From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 28 May 2008 20:19:29 -0700 From: Andrew Morton Subject: Re: [patch] hugetlb: fix lockdep error Message-Id: <20080528201929.cf766924.akpm@linux-foundation.org> In-Reply-To: <20080529030745.GG3258@wotan.suse.de> References: <20080529015956.GC3258@wotan.suse.de> <20080528191657.ba5f283c.akpm@linux-foundation.org> <20080529022919.GD3258@wotan.suse.de> <20080528193808.6e053dac.akpm@linux-foundation.org> <20080529030745.GG3258@wotan.suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Nick Piggin Cc: agl@us.ibm.com, nacc@us.ibm.com, Linux Memory Management List , kosaki.motohiro@jp.fujitsu.com List-ID: On Thu, 29 May 2008 05:07:45 +0200 Nick Piggin wrote: > > > mm/hugetlb.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > Index: linux-2.6/mm/hugetlb.c > > > =================================================================== > > > --- linux-2.6.orig/mm/hugetlb.c > > > +++ linux-2.6/mm/hugetlb.c > > > @@ -785,7 +785,7 @@ int copy_hugetlb_page_range(struct mm_st > > > continue; > > > > > > spin_lock(&dst->page_table_lock); > > > - spin_lock(&src->page_table_lock); > > > + spin_lock_nested(&src->page_table_lock, SINGLE_DEPTH_NESTING); > > > if (!huge_pte_none(huge_ptep_get(src_pte))) { > > > if (cow) > > > huge_ptep_set_wrprotect(src, addr, src_pte); > > > > Confused. This code has been there since October 2005. Why are we > > only seeing lockdep warnings now? > > Can't say. Haven't looked at hugetlb code or tested it much until now. > I am using a recent libhugetlbfs test suite, FWIW. I don't believe that it's possible that nobody has run that test suite with lockdep enabled at any time in the past three years. If that's really the case then perhaps we should make the ability to recite Documentation/SubmitChecklist in three languages a prerequisite for MM development. (sheesh) -- 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: email@kvack.org