diff options
| author | Hugh Dickins <hughd@google.com> | 2012-02-09 02:13:40 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-02-09 04:03:51 +0100 |
| commit | b9980cdcf2524c5fe15d8cbae9c97b3ed6385563 (patch) | |
| tree | 18295d2fe860bcdaae87138b44023abadfcd24d4 /mm/huge_memory.c | |
| parent | drivers/leds/leds-lm3530.c: fix setting pltfm->als_vmax (diff) | |
| download | linux-b9980cdcf2524c5fe15d8cbae9c97b3ed6385563.tar.xz linux-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/huge_memory.c')
| -rw-r--r-- | mm/huge_memory.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index b3ffc21ce801..91d3efb25d15 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2083,7 +2083,7 @@ 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 */ @@ -2113,7 +2113,7 @@ 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; |