Re: [patch v2] mm, thp: print useful information when mmap_sem is unlocked in zap_pmd_range
From: David Rientjes <rientjes@google.com>
Date: 2012-06-22 21:06:44
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On Mon, 11 Jun 2012, David Rientjes wrote:
quoted hunk ↗ jump to hunk
diff --git a/mm/memory.c b/mm/memory.c --- 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;
This patch is now in Linus' tree so if you are able to hit this issue and capture it again, we should be able to get much more useful information. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>