Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933087Ab2FVVGo (ORCPT ); Fri, 22 Jun 2012 17:06:44 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:60616 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755697Ab2FVVGn (ORCPT ); Fri, 22 Jun 2012 17:06:43 -0400 Date: Fri, 22 Jun 2012 14:06:40 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Dave Jones cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrea Arcangeli , Sasha Levin , Andrew Morton Subject: Re: [patch v2] mm, thp: print useful information when mmap_sem is unlocked in zap_pmd_range In-Reply-To: Message-ID: References: <20120606165330.GA27744@redhat.com> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1187 Lines: 30 On Mon, 11 Jun 2012, David Rientjes wrote: > 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 from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/