[PATCH v2 4/9] memcontrol: add ksm_zero_pages in cgroup/memory.ksm_stat

[xu . xin . sc]

From: xu xin <xu.xin16@xxxxxxxxxx>

Users can obtain ksm_zero_pages of a cgroup just by:

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

Signed-off-by: xu xin <xu.xin16@xxxxxxxxxx>
---
 mm/memcontrol.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 69521a66639b..509098093bbd 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -63,6 +63,7 @@
 #include <linux/seq_buf.h>
 #include <linux/sched/isolation.h>
 #include <linux/kmemleak.h>
+#include <linux/ksm.h>
 #include "internal.h"
 #include <net/sock.h>
 #include <net/ip.h>
@@ -4391,6 +4392,7 @@ static int memory_numa_stat_show(struct seq_file *m, void *v)
 #ifdef CONFIG_KSM
 struct memcg_ksm_stat {
 	unsigned long ksm_rmap_items;
+	long ksm_zero_pages;
 };
 
 static int evaluate_memcg_ksm_stat(struct task_struct *task, void *arg)
@@ -4401,6 +4403,7 @@ static int evaluate_memcg_ksm_stat(struct task_struct *task, void *arg)
 	mm = get_task_mm(task);
 	if (mm) {
 		ksm_stat->ksm_rmap_items += mm->ksm_rmap_items;
+		ksm_stat->ksm_zero_pages += mm_ksm_zero_pages(mm);
 		mmput(mm);
 	}
 
@@ -4414,9 +4417,12 @@ static int memcg_ksm_stat_show(struct seq_file *m, void *v)
 
 	/* Initialization */
 	ksm_stat.ksm_rmap_items = 0;
+	ksm_stat.ksm_zero_pages = 0;
+
 	/* summing all processes'ksm statistic items of this cgroup hierarchy */
 	mem_cgroup_scan_tasks(memcg, evaluate_memcg_ksm_stat, &ksm_stat);
 	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);
 
 	return 0;
 }
-- 
2.15.2