[PATCH -mmotm 4/5] memcg: dirty pages accounting and limiting infrastructure

Daisuke Nishimura nishimura at mxp.nes.nec.co.jp
Mon Mar 15 19:32:38 PDT 2010


On Mon, 15 Mar 2010 00:26:41 +0100, Andrea Righi <arighi at develer.com> wrote:
> 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 at develer.com>
> ---
>  include/linux/memcontrol.h |   92 ++++++++-
>  mm/memcontrol.c            |  484 +++++++++++++++++++++++++++++++++++++++++---
>  2 files changed, 540 insertions(+), 36 deletions(-)
> 
> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
> index 88d3f9e..0602ec9 100644
> --- a/include/linux/memcontrol.h
> +++ b/include/linux/memcontrol.h
> @@ -19,12 +19,55 @@
>  
>  #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_read_page_stat_item {
> +	MEMCG_NR_DIRTYABLE_PAGES,
> +	MEMCG_NR_RECLAIM_PAGES,
> +	MEMCG_NR_WRITEBACK,
> +	MEMCG_NR_DIRTY_WRITEBACK_PAGES,
> +};
> +
> +/* File cache pages accounting */
> +enum mem_cgroup_write_page_stat_item {
> +	MEMCG_NR_FILE_MAPPED,		/* # of pages charged as file rss */
> +	MEMCG_NR_FILE_DIRTY,		/* # of dirty pages in page cache */
> +	MEMCG_NR_FILE_WRITEBACK,	/* # of pages under writeback */
> +	MEMCG_NR_FILE_WRITEBACK_TEMP,	/* # of pages under writeback using
> +					   temporary buffers */
> +	MEMCG_NR_FILE_UNSTABLE_NFS,	/* # of NFS unstable pages */
> +
> +	MEMCG_NR_FILE_NSTAT,
> +};
> +
> +/* Dirty memory parameters */
> +struct vm_dirty_param {
> +	int dirty_ratio;
> +	int dirty_background_ratio;
> +	unsigned long dirty_bytes;
> +	unsigned long dirty_background_bytes;
> +};
> +
> +/*
> + * TODO: provide a validation check routine. And retry if validation
> + * fails.
> + */
> +static inline void get_global_vm_dirty_param(struct vm_dirty_param *param)
> +{
> +	param->dirty_ratio = vm_dirty_ratio;
> +	param->dirty_bytes = vm_dirty_bytes;
> +	param->dirty_background_ratio = dirty_background_ratio;
> +	param->dirty_background_bytes = dirty_background_bytes;
> +}
> +
>  #ifdef CONFIG_CGROUP_MEM_RES_CTLR
>  /*
>   * All "charge" functions with gfp_mask should use GFP_KERNEL or
> @@ -117,6 +160,25 @@ extern void mem_cgroup_print_oom_info(struct mem_cgroup *memcg,
>  extern int do_swap_account;
>  #endif
>  
> +extern bool mem_cgroup_has_dirty_limit(void);
> +extern void get_vm_dirty_param(struct vm_dirty_param *param);
> +extern s64 mem_cgroup_page_stat(enum mem_cgroup_read_page_stat_item item);
> +
> +extern void mem_cgroup_update_page_stat(struct page *page,
> +			enum mem_cgroup_write_page_stat_item idx, bool charge);
> +
> +static inline void mem_cgroup_inc_page_stat(struct page *page,
> +		enum mem_cgroup_write_page_stat_item idx)
> +{
> +	mem_cgroup_update_page_stat(page, idx, true);
> +}
> +
> +static inline void mem_cgroup_dec_page_stat(struct page *page,
> +		enum mem_cgroup_write_page_stat_item idx)
> +{
> +	mem_cgroup_update_page_stat(page, idx, false);
> +}
> +
>  static inline bool mem_cgroup_disabled(void)
>  {
>  	if (mem_cgroup_subsys.disabled)
> @@ -124,12 +186,6 @@ static inline bool mem_cgroup_disabled(void)
>  	return false;
>  }
>  
> -enum mem_cgroup_page_stat_item {
> -	MEMCG_NR_FILE_MAPPED,
> -	MEMCG_NR_FILE_NSTAT,
> -};
> -
> -void mem_cgroup_update_stat(struct page *page, int idx, bool charge);
