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>
---
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;
+}
+
+static inline bool mem_cgroup_can_swap(struct mem_cgroup *memcg)
+{
+ return do_swap_account ?
+ res_counter_read_u64(&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.
+ */
+ 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
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