Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754095Ab2FXTwp (ORCPT ); Sun, 24 Jun 2012 15:52:45 -0400 Received: from mx1.redhat.com ([209.132.183.28]:8136 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752506Ab2FXTwo (ORCPT ); Sun, 24 Jun 2012 15:52:44 -0400 Date: Sun, 24 Jun 2012 15:52:36 -0400 From: Dave Jones To: David Rientjes 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 Message-ID: <20120624195236.GA2153@redhat.com> Mail-Followup-To: Dave Jones , David Rientjes , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrea Arcangeli , Sasha Levin , Andrew Morton References: <20120606165330.GA27744@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1604 Lines: 39 On Fri, Jun 22, 2012 at 02:06:40PM -0700, David Rientjes wrote: > 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. I've had it applied in my local builds for a while, but haven't managed to hit it again recently. Though I've not been doing as many overnight runs this last week or two because temperatures at home have been icky enough without computers belching out hot air (no ac) Dave -- 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/