hugetlb: abort a hugepage pool resize if a signal is pending

If a user asks for a hugepage pool resize but specified a large number,
the machine can begin trashing.  In response, they might hit ctrl-c but
signals are ignored and the pool resize continues until it fails an
allocation.  This can take a considerable amount of time so this patch
aborts a pool resize if a signal is pending.

Suggested by Dave Hansen.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 6df8065039eb..65f38c218207 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1278,6 +1278,9 @@ static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count,
                 if (!ret)
                         goto out;
 
+                /* Bail for signals. Probably ctrl-c from user */
+                if (signal_pending(current))
+                        goto out;
         }
 
         /*