page-cache-cgroup-stats-linux-3.10.patch

diff --git a/block/blk-core.c b/block/blk-core.c
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1876,6 +1876,9 @@ void submit_bio(int rw, struct bio *bio)
 			count_vm_events(PGPGOUT, count);
 		} else {
 			task_io_account_read(bio->bi_size);
+#ifdef CONFIG_MEMCG_PAGECACHE_HIT
+			mem_cgroup_charge_pagecache_stat(MEM_CGROUP_SUBMIT_IO_READ, bio->bi_size);
+#endif
 			count_vm_events(PGPGIN, count);
 		}
 
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -35,6 +35,15 @@ enum mem_cgroup_page_stat_item {
 	MEMCG_NR_FILE_MAPPED, /* # of pages charged as file rss */
 };
 
+#ifdef CONFIG_MEMCG_PAGECACHE_HIT
+enum mem_cgroup_pagecache_stat_index{
+	MEM_CGROUP_PAGECACHE_READ,
+	MEM_CGROUP_READAHEAD_READ,
+	MEM_CGROUP_SUBMIT_IO_READ,
+	MEM_CGROUP_PAGECACHE_STAT_NSTATS,
+};
+#endif
+
 struct mem_cgroup_reclaim_cookie {
 	struct zone *zone;
 	int priority;
@@ -53,6 +62,11 @@ struct mem_cgroup_reclaim_cookie {
  * (Of course, if memcg does memory allocation in future, GFP_KERNEL is sane.)
  */
 
+#ifdef CONFIG_MEMCG_PAGECACHE_HIT
+void mem_cgroup_charge_pagecache_stat(enum mem_cgroup_pagecache_stat_index idx, 
+					ssize_t written);
+#endif
+
 extern int mem_cgroup_newpage_charge(struct page *page, struct mm_struct *mm,
 				gfp_t gfp_mask);
 /* for swap handling */
diff --git a/init/Kconfig b/init/Kconfig
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -967,6 +967,12 @@ config CGROUP_HUGETLB
 	  control group is tracked in the third page lru pointer. This means
 	  that we cannot use the controller with huge page less than 3 pages.
 
+config MEMCG_PAGECACHE_HIT
+	bool "PageCache Hit/Miss stats"
+	depends on MEMCG
+	help
+	  Provides statistic
+
 config CGROUP_PERF
 	bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
 	depends on PERF_EVENTS && CGROUPS
diff --git a/mm/filemap.c b/mm/filemap.c
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1515,6 +1515,9 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
 			break;
 	}
 out:
+#ifdef CONFIG_MEMCG_PAGECACHE_HIT
+	mem_cgroup_charge_pagecache_stat(MEM_CGROUP_PAGECACHE_READ, retval);
+#endif
 	return retval;
 }
 EXPORT_SYMBOL(generic_file_aio_read);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -108,6 +108,14 @@ static const char * const mem_cgroup_stat_names[] = {
 	"swap",
 };
 
+#ifdef CONFIG_MEMCG_PAGECACHE_HIT
+static const char * const mem_cgroup_pagecache_stat_names[] = {
+	"general_read",
+	"readahead_read",
+	"submit_bio_read",
+};
+#endif
+
 enum mem_cgroup_events_index {
 	MEM_CGROUP_EVENTS_PGPGIN,	/* # of pages paged in */
 	MEM_CGROUP_EVENTS_PGPGOUT,	/* # of pages paged out */
@@ -154,6 +162,12 @@ struct mem_cgroup_stat_cpu {
 	unsigned long targets[MEM_CGROUP_NTARGETS];
 };
 
+#ifdef CONFIG_MEMCG_PAGECACHE_HIT
+struct mem_cgroup_pagecache_stat_cpu {
+	u64 count[MEM_CGROUP_PAGECACHE_STAT_NSTATS];
+};
+#endif
+
 struct mem_cgroup_reclaim_iter {
 	/*
 	 * last scanned hierarchy member. Valid only if last_dead_count
@@ -370,6 +384,10 @@ struct mem_cgroup {
 	atomic_t	numainfo_updating;
 #endif
 
+#ifdef CONFIG_MEMCG_PAGECACHE_HIT
+	struct mem_cgroup_pagecache_stat_cpu __percpu *pagecache_stat;
+#endif
+
 	/*
 	 * Per cgroup active and inactive list, similar to the
 	 * per zone LRU lists.
@@ -899,6 +917,23 @@ static long mem_cgroup_read_stat(struct mem_cgroup *memcg,
 	return val;
 }
 
