Commit fe2cce15 authored by Vlastimil Babka's avatar Vlastimil Babka Committed by Linus Torvalds
Browse files

mm, slub: remove slub_memcg_sysfs boot param and CONFIG_SLUB_MEMCG_SYSFS_ON 

The boot param and config determine the value of memcg_sysfs_enabled,
which is unused since commit 10befea9 ("mm: memcg/slab: use a single
set of kmem_caches for all allocations") as there are no per-memcg kmem
caches anymore.

Link: https://lkml.kernel.org/r/20210127124745.7928-1-vbabka@suse.cz


Signed-off-by: default avatarVlastimil Babka <vbabka@suse.cz>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Acked-by: default avatarRoman Gushchin <guro@fb.com>
Acked-by: default avatarDavid Rientjes <rientjes@google.com>
Reviewed-by: default avatarMiaohe Lin <linmiaohe@huawei.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d930ff03

Documentation/admin-guide/kernel-parameters.txt

+0 −8
Original line number Diff line number Diff line
@@ -4899,14 +4899,6 @@ 
			last alloc / free. For more information see

			Documentation/vm/slub.rst.



	slub_memcg_sysfs=	[MM, SLUB]

			Determines whether to enable sysfs directories for

			memory cgroup sub-caches. 1 to enable, 0 to disable.

			The default is determined by CONFIG_SLUB_MEMCG_SYSFS_ON.

			Enabling this can lead to a very high number of	debug

			directories and files being created under

			/sys/kernel/slub.



	slub_max_order= [MM, SLUB]

			Determines the maximum allowed order for slabs.

			A high setting may cause OOMs due to memory

init/Kconfig

+0 −14
Original line number Diff line number Diff line
@@ -1861,20 +1861,6 @@ config SLUB_DEBUG 
	  SLUB sysfs support. /sys/slab will not exist and there will be

	  no support for cache validation etc.



config SLUB_MEMCG_SYSFS_ON

	default n

	bool "Enable memcg SLUB sysfs support by default" if EXPERT

	depends on SLUB && SYSFS && MEMCG

	help

	  SLUB creates a directory under /sys/kernel/slab for each

	  allocation cache to host info and debug files. If memory

	  cgroup is enabled, each cache can have per memory cgroup

	  caches. SLUB can create the same sysfs directories for these

	  caches under /sys/kernel/slab/CACHE/cgroup but it can lead

	  to a very high number of debug files being created. This is

	  controlled by slub_memcg_sysfs boot parameter and this

	  config option determines the parameter's default value.



config COMPAT_BRK

	bool "Disable heap randomization"

	default y

mm/slub.c

+0 −16
Original line number Diff line number Diff line
@@ -4943,22 +4943,6 @@ enum slab_stat_type { 
#define SO_OBJECTS	(1 << SL_OBJECTS)

#define SO_TOTAL	(1 << SL_TOTAL)



#ifdef CONFIG_MEMCG

static bool memcg_sysfs_enabled = IS_ENABLED(CONFIG_SLUB_MEMCG_SYSFS_ON);



static int __init setup_slub_memcg_sysfs(char *str)

{

	int v;



	if (get_option(&str, &v) > 0)

		memcg_sysfs_enabled = v;



	return 1;

}



__setup("slub_memcg_sysfs=", setup_slub_memcg_sysfs);

#endif



static ssize_t show_slab_objects(struct kmem_cache *s,

				 char *buf, unsigned long flags)

{