Currently, it is only possible to disable tcache system-wide, but it might be useful to disable it for a particular container while leaving it enabled for others, e.g. in case the container is known to generate tons of used-once page cache (backup).
This patch introduces memory.disable_cleancache per memcg knob. Writing 1 to it disables cleancache for the corresponding cgroup. Cleancache may be re-enabled by writing 0 to it. https://jira.sw.ru/browse/PSBM-34163 Signed-off-by: Vladimir Davydov <vdavy...@parallels.com> --- include/linux/memcontrol.h | 6 +++++ mm/cleancache.c | 10 ++++++-- mm/memcontrol.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 72 insertions(+), 2 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index ac3f16f0ee28..85a3b2182c9d 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -117,6 +117,7 @@ void mem_cgroup_iter_break(struct mem_cgroup *, struct mem_cgroup *); */ int mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec); bool mem_cgroup_low(struct mem_cgroup *root, struct mem_cgroup *memcg); +bool mem_cgroup_cleancache_disabled(struct page *page); int mem_cgroup_select_victim_node(struct mem_cgroup *memcg); unsigned long mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list); void mem_cgroup_update_lru_size(struct lruvec *, enum lru_list, int); @@ -333,6 +334,11 @@ static inline bool mem_cgroup_low(struct mem_cgroup *root, return false; } +static inline bool mem_cgroup_cleancache_disabled(struct page *page) +{ + return false; +} + static inline unsigned long mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru) { diff --git a/mm/cleancache.c b/mm/cleancache.c index a3308bcaa116..16fc1d7c90ae 100644 --- a/mm/cleancache.c +++ b/mm/cleancache.c @@ -15,6 +15,7 @@ #include <linux/fs.h> #include <linux/exportfs.h> #include <linux/mm.h> +#include <linux/memcontrol.h> #include <linux/debugfs.h> #include <linux/cleancache.h> @@ -227,8 +228,13 @@ void __cleancache_put_page(struct page *page) pool_id = page->mapping->host->i_sb->cleancache_poolid; if (pool_id >= 0 && cleancache_get_key(page->mapping->host, &key) >= 0) { - cleancache_ops->put_page(pool_id, key, page->index, page); - cleancache_puts++; + if (!mem_cgroup_cleancache_disabled(page)) { + cleancache_ops->put_page(pool_id, key, + page->index, page); + cleancache_puts++; + } else + cleancache_ops->invalidate_page(pool_id, key, + page->index); } } EXPORT_SYMBOL(__cleancache_put_page); diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 00cc66db5052..30782b37e2c2 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -326,6 +326,10 @@ struct mem_cgroup { /* For oom notifier event fd */ struct list_head oom_notify; +#ifdef CONFIG_CLEANCACHE + bool cleancache_disabled; +#endif + /* * Should we move charges of a task when a task is moved into this * mem_cgroup ? And what type of charges should we move ? @@ -1577,6 +1581,37 @@ bool mem_cgroup_low(struct mem_cgroup *root, struct mem_cgroup *memcg) return true; } +#ifdef CONFIG_CLEANCACHE +bool mem_cgroup_cleancache_disabled(struct page *page) +{ + struct mem_cgroup *memcg = NULL; + struct page_cgroup *pc; + bool ret = false; + + if (mem_cgroup_disabled()) + goto out; + + pc = lookup_page_cgroup(page); + if (!PageCgroupUsed(pc)) + goto out; + + lock_page_cgroup(pc); + if (!PageCgroupUsed(pc)) + goto out_unlock; + + for (memcg = pc->mem_cgroup; memcg; memcg = parent_mem_cgroup(memcg)) { + if (memcg->cleancache_disabled) { + ret = true; + break; + } + } +out_unlock: + unlock_page_cgroup(pc); +out: + return ret; +} +#endif + static bool __mem_cgroup_below_oom_guarantee(struct mem_cgroup *root, struct mem_cgroup *memcg) { @@ -5292,6 +5327,21 @@ static int mem_cgroup_oom_guarantee_write(struct cgroup *cont, return 0; } +#ifdef CONFIG_CLEANCACHE +static u64 mem_cgroup_disable_cleancache_read(struct cgroup *cgrp, + struct cftype *cft) +{ + return mem_cgroup_from_cont(cgrp)->cleancache_disabled; +} + +static int mem_cgroup_disable_cleancache_write(struct cgroup *cgrp, + struct cftype *cft, u64 val) +{ + mem_cgroup_from_cont(cgrp)->cleancache_disabled = !!val; + return 0; +} +#endif + static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg, unsigned long long *mem_limit, unsigned long long *memsw_limit) { @@ -6226,6 +6276,14 @@ static struct cftype mem_cgroup_files[] = { .read_seq_string = memcg_numa_stat_show, }, #endif +#ifdef CONFIG_CLEANCACHE + { + .name = "disable_cleancache", + .flags = CFTYPE_NOT_ON_ROOT, + .read_u64 = mem_cgroup_disable_cleancache_read, + .write_u64 = mem_cgroup_disable_cleancache_write, + }, +#endif #ifdef CONFIG_MEMCG_KMEM { .name = "kmem.limit_in_bytes", -- 2.1.4 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel
