On a machine with 8GB memory, no any swap device, the /proc/meminfo
CommitLimit shows 4070944KB regardless of overcommit_memory being set to
0/1/2. This patch fixes this bug, and the final effect is as follows:
- when overcommit_memory being set to 0 ## OVERCOMMIT_GUESS
CommitLimit: 8141884 kB
- when overcommit_memory being set to 1 ## OVERCOMMIT_ALWAYS
CommitLimit: 0 kB
- when overcommit_memory being set to 2 ## OVERCOMMIT_NEVER
and overcommit_ratio 50
CommitLimit: 4070940 kB
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Vernon Yang <vernon2gm@xxxxxxxxx>
---
mm/util.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/mm/util.c b/mm/util.c
index bd283e2132e0..4ee93c11dd62 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -932,12 +932,21 @@ int overcommit_kbytes_handler(const struct ctl_table *table, int write, void *bu
}
/*
- * Committed memory limit enforced when OVERCOMMIT_NEVER policy is used
+ * Committed virtual memory limit
+ *
+ * return 0 if OVERCOMMIT_ALWAYS policy is used, otherwise return committed
+ * memory limit enforced if OVERCOMMIT_GUESS or OVERCOMMIT_NEVER policy is used.
*/
unsigned long vm_commit_limit(void)
{
unsigned long allowed;
+ if (sysctl_overcommit_memory == OVERCOMMIT_ALWAYS)
+ return 0;
+
+ if (sysctl_overcommit_memory == OVERCOMMIT_GUESS)
+ return totalram_pages() + total_swap_pages;
+
if (sysctl_overcommit_kbytes)
allowed = sysctl_overcommit_kbytes >> (PAGE_SHIFT - 10);
else
base-commit: 47ac09b91befbb6a235ab620c32af719f8208399
--
2.34.1
