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-rw-r--r--mm/page_alloc.c29
1 files changed, 27 insertions, 2 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 941b802e11ec..d156310aedeb 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -249,6 +249,7 @@ compound_page_dtor * const compound_page_dtors[] = {
int min_free_kbytes = 1024;
int user_min_free_kbytes = -1;
+int watermark_scale_factor = 10;
static unsigned long __meminitdata nr_kernel_pages;
static unsigned long __meminitdata nr_all_pages;
@@ -6347,8 +6348,17 @@ static void __setup_per_zone_wmarks(void)
zone->watermark[WMARK_MIN] = tmp;
}
- zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2);
- zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
+ /*
+ * Set the kswapd watermarks distance according to the
+ * scale factor in proportion to available memory, but
+ * ensure a minimum size on small systems.
+ */
+ tmp = max_t(u64, tmp >> 2,
+ mult_frac(zone->managed_pages,
+ watermark_scale_factor, 10000));
+
+ zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + tmp;
+ zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + tmp * 2;
__mod_zone_page_state(zone, NR_ALLOC_BATCH,
high_wmark_pages(zone) - low_wmark_pages(zone) -
@@ -6489,6 +6499,21 @@ int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write,
return 0;
}
+int watermark_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
int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write,
void __user *buffer, size_t *length, loff_t *ppos)