOC_NORMAL) && (type == KMALLOC_RECLAIM)) {
                flags |= SLAB_RECLAIM_ACCOUNT;
        } else if (IS_ENABLED(CONFIG_MEMCG_KMEM) && (type == KMALLOC_CGROUP)) {
                if (mem_cgroup_kmem_disabled()) {