From a2ac52952bc5563fbd7240d9024c45451451b51f Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Thu, 26 Jun 2014 10:42:43 +1000 Subject: [PATCH] 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. Signed-off-by: Konstantin Khlebnikov Cc: Hugh Dickins Signed-off-by: Andrew Morton --- mm/mmap.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/mm/mmap.c b/mm/mmap.c index 129b847d30cc..d3decd9cec8c 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -134,6 +134,12 @@ int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin) { unsigned long free, allowed, reserve; +#ifdef CONFIG_DEBUG_VM + WARN_ONCE(percpu_counter_read(&vm_committed_as) < + -(s64)vm_committed_as_batch * num_online_cpus(), + "memory commitment underflow"); +#endif + vm_acct_memory(pages); /* -- 2.39.5