linux-stable.git/include/linux/memcontrol.h, branch v6.11.2

mm: memcg: add cacheline padding after lruvec in mem_cgroup_per_node

2024-07-26T21:33:09+00:00

Oliver Sand reported a performance regression caused by commit
98c9daf5ae6b ("mm: memcg: guard memcg1-specific members of struct
mem_cgroup_per_node"), which puts some fields of the mem_cgroup_per_node
structure under the CONFIG_MEMCG_V1 config option.  Apparently it causes a
false cache sharing between lruvec and lru_zone_size members of the
structure.  Fix it by adding an explicit padding after the lruvec member.

Even though the padding is not required with CONFIG_MEMCG_V1 set, it seems
like the introduced memory overhead is not significant enough to warrant
another divergence in the mem_cgroup_per_node layout, so the padding is
added unconditionally.

Link: https://lkml.kernel.org/r/20240723171244.747521-1-roman.gushchin@linux.dev
Fixes: 98c9daf5ae6b ("mm: memcg: guard memcg1-specific members of struct mem_cgroup_per_node")
Signed-off-by: Roman Gushchin 
Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-lkp/202407121335.31a10cb6-oliver.sang@intel.com
Tested-by: Oliver Sang 
Acked-by: Shakeel Butt 
Cc: Johannes Weiner 
Cc: Michal Hocko 
Cc: Muchun Song 
Cc: Roman Gushchin 
Signed-off-by: Andrew Morton

mm: remove CONFIG_MEMCG_KMEM

2024-07-10T19:14:54+00:00

CONFIG_MEMCG_KMEM used to be a user-visible option for whether slab
tracking is enabled.  It has been default-enabled and equivalent to
CONFIG_MEMCG for almost a decade.  We've only grown more kernel memory
accounting sites since, and there is no imaginable cgroup usecase going
forward that wants to track user pages but not the multitude of
user-drivable kernel allocations.

Link: https://lkml.kernel.org/r/20240701153148.452230-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner 
Acked-by: Roman Gushchin 
Acked-by: Michal Hocko 
Acked-by: Shakeel Butt 
Acked-by: David Hildenbrand 
Cc: Muchun Song 
Signed-off-by: Andrew Morton

mm: memcg: add cache line padding to mem_cgroup_per_node

2024-07-10T19:14:54+00:00

Memcg v1-specific fields serve a buffer function between read-mostly and
update often parts of the mem_cgroup_per_node structure.  If
CONFIG_MEMCG_V1 is not set and these fields are not present, an explicit
cacheline padding is needed.

Link: https://lkml.kernel.org/r/20240701185932.704807-2-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin 
Suggested-by: Shakeel Butt 
Acked-by: Shakeel Butt 
Cc: Johannes Weiner 
Cc: Michal Hocko 
Cc: Muchun Song 
Signed-off-by: Andrew Morton

mm: memcg: drop obsolete cache line padding in struct mem_cgroup

2024-07-10T19:14:53+00:00

After the grouping of the cgroup v1-related fields and the corresponding
reorganization of the struct mem_cgroup, the existing cache line padding
doesn't make much sense anymore.  Let's drop it for now and put back to
new places, if necessary.

Link: https://lkml.kernel.org/r/20240701185932.704807-1-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin 
Suggested-by: Shakeel Butt 
Acked-by: Shakeel Butt 
Cc: Johannes Weiner 
Cc: Michal Hocko 
Cc: Muchun Song 
Signed-off-by: Andrew Morton

mm: memcg: put struct task_struct::in_user_fault under CONFIG_MEMCG_V1

2024-07-05T01:05:57+00:00

The struct task_struct's in_user_fault member is not used by the cgroup
v2's memory controller, so it can be put under the CONFIG_MEMCG_V1 config
option.  To do so, mem_cgroup_enter_user_fault() and
mem_cgroup_exit_user_fault() are moved under the CONFIG_MEMCG_V1 option as
well.

