[PATCH v2 4/5] ksm: show ksmd status for auto mode

From: cgel . zte
Date: Fri Aug 12 2022 - 06:13:22 EST


From: xu xin <xu.xin16@xxxxxxxxxx>

Add a sysfs interface of ksmd_status to show some details related
with auto-mode.

Signed-off-by: xu xin <xu.xin16@xxxxxxxxxx>
Signed-off-by: CGEL <cgel.zte@xxxxxxxxx>
---
mm/ksm.c | 42 +++++++++++++++++++++++++++++++++++++++++-
1 file changed, 41 insertions(+), 1 deletion(-)

diff --git a/mm/ksm.c b/mm/ksm.c
index c5fd4f520f4a..478bcf26bfcd 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -307,6 +307,9 @@ unsigned int ksm_auto_threshold = 20;
/* Work in auto-mode. Whether trigger ksmd to compare and merge pages */
static bool auto_triggered;

+/* Count of times that ksmd is triggered due to low free memory */
+static unsigned long triggered_times;
+
#ifdef CONFIG_NUMA
/* Zeroed when merging across nodes is not allowed */
static unsigned int ksm_merge_across_nodes = 1;
@@ -2487,8 +2490,10 @@ static bool should_trigger_ksmd_to_merge(void)

static inline void trigger_ksmd_to_merge(void)
{
- if (!auto_triggered)
+ if (!auto_triggered) {
+ triggered_times++;
auto_triggered = true;
+ }
}

static inline void stop_ksmd_to_merge(void)
@@ -3118,6 +3123,40 @@ static ssize_t run_store(struct kobject *kobj, struct kobj_attribute *attr,
}
KSM_ATTR(run);

+static ssize_t ksmd_status_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ int len = 0;
+ unsigned int mergeable_mms = 0;
+ struct list_head *pos;
+
+ list_for_each(pos, &ksm_mm_head.mm_list)
+ mergeable_mms++;
+
+ if (ksm_run & KSM_RUN_AUTO) {
+ len += sysfs_emit_at(buf, len, "mode: auto\n");
+ len += sysfs_emit_at(buf, len, "auto_triggered: %d\n",
+ auto_triggered);
+ len += sysfs_emit_at(buf, len, "mergeable_mms: %u\n",
+ mergeable_mms);
+ len += sysfs_emit_at(buf, len, "scanning_factor: %u\n",
+ scanning_factor);
+ len += sysfs_emit_at(buf, len, "triggered_times: %lu\n",
+ triggered_times);
+ } else if (ksm_run & KSM_RUN_MERGE) {
+ len += sysfs_emit_at(buf, len, "mode: on\n");
+ len += sysfs_emit_at(buf, len, "mergeable_mms: %u\n",
+ mergeable_mms);
+ } else if (ksm_run & KSM_RUN_UNMERGE)
+ len += sysfs_emit_at(buf, len, "mode: unmerge\n");
+ else
+ len += sysfs_emit_at(buf, len, "mode: off\n");
+
+
+ return len;
+}
+KSM_ATTR_RO(ksmd_status);
+
static ssize_t auto_threshold_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
@@ -3355,6 +3394,7 @@ static struct attribute *ksm_attrs[] = {
&pages_to_scan_attr.attr,
&max_scanning_factor_attr.attr,
&run_attr.attr,
+ &ksmd_status_attr.attr,
&auto_threshold_attr.attr,
&pages_shared_attr.attr,
&pages_sharing_attr.attr,
--
2.25.1