* Andrea Righi <arighi@xxxxxxxxxxx> [2010-03-01 22:23:39]: > Infrastructure to account dirty pages per cgroup and add dirty limit > interfaces in the cgroupfs: > > - Direct write-out: memory.dirty_ratio, memory.dirty_bytes > > - Background write-out: memory.dirty_background_ratio, memory.dirty_background_bytes > > Signed-off-by: Andrea Righi <arighi@xxxxxxxxxxx> Look good, but yet to be tested from my side. > --- > include/linux/memcontrol.h | 77 ++++++++++- > mm/memcontrol.c | 336 ++++++++++++++++++++++++++++++++++++++++---- > 2 files changed, 384 insertions(+), 29 deletions(-) > > diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h > index 1f9b119..cc88b2e 100644 > --- a/include/linux/memcontrol.h > +++ b/include/linux/memcontrol.h > @@ -19,12 +19,50 @@ > > #ifndef _LINUX_MEMCONTROL_H > #define _LINUX_MEMCONTROL_H > + > +#include <linux/writeback.h> > #include <linux/cgroup.h> > + > struct mem_cgroup; > struct page_cgroup; > struct page; > struct mm_struct; > > +/* Cgroup memory statistics items exported to the kernel */ > +enum mem_cgroup_page_stat_item { > + MEMCG_NR_DIRTYABLE_PAGES, > + MEMCG_NR_RECLAIM_PAGES, > + MEMCG_NR_WRITEBACK, > + MEMCG_NR_DIRTY_WRITEBACK_PAGES, > +}; > + > +/* > + * Statistics for memory cgroup. > + */ > +enum mem_cgroup_stat_index { > + /* > + * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss. > + */ > + MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */ > + MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */ > + MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */ > + MEM_CGROUP_STAT_PGPGIN_COUNT, /* # of pages paged in */ > + MEM_CGROUP_STAT_PGPGOUT_COUNT, /* # of pages paged out */ > + MEM_CGROUP_STAT_EVENTS, /* sum of pagein + pageout for internal use */ > + MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */ > + MEM_CGROUP_STAT_SOFTLIMIT, /* decrements on each page in/out. > + used by soft limit implementation */ > + MEM_CGROUP_STAT_THRESHOLDS, /* decrements on each page in/out. > + used by threshold implementation */ > + MEM_CGROUP_STAT_FILE_DIRTY, /* # of dirty pages in page cache */ > + MEM_CGROUP_STAT_WRITEBACK, /* # of pages under writeback */ > + MEM_CGROUP_STAT_WRITEBACK_TEMP, /* # of pages under writeback using > + temporary buffers */ > + MEM_CGROUP_STAT_UNSTABLE_NFS, /* # of NFS unstable pages */ > + > + MEM_CGROUP_STAT_NSTATS, > +}; > + > #ifdef CONFIG_CGROUP_MEM_RES_CTLR > /* > * All "charge" functions with gfp_mask should use GFP_KERNEL or > @@ -117,6 +155,13 @@ extern void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, > extern int do_swap_account; > #endif > > +extern long mem_cgroup_dirty_ratio(void); > +extern unsigned long mem_cgroup_dirty_bytes(void); > +extern long mem_cgroup_dirty_background_ratio(void); > +extern unsigned long mem_cgroup_dirty_background_bytes(void); > + > +extern s64 mem_cgroup_page_stat(enum mem_cgroup_page_stat_item item); > + Docstyle comments for each function would be appreciated > static inline bool mem_cgroup_disabled(void) > { > if (mem_cgroup_subsys.disabled) > @@ -125,7 +170,8 @@ static inline bool mem_cgroup_disabled(void) > } > > extern bool mem_cgroup_oom_called(struct task_struct *task); > -void mem_cgroup_update_file_mapped(struct page *page, int val); Good to see you make generic use of this function > +void mem_cgroup_update_stat(struct page *page, > + enum mem_cgroup_stat_index idx, int val); > unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, > gfp_t gfp_mask, int nid, > int zid); > @@ -300,8 +346,8 @@ mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) > { > } > > -static inline void mem_cgroup_update_file_mapped(struct page *page, > - int val) > +static inline void mem_cgroup_update_stat(struct