Each zsmalloc pool maintains several named kmem-caches for
zs_handle-s and zspage-s. On a system with multiple zsmalloc
pools and CONFIG_DEBUG_VM this triggers kmem_cache_sanity_check():
kmem_cache of name 'zspage' already exists
WARNING: at mm/slab_common.c:108 do_kmem_cache_create_usercopy+0xb5/0x310
...
kmem_cache of name 'zs_handle' already exists
WARNING: at mm/slab_common.c:108 do_kmem_cache_create_usercopy+0xb5/0x310
...
We provide zram device name when init its zsmalloc pool, so we can
use that same name for zsmalloc caches and, hence, create unique
names that can easily be linked to zram device that has created
them.
So instead of having this
cat /proc/slabinfo
slabinfo - version: 2.1
zspage 46 46 ...
zs_handle 128 128 ...
zspage 34270 34270 ...
zs_handle 34816 34816 ...
zspage 0 0 ...
zs_handle 0 0 ...
We now have this
cat /proc/slabinfo
slabinfo - version: 2.1
zspage-zram2 46 46 ...
zs_handle-zram2 128 128 ...
zspage-zram0 34270 34270 ...
zs_handle-zram0 34816 34816 ...
zspage-zram1 0 0 ...
zs_handle-zram1 0 0 ...
Fixes: 2e40e163a25a ("zsmalloc: decouple handle and object")
Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
---
mm/zsmalloc.c | 23 +++++++++++++++++------
1 file changed, 17 insertions(+), 6 deletions(-)
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 73a3ec5b21ad..16a07def09c9 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -54,6 +54,7 @@
#include <linux/vmalloc.h>
#include <linux/preempt.h>
#include <linux/spinlock.h>
+#include <linux/sprintf.h>
#include <linux/shrinker.h>
#include <linux/types.h>
#include <linux/debugfs.h>
@@ -293,17 +294,27 @@ static void SetZsPageMovable(struct zs_pool *pool, struct zspage *zspage) {}
static int create_cache(struct zs_pool *pool)
{
- pool->handle_cachep = kmem_cache_create("zs_handle", ZS_HANDLE_SIZE,
- 0, 0, NULL);
+ char *name;
+
+ name = kasprintf(GFP_KERNEL, "zs_handle-%s", pool->name);
+ if (!name)
+ return -ENOMEM;
+ pool->handle_cachep = kmem_cache_create(name, ZS_HANDLE_SIZE,
+ 0, 0, NULL);
+ kfree(name);
if (!pool->handle_cachep)
- return 1;
+ return -EINVAL;
- pool->zspage_cachep = kmem_cache_create("zspage", sizeof(struct zspage),
- 0, 0, NULL);
+ name = kasprintf(GFP_KERNEL, "zspage-%s", pool->name);
+ if (!name)
+ return -ENOMEM;
+ pool->zspage_cachep = kmem_cache_create(name, sizeof(struct zspage),
+ 0, 0, NULL);
+ kfree(name);
if (!pool->zspage_cachep) {
kmem_cache_destroy(pool->handle_cachep);
pool->handle_cachep = NULL;
- return 1;
+ return -EINVAL;
}
return 0;
--
2.46.0.469.g59c65b2a67-goog