+#ifdef CONFIG_MEMCG_PAGECACHE_HIT
+static long mem_cgroup_read_pagecache_stat(struct mem_cgroup *memcg,
+				 enum mem_cgroup_pagecache_stat_index idx)
+{
+	long val = 0;
+	int cpu;
+
+	get_online_cpus();
+	for_each_online_cpu(cpu)
+		val += per_cpu(memcg->pagecache_stat->count[idx], cpu);
+
+// TODO drains percpu
+	put_online_cpus();
+	return val;
+}
+#endif
+
 static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg,
 					 bool charge)
 {
@@ -1107,6 +1142,23 @@ struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
 	return memcg;
 }
 
+#ifdef CONFIG_MEMCG_PAGECACHE_HIT
+void mem_cgroup_charge_pagecache_stat(enum mem_cgroup_pagecache_stat_index idx, 
+									  ssize_t written)
+{
+	struct mem_cgroup *memcg;
+
+	preempt_disable();
+	memcg = try_get_mem_cgroup_from_mm(current->mm);
+	if (unlikely(!memcg))
+		memcg = root_mem_cgroup;
+
+	__this_cpu_add(memcg->pagecache_stat->count[idx], written);
+	preempt_enable();
+}
+EXPORT_SYMBOL(mem_cgroup_charge_pagecache_stat);
+#endif
+
 /*
  * Returns a next (in a pre-order walk) alive memcg (with elevated css
  * ref. count) or NULL if the whole root's subtree has been visited.
@@ -5401,6 +5453,28 @@ static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
 	return 0;
 }
 
+#ifdef CONFIG_MEMCG_PAGECACHE_HIT
+//static ssize_t mem_cgroup_pagecache_stat_reset(struct kernfs_open_file *of, char *buf,
+//							size_t nbytes, loff_t off)
+static int mem_cgroup_pagecache_stat_reset(struct cgroup *cont, unsigned int event)
+{
+	int i;
+	int cpu;
+	struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
+
+	get_online_cpus();
+	for_each_online_cpu(cpu) {
+		spin_lock(&memcg->pcp_counter_lock);
+		for (i = 0; i < MEM_CGROUP_PAGECACHE_STAT_NSTATS; i++) {
+			per_cpu(memcg->pagecache_stat->count[i], cpu) = 0;
+		}
+		spin_unlock(&memcg->pcp_counter_lock);
+	}
+	put_online_cpus();
+	return 0;
+}
+#endif
+
 static u64 mem_cgroup_move_charge_read(struct cgroup *cgrp,
 					struct cftype *cft)
 {
@@ -5599,6 +5673,22 @@ static int memcg_stat_show(struct cgroup *cont, struct cftype *cft,
 	return 0;
 }
 
+#ifdef CONFIG_MEMCG_PAGECACHE_HIT
+//static int memcg_pagecache_stat_show(struct seq_file *m, void *v)
+static int memcg_pagecache_stat_show(struct cgroup *cont, struct cftype *cft,
+				struct seq_file *m)
+{
+	struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
+	unsigned int i;
+
+	for (i = 0; i < MEM_CGROUP_PAGECACHE_STAT_NSTATS; i++) {
+		seq_printf(m, "%s %ld\n", mem_cgroup_pagecache_stat_names[i],
+			   mem_cgroup_read_pagecache_stat(memcg, i));
+	}
+	return 0;
+}
+#endif
+
 static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft)
 {
 	struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
@@ -6134,6 +6224,13 @@ static struct cftype mem_cgroup_files[] = {
 	},
 #endif
 #endif
+#ifdef CONFIG_MEMCG_PAGECACHE_HIT
+	{
+		.name = "pagecache_stat",
+		.trigger = mem_cgroup_pagecache_stat_reset,
+		.read_seq_string = memcg_pagecache_stat_show,
+	},
+#endif
 	{ },	/* terminate */
 };
 
@@ -6219,6 +6316,11 @@ static struct mem_cgroup *mem_cgroup_alloc(void)
 	memcg->stat = alloc_percpu(struct mem_cgroup_stat_cpu);
 	if (!memcg->stat)
 		goto out_free;
+#ifdef CONFIG_MEMCG_PAGECACHE_HIT
+	memcg->pagecache_stat = alloc_percpu(struct mem_cgroup_pagecache_stat_cpu);
+	if (!memcg->pagecache_stat)
+		goto out_free;
+#endif
 	spin_lock_init(&memcg->pcp_counter_lock);
 	return memcg;