page *page, > + enum mem_cgroup_stat_index idx, int val) > { > } > > @@ -312,6 +358,31 @@ unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, > return 0; > } > > +static inline long mem_cgroup_dirty_ratio(void) > +{ > + return vm_dirty_ratio; > +} > + > +static inline unsigned long mem_cgroup_dirty_bytes(void) > +{ > + return vm_dirty_bytes; > +} > + > +static inline long mem_cgroup_dirty_background_ratio(void) > +{ > + return dirty_background_ratio; > +} > + > +static inline unsigned long mem_cgroup_dirty_background_bytes(void) > +{ > + return dirty_background_bytes; > +} > + > +static inline s64 mem_cgroup_page_stat(enum mem_cgroup_page_stat_item item) > +{ > + return -ENOMEM; > +} > + > #endif /* CONFIG_CGROUP_MEM_CONT */ > > #endif /* _LINUX_MEMCONTROL_H */ > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index a443c30..e74cf66 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -66,31 +66,16 @@ static int really_do_swap_account __initdata = 1; /* for remember boot option*/ > #define SOFTLIMIT_EVENTS_THRESH (1000) > #define THRESHOLDS_EVENTS_THRESH (100) > > -/* > - * Statistics for memory cgroup. > - */ > -enum mem_cgroup_stat_index { > - /* > - * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss. > - */ > - MEM_CGROUP_STAT_CACHE, /* # of pages charged as cache */ > - MEM_CGROUP_STAT_RSS, /* # of pages charged as anon rss */ > - MEM_CGROUP_STAT_FILE_MAPPED, /* # of pages charged as file rss */ > - MEM_CGROUP_STAT_PGPGIN_COUNT, /* # of pages paged in */ > - MEM_CGROUP_STAT_PGPGOUT_COUNT, /* # of pages paged out */ > - MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */ > - MEM_CGROUP_STAT_SOFTLIMIT, /* decrements on each page in/out. > - used by soft limit implementation */ > - MEM_CGROUP_STAT_THRESHOLDS, /* decrements on each page in/out. > - used by threshold implementation */ > - > - MEM_CGROUP_STAT_NSTATS, > -}; > - > struct mem_cgroup_stat_cpu { > s64 count[MEM_CGROUP_STAT_NSTATS]; > }; > > +/* Per cgroup page statistics */ > +struct mem_cgroup_page_stat { > + enum mem_cgroup_page_stat_item item; > + s64 value; > +}; > + > /* > * per-zone information in memory controller. > */ > @@ -157,6 +142,15 @@ struct mem_cgroup_threshold_ary { > static bool mem_cgroup_threshold_check(struct mem_cgroup *mem); > static void mem_cgroup_threshold(struct mem_cgroup *mem); > > +enum mem_cgroup_dirty_param { > + MEM_CGROUP_DIRTY_RATIO, > + MEM_CGROUP_DIRTY_BYTES, > + MEM_CGROUP_DIRTY_BACKGROUND_RATIO, > + MEM_CGROUP_DIRTY_BACKGROUND_BYTES, > + > + MEM_CGROUP_DIRTY_NPARAMS, > +}; > + > /* > * The memory controller data structure. The memory controller controls both > * page cache and RSS per cgroup. We would eventually like to provide > @@ -205,6 +199,9 @@ struct mem_cgroup { > > unsigned int swappiness; > > + /* control memory cgroup dirty pages */ > + unsigned long dirty_param[MEM_CGROUP_DIRTY_NPARAMS]; > + Could you mention what protects this field, is it the reclaim_lock? BTW, is unsigned long sufficient to represent dirty_param(s)? > /* set when res.limit == memsw.limit */ > bool memsw_is_minimum; > > @@ -1021,6 +1018,164 @@ static unsigned int get_swappiness(struct mem_cgroup *memcg) > return swappiness; > } > > +static unsigned long get_dirty_param(struct mem_cgroup *memcg, > + enum mem_cgroup_dirty_param idx) > +{ > + unsigned long ret; > + > + VM_BUG_ON(idx >= MEM_CGROUP_DIRTY_NPARAMS); > + spin_lock(&memcg->reclaim_param_lock); > + ret = memcg->dirty_param[idx]; > + spin_unlock(&memcg->reclaim_param_lock); Do we need a spinlock if we protect it using RCU? Is precise data very important? > + > + return ret; > +} > + > +long mem_cgroup_dirty_ratio(void) > +{ > + struct mem_cgroup *memcg; > + long ret = vm_dirty_ratio; > + > + if (mem_cgroup_disabled()) > + return ret; > + /* > + * It's possible that "current" may be moved to other cgroup while we > + * access cgroup. But precise check is meaningless because the task can > + * be moved after our access and writeback tends to take long time. > + * At least, "memcg" will not be freed under rcu_read_lock(). > + */ > + rcu_read_lock(); > + memcg = mem_cgroup_from_task(current); > + if (likely(memcg)) > + ret = get_dirty_param(memcg, MEM_CGROUP_DIRTY_RATIO); > + rcu_read_unlock(); > + > + return ret; > +} > + > +unsigned long mem_cgroup_dirty_bytes(void) > +{ > + struct mem_cgroup *memcg; > + unsigned long ret = vm_dirty_bytes; > + > + if (mem_cgroup_disabled()) > + return ret; > + rcu_read_lock(); > + memcg = mem_cgroup_from_task(current); > + if (likely(memcg)) > + ret = get_dirty_param(memcg, MEM_CGROUP_DIRTY_BYTES); > + rcu_read_unlock(); > + > + return ret; > +} > + > +long mem_cgroup_dirty_background_ratio(void) > +{ > + struct mem_cgroup *memcg; > + long ret = dirty_background_ratio; > + > + if (mem_cgroup_disabled()) > + return ret; > + rcu_read_lock(); > + memcg = mem_cgroup_from_task(current); > + if (likely(memcg)) > + ret = get_dirty_param(memcg, MEM_CGROUP_DIRTY_BACKGROUND_RATIO); > + rcu_read_unlock(); > + > + return ret; > +} > + > +unsigned long mem_cgroup_dirty_background_bytes(void) > +{ > + struct mem_cgroup *memcg; > + unsigned long ret = dirty_background_bytes; > + > + if (mem_cgroup_disabled()) > + return ret; > + rcu_read_lock(); > + memcg = mem_cgroup_from_task(current); > + if (likely(memcg)) > + ret = get_dirty_param(memcg, MEM_CGROUP_DIRTY_BACKGROUND_BYTES); > + rcu_read_unlock(); > + > + return ret; > +} > + > +static inline bool mem_cgroup_can_swap(struct mem_cgroup *memcg) > +{ > + return do_swap_account ? > + res_counter_read_u64(&memcg->memsw, RES_LIMIT) : Shouldn't you do a res_counter_read_u64(...) > 0 for readability? What happens if memcg->res, RES_LIMIT == memcg->memsw, RES_LIMIT? > + nr_swap_pages > 0; > +} > + > +static s64 mem_cgroup_get_local_page_stat(struct mem_cgroup *memcg, > + enum mem_cgroup_page_stat_item item) > +{ > + s64 ret; > + > + switch (item) { > + case MEMCG_NR_DIRTYABLE_PAGES: > + ret = res_counter_read_u64(&memcg->res, RES_LIMIT) - > + res_counter_read_u64(&memcg->res, RES_USAGE); > + /* Translate free memory in pages */ > + ret >>= PAGE_SHIFT; > + ret += mem_cgroup_read_stat(memcg, LRU_ACTIVE_FILE) + > + mem_cgroup_read_stat(memcg, LRU_INACTIVE_FILE); > + if (mem_cgroup_can_swap(memcg)) > + ret += mem_cgroup_read_stat(memcg, LRU_ACTIVE_ANON) + > + mem_cgroup_read_stat(memcg, LRU_INACTIVE_ANON); > + break; > + case MEMCG_NR_RECLAIM_PAGES: > + ret = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_FILE_DIRTY) + > + mem_cgroup_read_stat(memcg, > + MEM_CGROUP_STAT_UNSTABLE_NFS); > + break; > + case MEMCG_NR_WRITEBACK: > + ret = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_WRITEBACK); > + break; > + case MEMCG_NR_DIRTY_WRITEBACK_PAGES: > + ret = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_WRITEBACK) + > + mem_cgroup_read_stat(memcg, > + MEM_CGROUP_STAT_UNSTABLE_NFS); > + break; > + default: > + ret = 0; > + WARN_ON_ONCE(1); > + } > + return ret; > +} > + > +static int mem_cgroup_page_stat_cb(struct mem_cgroup *mem, void *data) > +{ > + struct mem_cgroup_page_stat *stat = (struct mem_cgroup_page_stat *)data; > + > + stat->value += mem_cgroup_get_local_page_stat(mem, stat->item); > + return 0; > +} > + > +s64 mem_cgroup_page_stat(enum mem_cgroup_page_stat_item item) > +{ > + struct mem_cgroup_page_stat stat = {}; > + struct mem_cgroup *memcg; > + > + if (mem_cgroup_disabled()) > + return -ENOMEM; > + rcu_read_lock(); > + memcg = mem_cgroup_from_task(current); > + if (memcg) { > + /* > + * Recursively evaulate page statistics against all cgroup > + * under hierarchy tree > + */ > + stat.item = item; > + mem_cgroup_walk_tree(memcg, &stat, mem_cgroup_page_stat_cb); > + } else > + stat.value = -ENOMEM; > + rcu_read_unlock(); > + > + return stat.value; > +} > + > static int mem_cgroup_count_children_cb(struct mem_cgroup *mem, void *data) > { > int *val = data; > @@ -1263,14 +1418,16 @@ static void record_last_oom(struct mem_cgroup *mem) > } > > /* > - * Currently used to update mapped file statistics, but the routine can be > - * generalized to update other statistics as well. > + * Generalized routine to update memory cgroup statistics. > */ > -void mem_cgroup_update_file_mapped(struct page *page, int val) > +void mem_cgroup_update_stat(struct page *page, > + enum mem_cgroup_stat_index idx, int val) > { > struct mem_cgroup *mem; > struct page_cgroup *pc; > > + if (mem_cgroup_disabled()) > + return; > pc = lookup_page_cgroup(page); > if (unlikely(!pc)) > return; > @@ -1286,7 +1443,8 @@ void mem_cgroup_update_file_mapped(struct page *page, int val) > /* > * Preemption is already disabled. We can use __this_cpu_xxx > */ > - __this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_FILE_MAPPED], val); > + VM_BUG_ON(idx >= MEM_CGROUP_STAT_NSTATS); > + __this_cpu_add(mem->stat->count[idx], val); > > done: > unlock_page_cgroup(pc); > @@ -3033,6 +3191,10 @@ enum { > MCS_PGPGIN, > MCS_PGPGOUT, > MCS_SWAP, > + MCS_FILE_DIRTY, > + MCS_WRITEBACK, > + MCS_WRITEBACK_TEMP, > + MCS_UNSTABLE_NFS, > MCS_INACTIVE_ANON, > MCS_ACTIVE_ANON, > MCS_INACTIVE_FILE, > @@ -3055,6 +3217,10 @@ struct { > {"pgpgin", "total_pgpgin"}, > {"pgpgout", "total_pgpgout"}, > {"swap", "total_swap"}, > + {"filedirty", "dirty_pages"}, > + {"writeback", "writeback_pages"}, > + {"writeback_tmp", "writeback_temp_pages"}, > + {"nfs", "nfs_unstable"}, > {"inactive_anon", "total_inactive_anon"}, > {"active_anon", "total_active_anon"}, > {"inactive_file", "total_inactive_file"}, > @@ -3083,6 +3249,14 @@ static int mem_cgroup_get_local_stat(struct mem_cgroup *mem, void *data) > val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_SWAPOUT); > s->stat[MCS_SWAP] += val * PAGE_SIZE; > } > + val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_FILE_DIRTY); > + s->stat[MCS_FILE_DIRTY] += val; > + val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_WRITEBACK); > + s->stat[MCS_WRITEBACK] += val; > + val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_WRITEBACK_TEMP); > + s->stat[MCS_WRITEBACK_TEMP] += val; > + val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_UNSTABLE_NFS); > + s->stat[MCS_UNSTABLE_NFS] += val; > > /* per zone stat */ > val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_ANON); > @@ -3467,6 +3641,50 @@ unlock: > return ret; > } > > +static u64 mem_cgroup_dirty_read(struct cgroup *cgrp, struct cftype *cft) > +{ > + struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); > + int type = cft->private; > + > + return get_dirty_param(memcg, type); > +} > + > +static int > +mem_cgroup_dirty_write(struct cgroup *cgrp, struct cftype *cft, u64 val) > +{ > + struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp); > + int type = cft->private; > + > + if (cgrp->parent == NULL) > + return -EINVAL; > + if (((type == MEM_CGROUP_DIRTY_RATIO) || > + (type == MEM_CGROUP_DIRTY_BACKGROUND_RATIO)) && (val > 100)) > + return -EINVAL; > + > + spin_lock(&memcg->reclaim_param_lock); > + switch (type) { > + case MEM_CGROUP_DIRTY_RATIO: > + memcg->dirty_param[MEM_CGROUP_DIRTY_RATIO] = val; > + memcg->dirty_param[MEM_CGROUP_DIRTY_BYTES] = 0; > + break; > + case MEM_CGROUP_DIRTY_BYTES: > + memcg->dirty_param[MEM_CGROUP_DIRTY_RATIO] = 