[PATCH RESEND 6/6] memcontrol-v1: add ksm_profit in cgroup/memory.ksm_stat

[xu xin <xu.xin.sc@gmail.com>]

Users can obtain ksm_profit of a cgroup just by:

/ # cat /sys/fs/cgroup/memory.ksm_stat
ksm_rmap_items 76800
ksm_zero_pages 0
ksm_merging_pages 76800
ksm_profit 309657600

Current implementation supports cgroup v1 temporarily; cgroup v2
compatibility is planned for future versions.

Signed-off-by: xu xin <xu.xin16@zte.com.cn>
---
 mm/memcontrol-v1.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c
index 7ee38d633d85..2cf2823c5514 100644
--- a/mm/memcontrol-v1.c
+++ b/mm/memcontrol-v1.c
@@ -1827,6 +1827,7 @@ struct memcg_ksm_stat {
 	unsigned long ksm_rmap_items;
 	long ksm_zero_pages;
 	unsigned long ksm_merging_pages;
+	long ksm_profit;
 };
 
 static int evaluate_memcg_ksm_stat(struct task_struct *task, void *arg)
@@ -1839,6 +1840,7 @@ static int evaluate_memcg_ksm_stat(struct task_struct *task, void *arg)
 		ksm_stat->ksm_rmap_items += mm->ksm_rmap_items;
 		ksm_stat->ksm_zero_pages += mm_ksm_zero_pages(mm);
 		ksm_stat->ksm_merging_pages += mm->ksm_merging_pages;
+		ksm_stat->ksm_profit += ksm_process_profit(mm);
 		mmput(mm);
 	}
 
@@ -1854,6 +1856,7 @@ static int memcg_ksm_stat_show(struct seq_file *m, void *v)
 	ksm_stat.ksm_rmap_items = 0;
 	ksm_stat.ksm_zero_pages = 0;
 	ksm_stat.ksm_merging_pages = 0;
+	ksm_stat.ksm_profit = 0;
 
 	/* summing all processes'ksm statistic items of this cgroup hierarchy */
 	mem_cgroup_scan_tasks(memcg, evaluate_memcg_ksm_stat, &ksm_stat);
@@ -1861,6 +1864,7 @@ static int memcg_ksm_stat_show(struct seq_file *m, void *v)
 	seq_printf(m, "ksm_rmap_items %lu\n", ksm_stat.ksm_rmap_items);
 	seq_printf(m, "ksm_zero_pages %ld\n", ksm_stat.ksm_zero_pages);
 	seq_printf(m, "ksm_merging_pages %ld\n", ksm_stat.ksm_merging_pages);
+	seq_printf(m, "ksm_profit %ld\n", ksm_stat.ksm_profit);
 
 	return 0;
 }
-- 
2.39.3