>  unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
>  						gfp_t gfp_mask, int nid,
>  						int zid);
> @@ -299,8 +355,18 @@ 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 s64 mem_cgroup_page_stat(enum mem_cgroup_read_page_stat_item item)
> +{
> +	return -ENOSYS;
> +}
> +
> +static inline void mem_cgroup_inc_page_stat(struct page *page,
> +			enum mem_cgroup_write_page_stat_item idx)
> +{
> +}
> +
> +static inline void mem_cgroup_dec_page_stat(struct page *page,
> +			enum mem_cgroup_write_page_stat_item idx)
>  {
>  }
>  
> @@ -311,6 +377,16 @@ unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
>  	return 0;
>  }
>  
> +static inline bool mem_cgroup_has_dirty_limit(void)
> +{
> +	return false;
> +}
> +
> +static inline void get_vm_dirty_param(struct vm_dirty_param *param)
> +{
> +	get_global_vm_dirty_param(param);
> +}
> +
>  #endif /* CONFIG_CGROUP_MEM_CONT */
>  
>  #endif /* _LINUX_MEMCONTROL_H */
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index b7c23ea..91770d0 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -80,14 +80,21 @@ 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_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_EVENTS,	/* incremented at every  pagein/pageout */
>  
> +	/* File cache pages accounting */
> +	MEM_CGROUP_STAT_FILE_MAPPED,  /* # of pages charged as file rss */
> +	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,
>  };
>  
> @@ -95,6 +102,19 @@ struct mem_cgroup_stat_cpu {
>  	s64 count[MEM_CGROUP_STAT_NSTATS];
>  };
>  
> +/* Per cgroup page statistics */
> +struct mem_cgroup_page_stat {
> +	enum mem_cgroup_read_page_stat_item item;
> +	s64 value;
> +};
> +
> +enum {
> +	MEM_CGROUP_DIRTY_RATIO,
> +	MEM_CGROUP_DIRTY_BYTES,
> +	MEM_CGROUP_DIRTY_BACKGROUND_RATIO,
> +	MEM_CGROUP_DIRTY_BACKGROUND_BYTES,
> +};
> +
>  /*
>   * per-zone information in memory controller.
>   */
> @@ -208,6 +228,9 @@ struct mem_cgroup {
>  
>  	unsigned int	swappiness;
>  
> +	/* control memory cgroup dirty pages */
> +	struct vm_dirty_param dirty_param;
> +
>  	/* set when res.limit == memsw.limit */
>  	bool		memsw_is_minimum;
>  
> @@ -1033,6 +1056,189 @@ static unsigned int get_swappiness(struct mem_cgroup *memcg)
>  	return swappiness;
>  }
>  
> +static bool dirty_param_is_valid(struct vm_dirty_param *param)
> +{
> +	if (param->dirty_ratio && param->dirty_bytes)
> +		return false;
> +	if (param->dirty_background_ratio && param->dirty_background_bytes)
> +		return false;
> +	return true;
> +}
> +
> +static void __mem_cgroup_get_dirty_param(struct vm_dirty_param *param,
> +				struct mem_cgroup *mem)
> +{
> +	param->dirty_ratio = mem->dirty_param.dirty_ratio;
> +	param->dirty_bytes = mem->dirty_param.dirty_bytes;
> +	param->dirty_background_ratio = mem->dirty_param.dirty_background_ratio;
> +	param->dirty_background_bytes = mem->dirty_param.dirty_background_bytes;
> +}
> +
> +/*
> + * get_vm_dirty_param() - get dirty memory parameters of the current memcg
> + * @param:	a structure that is filled with the dirty memory settings
> + *
> + * The function fills @param with the current memcg dirty memory settings. If
> + * memory cgroup is disabled or in case of error the structure is filled with
> + * the global dirty memory settings.
