Update the toptier_scale_factor via sysctl. This variable determines
when kswapd wakes up to recalaim toptier memory from those mem cgroups
exceeding their toptier memory limit.
Signed-off-by: Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx>
---
include/linux/mm.h | 4 ++++
include/linux/mmzone.h | 2 ++
kernel/sysctl.c | 10 ++++++++++
mm/page_alloc.c | 15 +++++++++++++++
mm/vmstat.c | 2 ++
5 files changed, 33 insertions(+)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index a43429d51fc0..af39e221d0f9 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3179,6 +3179,10 @@ static inline bool debug_guardpage_enabled(void) { return false; }
static inline bool page_is_guard(struct page *page) { return false; }
#endif /* CONFIG_DEBUG_PAGEALLOC */
+#ifdef CONFIG_MIGRATION
+extern int toptier_scale_factor;
+#endif
+
#if MAX_NUMNODES > 1
void __init setup_nr_node_ids(void);
#else
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 4ee0073d255f..789319dffe1c 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -1003,6 +1003,8 @@ int min_free_kbytes_sysctl_handler(struct ctl_table *, int, void *, size_t *,
loff_t *);
int watermark_scale_factor_sysctl_handler(struct ctl_table *, int, void *,
size_t *, loff_t *);
+int toptier_scale_factor_sysctl_handler(struct ctl_table *, int,
+ void __user *, size_t *, loff_t *);
extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES];
int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int, void *,
size_t *, loff_t *);
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 57f89fe1b0f2..e97c974f37b7 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -112,6 +112,7 @@ static int sixty = 60;
#endif
static int __maybe_unused neg_one = -1;
+static int __maybe_unused one = 1;
static int __maybe_unused two = 2;
static int __maybe_unused three = 3;
static int __maybe_unused four = 4;
@@ -2956,6 +2957,15 @@ static struct ctl_table vm_table[] = {
.extra1 = SYSCTL_ONE,
.extra2 = &one_thousand,
},
+ {
+ .procname = "toptier_scale_factor",
+ .data = &toptier_scale_factor,
+ .maxlen = sizeof(toptier_scale_factor),
+ .mode = 0644,
+ .proc_handler = toptier_scale_factor_sysctl_handler,
+ .extra1 = &one,
+ .extra2 = &ten_thousand,
+ },
{
.procname = "percpu_pagelist_fraction",
.data = &percpu_pagelist_fraction,
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 20f3caee60f3..91212a837d8e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -8094,6 +8094,21 @@ int watermark_scale_factor_sysctl_handler(struct ctl_table *table, int write,
return 0;
}
+int toptier_scale_factor_sysctl_handler(struct ctl_table *table, int write,
+ void __user *buffer, size_t *length, loff_t *ppos)
+{
+ int rc;
+
+ rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
+ if (rc)
+ return rc;
+
+ if (write)
+ setup_per_zone_wmarks();
+
+ return 0;
+}
+
#ifdef CONFIG_NUMA
static void setup_min_unmapped_ratio(void)
{
diff --git a/mm/vmstat.c b/mm/vmstat.c
index b59efbcaef4e..c581753cf076 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1658,6 +1658,7 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
"\n min %lu"
"\n low %lu"
"\n high %lu"
+ "\n toptier %lu"
"\n spanned %lu"
"\n present %lu"
"\n managed %lu",
@@ -1665,6 +1666,7 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
min_wmark_pages(zone),
low_wmark_pages(zone),
high_wmark_pages(zone),
+ toptier_wmark_pages(zone),
zone->spanned_pages,
zone->present_pages,
zone_managed_pages(zone));
--
2.20.1
