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| author | Christoph Lameter <clameter@engr.sgi.com> | 2006-02-04 23:27:55 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-02-05 11:06:53 -0800 |
| commit | 64b4a954b03a1153fb8ae38d6ffbd991e01a1e80 (patch) | |
| tree | 0436a6f23e46d9fcb6caf5b1216fe212be3fbc3f /mm/hugetlb.c | |
| parent | fe1dcbc4f311c2e6c23b33c0fa8572461618ab3e (diff) | |
| download | op-kernel-dev-64b4a954b03a1153fb8ae38d6ffbd991e01a1e80.zip op-kernel-dev-64b4a954b03a1153fb8ae38d6ffbd991e01a1e80.tar.gz | |
[PATCH] hugetlb: add comment explaining reasons for Bus Errors
I just spent some time researching a Bus Error. Turns out that the huge
page fault handler can return VM_FAULT_SIGBUS for various conditions where
no huge page is available.
Add a note explaining the reasoning in the source.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Acked-by: William Lee Irwin III <wli@holomorphy.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm/hugetlb.c')
| -rw-r--r-- | mm/hugetlb.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index b21d78c..ceb3ebb 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -444,6 +444,15 @@ retry: page = alloc_huge_page(vma, address); if (!page) { hugetlb_put_quota(mapping); + /* + * No huge pages available. So this is an OOM + * condition but we do not want to trigger the OOM + * killer, so we return VM_FAULT_SIGBUS. + * + * A program using hugepages may fault with Bus Error + * because no huge pages are available in the cpuset, per + * memory policy or because all are in use! + */ goto out; } |