> + */
> +void get_vm_dirty_param(struct vm_dirty_param *param)
> +{
> +	struct mem_cgroup *memcg;
> +
> +	if (mem_cgroup_disabled()) {
> +		get_global_vm_dirty_param(param);
> +		return;
> +	}
> +	/*
> +	 * 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().
> +	 */
> +	while (1) {
> +		rcu_read_lock();
> +		memcg = mem_cgroup_from_task(current);
> +		if (likely(memcg))
> +			__mem_cgroup_get_dirty_param(param, memcg);
> +		else
> +			get_global_vm_dirty_param(param);
> +		rcu_read_unlock();
> +		/*
> +		 * Since global and memcg vm_dirty_param are not protected we
> +		 * try to speculatively read them and retry if we get
> +		 * inconsistent values.
> +		 */
> +		if (likely(dirty_param_is_valid(param)))
> +			break;
> +	}
> +}
> +
> +/*
> + * mem_cgroup_has_dirty_limit() - check if current memcg has local dirty limits
> + *
> + * Return true if the current memory cgroup has local dirty memory settings,
> + * false otherwise.
> + */
> +bool mem_cgroup_has_dirty_limit(void)
> +{
> +	struct mem_cgroup *mem;
> +
> +	if (mem_cgroup_disabled())
> +		return false;
> +	mem = mem_cgroup_from_task(current);
> +	return mem && !mem_cgroup_is_root(mem);
> +}
> +
> +static inline bool mem_cgroup_can_swap(struct mem_cgroup *memcg)
> +{
> +	if (!do_swap_account)
> +		return nr_swap_pages > 0;
> +	return !memcg->memsw_is_minimum &&
> +		(res_counter_read_u64(&memcg->memsw, RES_LIMIT) > 0);
> +}
> +
> +static s64 mem_cgroup_get_local_page_stat(struct mem_cgroup *memcg,
> +				enum mem_cgroup_read_page_stat_item item)
> +{
> +	s64 ret;
> +
> +	switch (item) {
> +	case MEMCG_NR_DIRTYABLE_PAGES:
> +		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:
> +		BUG();
> +		break;
> +	}
> +	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;
> +}
> +
> +static unsigned long long
> +memcg_get_hierarchical_free_pages(struct mem_cgroup *mem)
> +{
> +	struct cgroup *cgroup;
> +	unsigned long long min_free, free;
> +
> +	min_free = res_counter_read_u64(&mem->res, RES_LIMIT) -
> +			res_counter_read_u64(&mem->res, RES_USAGE);
> +	cgroup = mem->css.cgroup;
> +	if (!mem->use_hierarchy)
> +		goto out;
> +
> +	while (cgroup->parent) {
> +		cgroup = cgroup->parent;
> +		mem = mem_cgroup_from_cont(cgroup);
> +		if (!mem->use_hierarchy)
> +			break;
> +		free = res_counter_read_u64(&mem->res, RES_LIMIT) -
> +			res_counter_read_u64(&mem->res, RES_USAGE);
> +		min_free = min(min_free, free);
> +	}
> +out:
> +	/* Translate free memory in pages */
> +	return min_free >> PAGE_SHIFT;
> +}
> +
> +/*
> + * mem_cgroup_page_stat() - get memory cgroup file cache statistics
> + * @item:	memory statistic item exported to the kernel
> + *
> + * Return the accounted statistic value, or a negative value in case of error.
> + */
> +s64 mem_cgroup_page_stat(enum mem_cgroup_read_page_stat_item item)
> +{
> +	struct mem_cgroup_page_stat stat = {};
> +	struct mem_cgroup *mem;
> +
> +	rcu_read_lock();
> +	mem = mem_cgroup_from_task(current);
> +	if (mem && !mem_cgroup_is_root(mem)) {
> +		/*
> +		 * If we're looking for dirtyable pages we need to evaluate
> +		 * free pages depending on the limit and usage of the parents
> +		 * first of all.
