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...

This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------ From: Sergey Senozhatsky senozhatsky@chromium.org 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@chromium.org Signed-off-by: Sergey Senozhatsky senozhatsky@chromium.org Cc: Minchan Kim minchan@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

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@chromium.org 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