diff options
| author | David Rientjes <rientjes@google.com> | 2012-06-20 12:53:00 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-06-20 14:39:35 -0700 |
| commit | e0897d75f0b22e8c3a7287a48548c5686ef73447 (patch) | |
| tree | 7c6e96b8f9e95ba81e322833363398df119102e0 /mm/memory.c | |
| parent | 436814e61f5c526ed123853a9bf63fb2ff4ff94b (diff) | |
| download | lwn-e0897d75f0b22e8c3a7287a48548c5686ef73447.tar.gz lwn-e0897d75f0b22e8c3a7287a48548c5686ef73447.zip | |
mm, thp: print useful information when mmap_sem is unlocked in zap_pmd_range
Andrea asked for addr, end, vma->vm_start, and vma->vm_end to be emitted
when !rwsem_is_locked(&tlb->mm->mmap_sem). Otherwise, debugging the
underlying issue is more difficult.
Suggested-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/mm/memory.c b/mm/memory.c index 1b7dc662bf9f..8762c4f915fc 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1225,7 +1225,15 @@ static inline unsigned long zap_pmd_range(struct mmu_gather *tlb, next = pmd_addr_end(addr, end); if (pmd_trans_huge(*pmd)) { if (next - addr != HPAGE_PMD_SIZE) { - VM_BUG_ON(!rwsem_is_locked(&tlb->mm->mmap_sem)); +#ifdef CONFIG_DEBUG_VM + if (!rwsem_is_locked(&tlb->mm->mmap_sem)) { + pr_err("%s: mmap_sem is unlocked! addr=0x%lx end=0x%lx vma->vm_start=0x%lx vma->vm_end=0x%lx\n", + __func__, addr, end, + vma->vm_start, + vma->vm_end); + BUG(); + } +#endif split_huge_page_pmd(vma->vm_mm, pmd); } else if (zap_huge_pmd(tlb, vma, pmd, addr)) goto next; |