> +		 */
> +		if (item == MEMCG_NR_DIRTYABLE_PAGES)
> +			stat.value = memcg_get_hierarchical_free_pages(mem);
> +		/*
> +		 * Recursively evaluate page statistics against all cgroup
> +		 * under hierarchy tree
> +		 */
> +		stat.item = item;
> +		mem_cgroup_walk_tree(mem, &stat, mem_cgroup_page_stat_cb);
> +	} else
> +		stat.value = -EINVAL;
> +	rcu_read_unlock();
> +
> +	return stat.value;
> +}
> +
hmm, mem_cgroup_page_stat() can return negative value, but you place BUG_ON()
in [5/5] to check it returns negative value. What happens if the current is moved
to root between mem_cgroup_has_dirty_limit() and mem_cgroup_page_stat() ?
How about making mem_cgroup_has_dirty_limit() return the target mem_cgroup, and
passing the mem_cgroup to mem_cgroup_page_stat() ?

>  static int mem_cgroup_count_children_cb(struct mem_cgroup *mem, void *data)
>  {
>  	int *val = data;
> @@ -1344,24 +1550,16 @@ bool mem_cgroup_handle_oom(struct mem_cgroup *mem, gfp_t mask)
>  	return true;
>  }
>  
> -/*
> - * Currently used to update mapped file statistics, but the routine can be
> - * generalized to update other statistics as well.
> - */
> -void __mem_cgroup_update_stat(struct page_cgroup *pc, int idx, bool charge)
> +static void __mem_cgroup_update_page_stat(struct page_cgroup *pc,
> +				int idx, bool charge)
>  {
>  	struct mem_cgroup *mem;
> -	int val;
> +	int val = charge ? 1 : -1;
>  
>  	mem = pc->mem_cgroup;
>  	if (!mem || !PageCgroupUsed(pc))
>  		return;
>  
> -	if (charge)
> -		val = 1;
> -	else
> -		val = -1;
> -
>  	switch (idx) {
>  	case MEMCG_NR_FILE_MAPPED:
>  		if (charge) {
> @@ -1377,6 +1575,62 @@ void __mem_cgroup_update_stat(struct page_cgroup *pc, int idx, bool charge)
>  		}
>  		idx = MEM_CGROUP_STAT_FILE_MAPPED;
>  		break;
> +	case MEMCG_NR_FILE_DIRTY:
> +		if (charge) {
> +			if (!PageCgroupFileDirty(pc))
> +				SetPageCgroupFileDirty(pc);
> +			else
> +				val = 0;
> +		} else {
> +			if (PageCgroupFileDirty(pc))
> +				ClearPageCgroupFileDirty(pc);
> +			else
> +				val = 0;
> +		}
> +		idx = MEM_CGROUP_STAT_FILE_DIRTY;
> +		break;
> +	case MEMCG_NR_FILE_WRITEBACK:
> +		if (charge) {
> +			if (!PageCgroupFileWriteback(pc))
> +				SetPageCgroupFileWriteback(pc);
> +			else
> +				val = 0;
> +		} else {
> +			if (PageCgroupFileWriteback(pc))
> +				ClearPageCgroupFileWriteback(pc);
> +			else
> +				val = 0;
> +		}
> +		idx = MEM_CGROUP_STAT_WRITEBACK;
> +		break;
> +	case MEMCG_NR_FILE_WRITEBACK_TEMP:
> +		if (charge) {
> +			if (!PageCgroupFileWritebackTemp(pc))
> +				SetPageCgroupFileWritebackTemp(pc);
> +			else
> +				val = 0;
> +		} else {
> +			if (PageCgroupFileWritebackTemp(pc))
> +				ClearPageCgroupFileWritebackTemp(pc);
> +			else
> +				val = 0;
> +		}
> +		idx = MEM_CGROUP_STAT_WRITEBACK_TEMP;
> +		break;
> +	case MEMCG_NR_FILE_UNSTABLE_NFS:
> +		if (charge) {
> +			if (!PageCgroupFileUnstableNFS(pc))
> +				SetPageCgroupFileUnstableNFS(pc);
> +			else
> +				val = 0;
> +		} else {
> +			if (PageCgroupFileUnstableNFS(pc))
> +				ClearPageCgroupFileUnstableNFS(pc);
> +			else
> +				val = 0;
> +		}
> +		idx = MEM_CGROUP_STAT_UNSTABLE_NFS;
> +		break;
>  	default:
>  		BUG();
>  		break;
> @@ -1384,34 +1638,81 @@ void __mem_cgroup_update_stat(struct page_cgroup *pc, int idx, bool charge)
>  	/*
>  	 * Preemption is already disabled. We can use __this_cpu_xxx
>  	 */
> -	__this_cpu_add(mem->stat->count[idx], val);
> +	if (val)
> +		__this_cpu_add(mem->stat->count[idx], val);
>  }
>  
> -void mem_cgroup_update_stat(struct page *page, int idx, bool charge)
> +/*
> + * mem_cgroup_update_page_stat() - update memcg file cache's accounting
> + * @page:	the page involved in a file cache operation.
