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authorKonstantin Khlebnikov <koct9i@gmail.com>2014-08-06 16:06:36 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-08-06 18:01:19 -0700
commit82f71ae4a2b829a25971bdf54b4d0d3d69d3c8b7 (patch)
tree2b304d094f4468b74a1c581eb9d6f9affa63a146 /mm/mmap.c
parent77142517990fd3d982678c2945ea2c4188ec5f9a (diff)
downloadlwn-82f71ae4a2b829a25971bdf54b4d0d3d69d3c8b7.tar.gz
lwn-82f71ae4a2b829a25971bdf54b4d0d3d69d3c8b7.zip
mm: catch memory commitment underflow
Print a warning (if CONFIG_DEBUG_VM=y) when memory commitment becomes too negative. This shouldn't happen any more - the previous two patches fixed the committed_as underflow issues. [akpm@linux-foundation.org: use VM_WARN_ONCE, per Dave] Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/mmap.c')
-rw-r--r--mm/mmap.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index 129b847d30cc..64c9d736155c 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -31,6 +31,7 @@
#include <linux/mempolicy.h>
#include <linux/rmap.h>
#include <linux/mmu_notifier.h>
+#include <linux/mmdebug.h>
#include <linux/perf_event.h>
#include <linux/audit.h>
#include <linux/khugepaged.h>
@@ -134,6 +135,10 @@ int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin)
{
unsigned long free, allowed, reserve;
+ VM_WARN_ONCE(percpu_counter_read(&vm_committed_as) <
+ -(s64)vm_committed_as_batch * num_online_cpus(),
+ "memory commitment underflow");
+
vm_acct_memory(pages);
/*