Messages in this thread Patch in this message | | | Date | Mon, 9 Mar 2015 13:07:39 -0700 (PDT) | From | David Rientjes <> | Subject | [patch v3] mm, hugetlb: abort __get_user_pages if current has been oom killed |
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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.
Cc: Greg Thelen <gthelen@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Acked-by: "Kirill A. Shutemov" <kirill@shutemov.name> Signed-off-by: David Rientjes <rientjes@google.com> --- v3: tweak changelog per Greg
mm/hugetlb.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -3276,6 +3276,15 @@ 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.
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