> + * @idx:	the particular file cache statistic.
> + * @charge:	true to increment, false to decrement the statistic specified
> + *		by @idx.
> + *
> + * Update memory cgroup file cache's accounting.
> + */
> +void mem_cgroup_update_page_stat(struct page *page,
> +			enum mem_cgroup_write_page_stat_item idx, bool charge)
>  {
>  	struct page_cgroup *pc;
>  
> +	if (mem_cgroup_disabled())
> +		return;
>  	pc = lookup_page_cgroup(page);
>  	if (!pc || mem_cgroup_is_root(pc->mem_cgroup))
>  		return;
>  
>  	if (trylock_page_cgroup(pc)) {
> -		__mem_cgroup_update_stat(pc, idx, charge);
> +		__mem_cgroup_update_page_stat(pc, idx, charge);
>  		unlock_page_cgroup(pc);
>  	}
> -	return;
>  }
> +EXPORT_SYMBOL_GPL(mem_cgroup_update_page_stat);
>  
> -static void mem_cgroup_migrate_stat(struct page_cgroup *pc,
> +/* Update file cache accounted statistics on task migration. */
> +static void mem_cgroup_migrate_file_stat(struct page_cgroup *pc,
>  	struct mem_cgroup *from, struct mem_cgroup *to)
>  {
>  	if (PageCgroupFileMapped(pc)) {
>  		__this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
> -		if (!mem_cgroup_is_root(to)) {
> -			__this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
> -		} else {
> +		if (!mem_cgroup_is_root(to))
> +			__this_cpu_inc(
> +				to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
> +		else
>  			ClearPageCgroupFileMapped(pc);
> -		}
> +	}
> +	if (PageCgroupFileDirty(pc)) {
> +		__this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_DIRTY]);
> +		if (!mem_cgroup_is_root(to))
> +			__this_cpu_inc(
> +				to->stat->count[MEM_CGROUP_STAT_FILE_DIRTY]);
> +		else
> +			ClearPageCgroupFileDirty(pc);
> +	}
> +	if (PageCgroupFileWriteback(pc)) {
> +		__this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_WRITEBACK]);
> +		if (!mem_cgroup_is_root(to))
> +			__this_cpu_inc(
> +				to->stat->count[MEM_CGROUP_STAT_WRITEBACK]);
> +		else
> +			ClearPageCgroupFileWriteback(pc);
> +	}
> +	if (PageCgroupFileWritebackTemp(pc)) {
> +		__this_cpu_dec(
> +			from->stat->count[MEM_CGROUP_STAT_WRITEBACK_TEMP]);
> +		if (!mem_cgroup_is_root(to))
> +			__this_cpu_inc(to->stat->count[
> +					MEM_CGROUP_STAT_WRITEBACK_TEMP]);
> +		else
> +			ClearPageCgroupFileWritebackTemp(pc);
> +	}
> +	if (PageCgroupFileUnstableNFS(pc)) {
> +		__this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_UNSTABLE_NFS]);
> +		if (!mem_cgroup_is_root(to))
> +			__this_cpu_inc(
> +				to->stat->count[MEM_CGROUP_STAT_UNSTABLE_NFS]);
> +		else
> +			ClearPageCgroupFileUnstableNFS(pc);
>  	}
>  }
>  
> @@ -1425,6 +1726,23 @@ __mem_cgroup_stat_fixup(struct page_cgroup *pc, struct mem_cgroup *mem)
