[linux-next,5/6] memcontrol-v1: add ksm_merging_pages in cgroup/memory.ksm_stat

Commit Message

[e-mail] April 3, 2025, 5:38 a.m. UTC

From: xu xin <[e-mail]>

Users can obtain ksm_merging_pages of a cgroup just by:

/ # cat /sys/fs/cgroup/memory.ksm_stat
ksm_rmap_items 76800
ksm_zero_pages 0
ksm_merging_pages 1092

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

Signed-off-by: xu xin <[e-mail]>
---
 mm/memcontrol-v1.c | 4 ++++
 1 file changed, 4 insertions(+)

Patch

diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c
index a6eea1deebff..b52f728af963 100644
--- a/mm/memcontrol-v1.c
+++ b/mm/memcontrol-v1.c
@@ -1826,6 +1826,7 @@  static int memcg_numa_stat_show(struct seq_file *m, void *v)
 struct memcg_ksm_stat {
 	unsigned long ksm_rmap_items;
 	long ksm_zero_pages;
+	unsigned long ksm_merging_pages;
 };

 static int evaluate_memcg_ksm_stat(struct task_struct *task, void *arg)
@@ -1837,6 +1838,7 @@  static int evaluate_memcg_ksm_stat(struct task_struct *task, void *arg)
 	if (mm) {
 		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;
 		mmput(mm);
 	}

@@ -1851,12 +1853,14 @@  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;
+	ksm_stat.ksm_merging_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);
+	seq_printf(m, "ksm_merging_pages %ld\n", ksm_stat.ksm_merging_pages);

 	return 0;
 }