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| author | Hugh Dickins <hughd@google.com> | 2012-02-08 17:13:40 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-02-08 19:03:51 -0800 |
| commit | b9980cdcf2524c5fe15d8cbae9c97b3ed6385563 (patch) | |
| tree | 18295d2fe860bcdaae87138b44023abadfcd24d4 /mm/swap.c | |
| parent | ec44fd429879f7d4f28021f1a7f9fb0b5f831aab (diff) | |
| download | lwn-b9980cdcf2524c5fe15d8cbae9c97b3ed6385563.tar.gz lwn-b9980cdcf2524c5fe15d8cbae9c97b3ed6385563.zip | |
mm: fix UP THP spin_is_locked BUGs
Fix CONFIG_TRANSPARENT_HUGEPAGE=y CONFIG_SMP=n CONFIG_DEBUG_VM=y
CONFIG_DEBUG_SPINLOCK=n kernel: spin_is_locked() is then always false,
and so triggers some BUGs in Transparent HugePage codepaths.
asm-generic/bug.h mentions this problem, and provides a WARN_ON_SMP(x);
but being too lazy to add VM_BUG_ON_SMP, BUG_ON_SMP, WARN_ON_SMP_ONCE,
VM_WARN_ON_SMP_ONCE, just test NR_CPUS != 1 in the existing VM_BUG_ONs.
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/swap.c')
| -rw-r--r-- | mm/swap.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/swap.c b/mm/swap.c index b0f529b38979..fff1ff7fb9ad 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -659,7 +659,7 @@ void lru_add_page_tail(struct zone* zone, VM_BUG_ON(!PageHead(page)); VM_BUG_ON(PageCompound(page_tail)); VM_BUG_ON(PageLRU(page_tail)); - VM_BUG_ON(!spin_is_locked(&zone->lru_lock)); + VM_BUG_ON(NR_CPUS != 1 && !spin_is_locked(&zone->lru_lock)); SetPageLRU(page_tail); |