From e93d4166b40a84df83c4d5cb4c709d022808ef9b Mon Sep 17 00:00:00 2001 From: Roman Gushchin Date: Mon, 24 Jun 2024 17:59:05 -0700 Subject: [PATCH] mm: memcg: put cgroup v1-specific code under a config option 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 --- include/linux/memcontrol.h | 6 +++--- init/Kconfig | 17 +++++++++++++++++ mm/Makefile | 3 ++- mm/memcontrol-v1.h | 21 ++++++++++++++++++++- mm/memcontrol.c | 10 +++++++--- 5 files changed, 49 insertions(+), 8 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index a70d64ed04f5..796cfa842346 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -1851,7 +1851,7 @@ static inline bool mem_cgroup_zswap_writeback_enabled(struct mem_cgroup *memcg) /* Cgroup v1-related declarations */ -#ifdef CONFIG_MEMCG +#ifdef CONFIG_MEMCG_V1 unsigned long memcg1_soft_limit_reclaim(pg_data_t *pgdat, int order, gfp_t gfp_mask, unsigned long *total_scanned); @@ -1883,7 +1883,7 @@ static inline void mem_cgroup_unlock_pages(void) rcu_read_unlock(); } -#else /* CONFIG_MEMCG */ +#else /* CONFIG_MEMCG_V1 */ static inline unsigned long memcg1_soft_limit_reclaim(pg_data_t *pgdat, int order, gfp_t gfp_mask, @@ -1922,6 +1922,6 @@ static inline bool mem_cgroup_oom_synchronize(bool wait) return false; } -#endif /* CONFIG_MEMCG */ +#endif /* CONFIG_MEMCG_V1 */ #endif /* _LINUX_MEMCONTROL_H */ diff --git a/init/Kconfig b/init/Kconfig index febdea2afc3b..aca0ae9be04f 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -969,6 +969,23 @@ config MEMCG help Provides control over the memory footprint of tasks in a cgroup. +config MEMCG_V1 + bool "Legacy cgroup v1 memory controller" + depends on MEMCG + default n + help + Legacy cgroup v1 memory controller which has been deprecated by + cgroup v2 implementation. The v1 is there for legacy applications + which haven't migrated to the new cgroup v2 interface yet. If you + do not have any such application then you are completely fine leaving + this option disabled. + + Please note that feature set of the legacy memory controller is likely + going to shrink due to deprecation process. New deployments with v1 + controller are highly discouraged. + + San N is unsure. + config MEMCG_KMEM bool depends on MEMCG diff --git a/mm/Makefile b/mm/Makefile index 124d4dea2035..d2915f8c9dc0 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -96,7 +96,8 @@ obj-$(CONFIG_NUMA) += memory-tiers.o obj-$(CONFIG_DEVICE_MIGRATION) += migrate_device.o obj-$(CONFIG_TRANSPARENT_HUGEPAGE) += huge_memory.o khugepaged.o obj-$(CONFIG_PAGE_COUNTER) += page_counter.o -obj-$(CONFIG_MEMCG) += memcontrol.o memcontrol-v1.o vmpressure.o +obj-$(CONFIG_MEMCG_V1) += memcontrol-v1.o +obj-$(CONFIG_MEMCG) += memcontrol.o vmpressure.o ifdef CONFIG_SWAP obj-$(CONFIG_MEMCG) += swap_cgroup.o endif diff --git a/mm/memcontrol-v1.h b/mm/memcontrol-v1.h index 31522b1c174d..72f0e15a939d 100644 --- a/mm/memcontrol-v1.h +++ b/mm/memcontrol-v1.h @@ -70,7 +70,7 @@ unsigned long memcg_page_state_local_output(struct mem_cgroup *memcg, int item); int memory_stat_show(struct seq_file *m, void *v); /* Cgroup v1-specific declarations */ - +#ifdef CONFIG_MEMCG_V1 void memcg1_remove_from_trees(struct mem_cgroup *memcg); static inline void memcg1_soft_limit_reset(struct mem_cgroup *memcg) @@ -105,4 +105,23 @@ void memcg1_stat_format(struct mem_cgroup *memcg, struct seq_buf *s); extern struct cftype memsw_files[]; extern struct cftype mem_cgroup_legacy_files[]; +#else /* CONFIG_MEMCG_V1 */ + +static inline void memcg1_remove_from_trees(struct mem_cgroup *memcg) {} +static inline void memcg1_soft_limit_reset(struct mem_cgroup *memcg) {} +static inline bool memcg1_wait_acct_move(struct mem_cgroup *memcg) { return false; } +static inline void memcg1_css_offline(struct mem_cgroup *memcg) {} + +static inline bool memcg1_oom_prepare(struct mem_cgroup *memcg, bool *locked) { return true; } +static inline void memcg1_oom_finish(struct mem_cgroup *memcg, bool locked) {} +static inline void memcg1_oom_recover(struct mem_cgroup *memcg) {} + +static inline void memcg1_check_events(struct mem_cgroup *memcg, int nid) {} + +static inline void memcg1_stat_format(struct mem_cgroup *memcg, struct seq_buf *s) {} + +extern struct cftype memsw_files[]; +extern struct cftype mem_cgroup_legacy_files[]; +#endif /* CONFIG_MEMCG_V1 */ + #endif /* __MM_MEMCONTROL_V1_H */ diff --git a/mm/memcontrol.c b/mm/memcontrol.c index b47c00f60332..53a8491634b9 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4398,18 +4398,20 @@ struct cgroup_subsys memory_cgrp_subsys = { .css_free = mem_cgroup_css_free, .css_reset = mem_cgroup_css_reset, .css_rstat_flush = mem_cgroup_css_rstat_flush, - .can_attach = memcg1_can_attach, #if defined(CONFIG_LRU_GEN) || defined(CONFIG_MEMCG_KMEM) .attach = mem_cgroup_attach, #endif - .cancel_attach = memcg1_cancel_attach, - .post_attach = memcg1_move_task, #ifdef CONFIG_MEMCG_KMEM .fork = mem_cgroup_fork, .exit = mem_cgroup_exit, #endif .dfl_cftypes = memory_files, +#ifdef CONFIG_MEMCG_V1 + .can_attach = memcg1_can_attach, + .cancel_attach = memcg1_cancel_attach, + .post_attach = memcg1_move_task, .legacy_cftypes = mem_cgroup_legacy_files, +#endif .early_init = 0, }; @@ -5581,7 +5583,9 @@ static int __init mem_cgroup_swap_init(void) return 0; WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys, swap_files)); +#ifdef CONFIG_MEMCG_V1 WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys, memsw_files)); +#endif #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP) WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys, zswap_files)); #endif