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| author | Hugh Dickins <hughd@google.com> | 2012-02-08 17:13:40 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-02-13 11:17:01 -0800 |
| commit | d0a77dc1abbe11f8d14a6cce8632d85ff79f3636 (patch) | |
| tree | d0076952889b5f74da9c48f67a76166c5fcca47d | |
| parent | a7d2576c858c397282602fe92adf8c8ac9d6a0e0 (diff) | |
| download | lwn-d0a77dc1abbe11f8d14a6cce8632d85ff79f3636.tar.gz lwn-d0a77dc1abbe11f8d14a6cce8632d85ff79f3636.zip | |
mm: fix UP THP spin_is_locked BUGs
commit b9980cdcf2524c5fe15d8cbae9c97b3ed6385563 upstream.
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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | mm/huge_memory.c | 4 | ||||
| -rw-r--r-- | mm/swap.c | 2 |
2 files changed, 3 insertions, 3 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 36b3d988b4ef..33141f527369 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2064,7 +2064,7 @@ static void collect_mm_slot(struct mm_slot *mm_slot) { struct mm_struct *mm = mm_slot->mm; - VM_BUG_ON(!spin_is_locked(&khugepaged_mm_lock)); + VM_BUG_ON(NR_CPUS != 1 && !spin_is_locked(&khugepaged_mm_lock)); if (khugepaged_test_exit(mm)) { /* free mm_slot */ @@ -2094,7 +2094,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, int progress = 0; VM_BUG_ON(!pages); - VM_BUG_ON(!spin_is_locked(&khugepaged_mm_lock)); + VM_BUG_ON(NR_CPUS != 1 && !spin_is_locked(&khugepaged_mm_lock)); if (khugepaged_scan.mm_slot) mm_slot = khugepaged_scan.mm_slot; diff --git a/mm/swap.c b/mm/swap.c index a91caf754d9b..55b266dcfbeb 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -667,7 +667,7 @@ 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); |