>  		__this_cpu_dec(mem->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
>  		ClearPageCgroupFileMapped(pc);
>  	}
> +	if (PageCgroupFileDirty(pc)) {
> +		__this_cpu_dec(mem->stat->count[MEM_CGROUP_STAT_FILE_DIRTY]);
> +		ClearPageCgroupFileDirty(pc);
> +	}
> +	if (PageCgroupFileWriteback(pc)) {
> +		__this_cpu_dec(mem->stat->count[MEM_CGROUP_STAT_WRITEBACK]);
> +		ClearPageCgroupFileWriteback(pc);
> +	}
> +	if (PageCgroupFileWritebackTemp(pc)) {
> +		__this_cpu_dec(
> +			mem->stat->count[MEM_CGROUP_STAT_WRITEBACK_TEMP]);
> +		ClearPageCgroupFileWritebackTemp(pc);
> +	}
> +	if (PageCgroupFileUnstableNFS(pc)) {
> +		__this_cpu_dec(mem->stat->count[MEM_CGROUP_STAT_UNSTABLE_NFS]);
> +		ClearPageCgroupFileUnstableNFS(pc);
> +	}
>  }
>  
>  /*
> @@ -1863,7 +2181,7 @@ static void __mem_cgroup_move_account(struct page_cgroup *pc,
>  	VM_BUG_ON(pc->mem_cgroup != from);
>  
>  	page = pc->page;
> -	mem_cgroup_migrate_stat(pc, from, to);
> +	mem_cgroup_migrate_file_stat(pc, from, to);
>  	mem_cgroup_charge_statistics(from, pc, false);
>  	if (uncharge)
>  		/* This is not "cancel", but cancel_charge does all we need. */
> @@ -3168,10 +3486,14 @@ static int mem_cgroup_move_charge_write(struct cgroup *cgrp,
>  enum {
>  	MCS_CACHE,
>  	MCS_RSS,
> -	MCS_FILE_MAPPED,
>  	MCS_PGPGIN,
>  	MCS_PGPGOUT,
>  	MCS_SWAP,
> +	MCS_FILE_MAPPED,
> +	MCS_FILE_DIRTY,
> +	MCS_WRITEBACK,
> +	MCS_WRITEBACK_TEMP,
> +	MCS_UNSTABLE_NFS,
>  	MCS_INACTIVE_ANON,
>  	MCS_ACTIVE_ANON,
>  	MCS_INACTIVE_FILE,
> @@ -3190,10 +3512,14 @@ struct {
>  } memcg_stat_strings[NR_MCS_STAT] = {
>  	{"cache", "total_cache"},
>  	{"rss", "total_rss"},
> -	{"mapped_file", "total_mapped_file"},
>  	{"pgpgin", "total_pgpgin"},
>  	{"pgpgout", "total_pgpgout"},
>  	{"swap", "total_swap"},
> +	{"mapped_file", "total_mapped_file"},
> +	{"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"},
Why not using "total_xxx" for total_name ?

> @@ -3212,8 +3538,6 @@ static int mem_cgroup_get_local_stat(struct mem_cgroup *mem, void *data)
>  	s->stat[MCS_CACHE] += val * PAGE_SIZE;
>  	val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS);
>  	s->stat[MCS_RSS] += val * PAGE_SIZE;
> -	val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_FILE_MAPPED);
> -	s->stat[MCS_FILE_MAPPED] += val * PAGE_SIZE;
>  	val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_PGPGIN_COUNT);
>  	s->stat[MCS_PGPGIN] += val;
>  	val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_PGPGOUT_COUNT);
> @@ -3222,6 +3546,16 @@ 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_MAPPED);
> +	s->stat[MCS_FILE_MAPPED] += 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;
>  
I don't have a strong objection, but I prefer showing them in bytes.
