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authorDavid Rientjes <rientjes@google.com>2015-04-14 15:48:24 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-14 16:49:06 -0700
commit02057967b5d3b77ed47f06ee8fe98e2687fdf18b (patch)
tree34bf831d910f420dff383af2758e1268b30e8360
parent11d83360452ea2a95e699da01f8e1bcc4676a5de (diff)
mm, hugetlb: abort __get_user_pages if current has been oom killed
If __get_user_pages() is faulting a significant number of hugetlb pages, usually as the result of mmap(MAP_LOCKED), it can potentially allocate a very large amount of memory. If the process has been oom killed, this will cause a lot of memory to potentially deplete memory reserves. In the same way that commit 4779280d1ea4 ("mm: make get_user_pages() interruptible") aborted for pending SIGKILLs when faulting non-hugetlb memory, based on the premise of commit 462e00cc7151 ("oom: stop allocating user memory if TIF_MEMDIE is set"), hugetlb page faults now terminate when the process has been oom killed. Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Greg Thelen <gthelen@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Acked-by: "Kirill A. Shutemov" <kirill@shutemov.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/hugetlb.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index caad3c5a926f..8874c8ad55aa 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3278,6 +3278,15 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
struct page *page;
/*
+ * If we have a pending SIGKILL, don't keep faulting pages and
+ * potentially allocating memory.
+ */
+ if (unlikely(fatal_signal_pending(current))) {
+ remainder = 0;
+ break;
+ }
+
+ /*
* Some archs (sparc64, sh*) have multiple pte_ts to
* each hugepage. We have to make sure we get the
* first, for the page indexing below to work.