From af3b5f8764a270165195d8b9520d913a268c0062 Mon Sep 17 00:00:00 2001 From: Vlastimil Babka Date: Wed, 22 Feb 2017 15:41:05 -0800 Subject: [PATCH] mm, slab: rename kmalloc-node cache to kmalloc- SLAB as part of its bootstrap pre-creates one kmalloc cache that can fit the kmem_cache_node management structure, and puts it into the generic kmalloc cache array (e.g. for 128b objects). The name of this cache is "kmalloc-node", which is confusing for readers of /proc/slabinfo as the cache is used for generic allocations (and not just the kmem_cache_node struct) and it appears as the kmalloc-128 cache is missing. An easy solution is to use the kmalloc- name when pre-creating the cache, which we can get from the kmalloc_info array. Example /proc/slabinfo before the patch: ... kmalloc-256 1647 1984 256 16 1 : tunables 120 60 8 : slabdata 124 124 828 kmalloc-192 1974 1974 192 21 1 : tunables 120 60 8 : slabdata 94 94 133 kmalloc-96 1332 1344 128 32 1 : tunables 120 60 8 : slabdata 42 42 219 kmalloc-64 2505 5952 64 64 1 : tunables 120 60 8 : slabdata 93 93 715 kmalloc-32 4278 4464 32 124 1 : tunables 120 60 8 : slabdata 36 36 346 kmalloc-node 1352 1376 128 32 1 : tunables 120 60 8 : slabdata 43 43 53 kmem_cache 132 147 192 21 1 : tunables 120 60 8 : slabdata 7 7 0 After the patch: ... kmalloc-256 1672 2160 256 16 1 : tunables 120 60 8 : slabdata 135 135 807 kmalloc-192 1992 2016 192 21 1 : tunables 120 60 8 : slabdata 96 96 203 kmalloc-96 1159 1184 128 32 1 : tunables 120 60 8 : slabdata 37 37 116 kmalloc-64 2561 4864 64 64 1 : tunables 120 60 8 : slabdata 76 76 785 kmalloc-32 4253 4340 32 124 1 : tunables 120 60 8 : slabdata 35 35 270 kmalloc-128 1256 1280 128 32 1 : tunables 120 60 8 : slabdata 40 40 39 kmem_cache 125 147 192 21 1 : tunables 120 60 8 : slabdata 7 7 0 [vbabka@suse.cz: export the whole kmalloc_info structure instead of just a name accessor, per Christoph Lameter] Link: http://lkml.kernel.org/r/54e80303-b814-4232-66d4-95b34d3eb9d0@suse.cz Link: http://lkml.kernel.org/r/20170203181008.24898-1-vbabka@suse.cz Signed-off-by: Vlastimil Babka Reviewed-by: Matthew Wilcox Cc: Joonsoo Kim Cc: David Rientjes Cc: Pekka Enberg Cc: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/slab.c | 3 ++- mm/slab.h | 6 ++++++ mm/slab_common.c | 5 +---- 3 files changed, 9 insertions(+), 5 deletions(-) diff --git a/mm/slab.c b/mm/slab.c index 4f2ec6b..be977ef6 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -1288,7 +1288,8 @@ void __init kmem_cache_init(void) * Initialize the caches that provide memory for the kmem_cache_node * structures first. Without this, further allocations will bug. */ - kmalloc_caches[INDEX_NODE] = create_kmalloc_cache("kmalloc-node", + kmalloc_caches[INDEX_NODE] = create_kmalloc_cache( + kmalloc_info[INDEX_NODE].name, kmalloc_size(INDEX_NODE), ARCH_KMALLOC_FLAGS); slab_state = PARTIAL_NODE; setup_kmalloc_cache_index_table(); diff --git a/mm/slab.h b/mm/slab.h index de6579d..2fa8243 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -71,6 +71,12 @@ extern struct list_head slab_caches; /* The slab cache that manages slab cache information */ extern struct kmem_cache *kmem_cache; +/* A table of kmalloc cache names and sizes */ +extern const struct kmalloc_info_struct { + const char *name; + unsigned long size; +} kmalloc_info[]; + unsigned long calculate_alignment(unsigned long flags, unsigned long align, unsigned long size); diff --git a/mm/slab_common.c b/mm/slab_common.c index 36a263e..f266b0d 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -915,10 +915,7 @@ struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags) * kmalloc_index() supports up to 2^26=64MB, so the final entry of the table is * kmalloc-67108864. */ -static struct { - const char *name; - unsigned long size; -} const kmalloc_info[] __initconst = { +const struct kmalloc_info_struct kmalloc_info[] __initconst = { {NULL, 0}, {"kmalloc-96", 96}, {"kmalloc-192", 192}, {"kmalloc-8", 8}, {"kmalloc-16", 16}, {"kmalloc-32", 32}, -- 2.7.4