And can you add to mem_cgroup_stat_show() something like:

	for (i = 0; i < NR_MCS_STAT; i++) {
		if (i == MCS_SWAP && !do_swap_account)
			continue;
+		if (i >= MCS_FILE_STAT_STAR && i <= MCS_FILE_STAT_END &&
+		   mem_cgroup_is_root(mem_cont))
+			continue;
		cb->fill(cb, memcg_stat_strings[i].local_name, mystat.stat[i]);
	}

not to show file stat in root cgroup ? It's meaningless value anyway.
Of course, you'd better mention it in [2/5] too.


Thanks,
Daisuke Nishimura.

>  	/* per zone stat */
>  	val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_ANON);
> @@ -3583,6 +3917,63 @@ unlock:
>  	return ret;
>  }
>  
> +static u64 mem_cgroup_dirty_read(struct cgroup *cgrp, struct cftype *cft)
> +{
> +	struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
> +
> +	switch (cft->private) {
> +	case MEM_CGROUP_DIRTY_RATIO:
> +		return memcg->dirty_param.dirty_ratio;
> +	case MEM_CGROUP_DIRTY_BYTES:
> +		return memcg->dirty_param.dirty_bytes;
> +	case MEM_CGROUP_DIRTY_BACKGROUND_RATIO:
> +		return memcg->dirty_param.dirty_background_ratio;
> +	case MEM_CGROUP_DIRTY_BACKGROUND_BYTES:
> +		return memcg->dirty_param.dirty_background_bytes;
> +	default:
> +		BUG();
> +	}
> +}
> +
> +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;
> +	/*
> +	 * TODO: provide a validation check routine. And retry if validation
> +	 * fails.
> +	 */
> +	switch (type) {
> +	case MEM_CGROUP_DIRTY_RATIO:
> +		memcg->dirty_param.dirty_ratio = val;
> +		memcg->dirty_param.dirty_bytes = 0;
> +		break;
> +	case MEM_CGROUP_DIRTY_BYTES:
> +		memcg->dirty_param.dirty_ratio  = 0;
> +		memcg->dirty_param.dirty_bytes = val;
> +		break;
> +	case MEM_CGROUP_DIRTY_BACKGROUND_RATIO:
> +		memcg->dirty_param.dirty_background_ratio = val;
> +		memcg->dirty_param.dirty_background_bytes = 0;
> +		break;
> +	case MEM_CGROUP_DIRTY_BACKGROUND_BYTES:
> +		memcg->dirty_param.dirty_background_ratio = 0;
> +		memcg->dirty_param.dirty_background_bytes = val;
> +		break;
> +	default:
> +		BUG();
> +		break;
> +	}
> +	return 0;
> +}
> +
>  static struct cftype mem_cgroup_files[] = {
>  	{
>  		.name = "usage_in_bytes",
> @@ -3634,6 +4025,30 @@ 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,
> @@ -3892,8 +4307,21 @@ 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);
> +		mem->dirty_param = parent->dirty_param;
> +	} else {
> +		while (1) {
> +			get_global_vm_dirty_param(&mem->dirty_param);
> +			/*
> +			 * Since global dirty parameters are not protected we
> +			 * try to speculatively read them and retry if we get
> +			 * inconsistent values.
> +			 */
> +			if (likely(dirty_param_is_valid(&mem->dirty_param)))
> +				break;
> +		}
> +	}
>  	atomic_set(&mem->refcnt, 1);
>  	mem->move_charge_at_immigrate = 0;
>  	mutex_init(&mem->thresholds_lock);
> -- 
> 1.6.3.3
> 


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