Link: https://lkml.kernel.org/r/20240628210317.272856-10-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin 
Acked-by: Shakeel Butt 
Cc: Johannes Weiner 
Cc: Michal Hocko 
Cc: Muchun Song 
Signed-off-by: Andrew Morton

mm: memcg: guard memcg1-specific members of struct mem_cgroup_per_node

2024-07-05T01:05:57+00:00

Put memcg1-specific members of struct mem_cgroup_per_node under the
CONFIG_MEMCG_V1 config option.

Link: https://lkml.kernel.org/r/20240628210317.272856-8-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin 
Acked-by: Shakeel Butt 
Cc: Johannes Weiner 
Cc: Michal Hocko 
Cc: Muchun Song 
Signed-off-by: Andrew Morton

mm: memcg: put memcg1-specific struct mem_cgroup's members under CONFIG_MEMCG_V1

2024-07-05T01:05:56+00:00

Put memcg1-specific members of struct mem_cgroup under the CONFIG_MEMCG_V1
config option.  Also group them close to the end of struct mem_cgroup just
before the dynamic per-node part.

Link: https://lkml.kernel.org/r/20240628210317.272856-7-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin 
Acked-by: Shakeel Butt 
Cc: Johannes Weiner 
Cc: Michal Hocko 
Cc: Muchun Song 
Signed-off-by: Andrew Morton

mm: memcg: factor out legacy socket memory accounting code

2024-07-05T01:05:55+00:00

Move out the legacy cgroup v1 socket memory accounting code into
mm/memcontrol-v1.c.

This commit introduces three new functions: memcg1_tcpmem_active(),
memcg1_charge_skmem() and memcg1_uncharge_skmem(), which contain all
cgroup v1-specific code and become trivial if CONFIG_MEMCG_V1 isn't set.

Note, that !!memcg->tcpmem_pressure check in
mem_cgroup_under_socket_pressure() can't be easily moved into
memcontrol-v1.h without including memcontrol-v1.h from memcontrol.h which
isn't a good idea, so it's better to just #ifdef it.

Link: https://lkml.kernel.org/r/20240628210317.272856-3-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin 
Acked-by: Shakeel Butt 
Cc: Johannes Weiner 
Cc: Michal Hocko 
Cc: Muchun Song 
Signed-off-by: Andrew Morton

mm: memcg: put cgroup v1-specific code under a config option

2024-07-05T01:05:54+00:00

Put legacy cgroup v1 memory controller code under a new CONFIG_MEMCG_V1
config option.  The option is turned off by default.  Nobody except those
who are still using cgroup v1 should turn it on.

If the option is not set, memory controller can still be mounted under
cgroup v1, but none of memcg-specific control files are present.

Please note, that not all cgroup v1's memory controller code is guarded
yet (but most of it), it's a subject for some follow-up work.

Thanks to Michal Hocko for providing a better Kconfig option description.

[roman.gushchin@linux.dev: better config option description provided by Michal]
  Link: https://lkml.kernel.org/r/ZnxXNtvqllc9CDoo@google.com
Link: https://lkml.kernel.org/r/20240625005906.106920-14-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin 
Acked-by: Michal Hocko 
Acked-by: Shakeel Butt 
Cc: Johannes Weiner 
Cc: Matthew Wilcox (Oracle) 
Cc: Muchun Song 
Signed-off-by: Andrew Morton

mm: memcg: group cgroup v1 memcg related declarations

2024-07-05T01:05:54+00:00

Group all cgroup v1-related declarations at the end of memcontrol.h and
mm/memcontrol-v1.h with an intention to put them all together under a
config option later on.  It should make things easier to follow and
maintain too.

Link: https://lkml.kernel.org/r/20240625005906.106920-13-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin 
Acked-by: Michal Hocko 
Acked-by: Shakeel Butt 
Cc: Johannes Weiner 
Cc: Matthew Wilcox (Oracle) 
Cc: Muchun Song 
Signed-off-by: Andrew Morton