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-<size> 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
Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
---
mm/slab.c | 3 ++-
mm/slab.h | 1 +
mm/slab_common.c | 5 +++++
3 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/mm/slab.c b/mm/slab.c
index a95fd4fed0a8..ede31b59bb9f 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1293,7 +1293,8 @@ 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(
+ get_kmalloc_cache_name(INDEX_NODE),
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 de6579dc362c..5708c548c6f7 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -78,6 +78,7 @@ unsigned long calculate_alignment(unsigned long flags,
/* Kmalloc array related functions */
void setup_kmalloc_cache_index_table(void);
void create_kmalloc_caches(unsigned long);
+const char *get_kmalloc_cache_name(int index);
/* Find the kmalloc slab corresponding for a certain size */
struct kmem_cache *kmalloc_slab(size_t, gfp_t);
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 1dfc209431f2..36a8547de699 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -937,6 +937,11 @@ static struct {
{"kmalloc-67108864", 67108864}
};
+const char *get_kmalloc_cache_name(int index)
+{
+ return kmalloc_info[index].name;
+}
+
/*
* Patch up the size_index table if we have strange large alignment
* requirements for the kmalloc array. This is only the case for
--
2.11.0
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