0; > + memcg->dirty_param[MEM_CGROUP_DIRTY_BYTES] = val; > + break; > + case MEM_CGROUP_DIRTY_BACKGROUND_RATIO: > + memcg->dirty_param[MEM_CGROUP_DIRTY_BACKGROUND_RATIO] = val; > + memcg->dirty_param[MEM_CGROUP_DIRTY_BACKGROUND_BYTES] = 0; > + break; > + case MEM_CGROUP_DIRTY_BACKGROUND_BYTES: > + memcg->dirty_param[MEM_CGROUP_DIRTY_BACKGROUND_RATIO] = 0; > + memcg->dirty_param[MEM_CGROUP_DIRTY_BACKGROUND_BYTES] = val; > + break; > + } > + spin_unlock(&memcg->reclaim_param_lock); > + > + return 0; > +} > + > static struct cftype mem_cgroup_files[] = { > { > .name = "usage_in_bytes", > @@ -3518,6 +3736,30 @@ static struct cftype mem_cgroup_files[] = { > .write_u64 = mem_cgroup_swappiness_write, > }, > { > + .name = "dirty_ratio", > + .read_u64 = mem_cgroup_dirty_read, > + .write_u64 = mem_cgroup_dirty_write, > + .private = MEM_CGROUP_DIRTY_RATIO, > + }, > + { > + .name = "dirty_bytes", > + .read_u64 = mem_cgroup_dirty_read, > + .write_u64 = mem_cgroup_dirty_write, > + .private = MEM_CGROUP_DIRTY_BYTES, > + }, > + { > + .name = "dirty_background_ratio", > + .read_u64 = mem_cgroup_dirty_read, > + .write_u64 = mem_cgroup_dirty_write, > + .private = MEM_CGROUP_DIRTY_BACKGROUND_RATIO, > + }, > + { > + .name = "dirty_background_bytes", > + .read_u64 = mem_cgroup_dirty_read, > + .write_u64 = mem_cgroup_dirty_write, > + .private = MEM_CGROUP_DIRTY_BACKGROUND_BYTES, > + }, > + { > .name = "move_charge_at_immigrate", > .read_u64 = mem_cgroup_move_charge_read, > .write_u64 = mem_cgroup_move_charge_write, > @@ -3725,6 +3967,19 @@ static int mem_cgroup_soft_limit_tree_init(void) > return 0; > } > > +/* > + * NOTE: called only with &src->reclaim_param_lock held from > + * mem_cgroup_create(). > + */ > +static inline void > +copy_dirty_params(struct mem_cgroup *dst, struct mem_cgroup *src) > +{ > + int i; > + > + for (i = 0; i < MEM_CGROUP_DIRTY_NPARAMS; i++) > + dst->dirty_param[i] = src->dirty_param[i]; > +} > + > static struct cgroup_subsys_state * __ref > mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) > { > @@ -3776,8 +4031,37 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) > mem->last_scanned_child = 0; > spin_lock_init(&mem->reclaim_param_lock); > > - if (parent) > + if (parent) { > mem->swappiness = get_swappiness(parent); > + > + spin_lock(&parent->reclaim_param_lock); > + copy_dirty_params(mem, parent); > + spin_unlock(&parent->reclaim_param_lock); > + } else { > + /* > + * XXX: should we need a lock here? we could switch from > + * vm_dirty_ratio to vm_dirty_bytes or vice versa but we're not > + * reading them atomically. The same for dirty_background_ratio > + * and dirty_background_bytes. > + * > + * For now, try to read them speculatively and retry if a > + * "conflict" is detected.a The do while loop is subtle, can we add a validate check,share it with the write routine and retry if validation fails? > + */ > + do { > + mem->dirty_param[MEM_CGROUP_DIRTY_RATIO] = > + vm_dirty_ratio; > + mem->dirty_param[MEM_CGROUP_DIRTY_BYTES] = > + vm_dirty_bytes; > + } while (mem->dirty_param[MEM_CGROUP_DIRTY_RATIO] && > + mem->dirty_param[MEM_CGROUP_DIRTY_BYTES]); > + do { > + mem->dirty_param[MEM_CGROUP_DIRTY_BACKGROUND_RATIO] = > + dirty_background_ratio; > + mem->dirty_param[MEM_CGROUP_DIRTY_BACKGROUND_BYTES] = > + dirty_background_bytes; > + } while (mem->dirty_param[MEM_CGROUP_DIRTY_BACKGROUND_RATIO] && > + mem->dirty_param[MEM_CGROUP_DIRTY_BACKGROUND_BYTES]); > + } > atomic_set(&mem->refcnt, 1); > mem->move_charge_at_immigrate = 0; > mutex_init(&mem->thresholds_lock); > -- > 1.6.3.3 > -- Three Cheers, Balbir -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . 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