The patch titled Subject: mm: use unique zsmalloc caches names has been added to the -mm mm-hotfixes-unstable branch. Its filename is mm-use-unique-zsmalloc-caches-names.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-use-unique-zsmalloc-caches-names.patch This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx> Subject: mm: use unique zsmalloc caches names Date: Thu, 5 Sep 2024 15:47:23 +0900 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 ... Link: https://lkml.kernel.org/r/20240905064736.2250735-1-senozhatsky@xxxxxxxxxxxx Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx> Cc: Minchan Kim <minchan@xxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/zsmalloc.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) --- a/mm/zsmalloc.c~mm-use-unique-zsmalloc-caches-names +++ a/mm/zsmalloc.c @@ -293,13 +293,17 @@ static void SetZsPageMovable(struct zs_p static int create_cache(struct zs_pool *pool) { - pool->handle_cachep = kmem_cache_create("zs_handle", ZS_HANDLE_SIZE, - 0, 0, NULL); + char name[32]; + + snprintf(name, sizeof(name), "zs_handle-%s", pool->name); + pool->handle_cachep = kmem_cache_create(name, ZS_HANDLE_SIZE, + 0, 0, NULL); if (!pool->handle_cachep) return 1; - pool->zspage_cachep = kmem_cache_create("zspage", sizeof(struct zspage), - 0, 0, NULL); + snprintf(name, sizeof(name), "zspage-%s", pool->name); + pool->zspage_cachep = kmem_cache_create(name, sizeof(struct zspage), + 0, 0, NULL); if (!pool->zspage_cachep) { kmem_cache_destroy(pool->handle_cachep); pool->handle_cachep = NULL; _ Patches currently in -mm which might be from senozhatsky@xxxxxxxxxxxx are mm-use-unique-zsmalloc-caches-names.patch lib-zstd-export-api-needed-for-dictionary-support.patch lib-lz4hc-export-lz4_resetstreamhc-symbol.patch lib-zstd-fix-null-deref-in-zstd_createcdict_advanced2.patch zram-introduce-custom-comp-backends-api.patch zram-add-lzo-and-lzorle-compression-backends-support.patch zram-add-lz4-compression-backend-support.patch zram-add-lz4hc-compression-backend-support.patch zram-add-zstd-compression-backend-support.patch zram-pass-estimated-src-size-hint-to-zstd.patch zram-add-zlib-compression-backend-support.patch zram-add-842-compression-backend-support.patch zram-check-that-backends-array-has-at-least-one-backend.patch zram-introduce-zcomp_params-structure.patch zram-recalculate-zstd-compression-params-once.patch zram-introduce-algorithm_params-device-attribute.patch zram-add-support-for-dict-comp-config.patch zram-introduce-zcomp_req-structure.patch zram-introduce-zcomp_ctx-structure.patch zram-move-immutable-comp-params-away-from-per-cpu-context.patch zram-add-dictionary-support-to-lz4.patch zram-add-dictionary-support-to-lz4hc.patch zram-add-dictionary-support-to-zstd-backend.patch documentation-zram-add-documentation-for-algorithm-parameters.patch documentation-zram-add-documentation-for-algorithm-parameters-fix.patch zram-support-priority-parameter-in-recompression.patch mm-kconfig-fixup-zsmalloc-configuration.patch