mm: make vm_brk killable
Now that all the callers handle vm_brk failure we can change it wait for
mmap_sem killable to help oom_reaper to not get blocked just because
vm_brk gets blocked behind mmap_sem readers.
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/mmap.c b/mm/mmap.c
index ca292a7..d3d9a94 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2712,12 +2712,9 @@
unsigned long ret;
bool populate;
- /*
- * XXX not all users are chcecking the return value, convert
- * to down_write_killable after they are able to cope with
- * error
- */
- down_write(&mm->mmap_sem);
+ if (down_write_killable(&mm->mmap_sem))
+ return -EINTR;
+
ret = do_brk(addr, len);
populate = ((mm->def_flags & VM_LOCKED) != 0);
up_write(&mm->mmap_sem);