[Devel] Re: [PATCH -mmotm 2/3] memcg: dirty pages accounting and limiting infrastructure
Greg Thelen
gthelen at google.com
Tue Mar 2 10:09:46 PST 2010
Comments below. Yet to be tested on my end, but I will test it.
On Mon, Mar 1, 2010 at 1:23 PM, 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 | 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);
> +
> 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);
> +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];
> +
> /* 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);
> +
> + 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;
> +}
Given that mem_cgroup_dirty_[background_]{ratio,bytes}() are similar,
should we refactor the majority of them into a single routine?
--
Greg
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