From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with SMTP id 27B3C6B004F for ; Tue, 30 Jun 2009 19:44:31 -0400 (EDT) Received: from m6.gw.fujitsu.co.jp ([10.0.50.76]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n5UNjrAs013937 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Wed, 1 Jul 2009 08:45:53 +0900 Received: from smail (m6 [127.0.0.1]) by outgoing.m6.gw.fujitsu.co.jp (Postfix) with ESMTP id 0A40845DE50 for ; Wed, 1 Jul 2009 08:45:53 +0900 (JST) Received: from s6.gw.fujitsu.co.jp (s6.gw.fujitsu.co.jp [10.0.50.96]) by m6.gw.fujitsu.co.jp (Postfix) with ESMTP id D87D745DE4F for ; Wed, 1 Jul 2009 08:45:52 +0900 (JST) Received: from s6.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s6.gw.fujitsu.co.jp (Postfix) with ESMTP id 9B2741DB8040 for ; Wed, 1 Jul 2009 08:45:52 +0900 (JST) Received: from ml13.s.css.fujitsu.com (ml13.s.css.fujitsu.com [10.249.87.103]) by s6.gw.fujitsu.co.jp (Postfix) with ESMTP id 4F9541DB8038 for ; Wed, 1 Jul 2009 08:45:52 +0900 (JST) From: KOSAKI Motohiro Subject: Re: BUG: Bad page state [was: Strange oopses in 2.6.30] In-Reply-To: <20090630163456.GA6689@csn.ul.ie> References: <20090630092847.A730.A69D9226@jp.fujitsu.com> <20090630163456.GA6689@csn.ul.ie> Message-Id: <20090701084324.85C5.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Wed, 1 Jul 2009 08:45:51 +0900 (JST) Sender: owner-linux-mm@kvack.org To: Mel Gorman Cc: kosaki.motohiro@jp.fujitsu.com, Lee Schermerhorn , Jiri Slaby , Maxim Levitsky , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , Christoph Lameter , Pekka Enberg , Rik van Riel List-ID: > On Tue, Jun 30, 2009 at 09:31:04AM +0900, KOSAKI Motohiro wrote: > > > -static inline int free_pages_check(struct page *page) > > > -{ > > > +static inline int free_pages_check(struct page *page, int wasMlocked) > > > +{ > > > + if (unlikely(wasMlocked)) { > > > + WARN_ONCE(1, KERN_WARNING > > > + "Page flag mlocked set for process %s at pfn:%05lx\n" > > > + "page:%p flags:0x%lX\n", > > > > 0x%lX is a bit redundunt. > > %lX insert "0x" string by itself, I think. > > > > /me slaps self > > As hnaz pointed out to me on IRC, %#lX would have done the job of > putting in the 0x automatically. No. it's my fault. my last mail has typo (i forgot to write '#'), sorry. > > ==== CUT HERE ==== > mm: Warn once when a page is freed with PG_mlocked set > > When a page is freed with the PG_mlocked set, it is considered an unexpected > but recoverable situation. A counter records how often this event happens > but it is easy to miss that this event has occured at all. This patch warns > once when PG_mlocked is set to prompt debuggers to check the counter to see > how often it is happening. > > Signed-off-by: Mel Gorman > --- > mm/page_alloc.c | 16 ++++++++++++---- > 1 file changed, 12 insertions(+), 4 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 5d714f8..519ea6e 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -495,8 +495,16 @@ static inline void free_page_mlock(struct page *page) > static void free_page_mlock(struct page *page) { } > #endif > > -static inline int free_pages_check(struct page *page) > -{ > +static inline int free_pages_check(struct page *page, int wasMlocked) > +{ > + if (unlikely(wasMlocked)) { > + WARN_ONCE(1, KERN_WARNING > + "Page flag mlocked set for process %s at pfn:%05lx\n" > + "page:%p flags:%#lX\n", > + current->comm, page_to_pfn(page), > + page, page->flags|__PG_MLOCKED); > + } > + > if (unlikely(page_mapcount(page) | > (page->mapping != NULL) | > (atomic_read(&page->_count) != 0) | > @@ -562,7 +570,7 @@ static void __free_pages_ok(struct page *page, unsigned int order) > kmemcheck_free_shadow(page, order); > > for (i = 0 ; i < (1 << order) ; ++i) > - bad += free_pages_check(page + i); > + bad += free_pages_check(page + i, wasMlocked); > if (bad) > return; > > @@ -1027,7 +1035,7 @@ static void free_hot_cold_page(struct page *page, int cold) > > if (PageAnon(page)) > page->mapping = NULL; > - if (free_pages_check(page)) > + if (free_pages_check(page, wasMlocked)) > return; > > if (!PageHighMem(page)) { OK, looks fine. Reviewed-by: KOSAKI Motohiro -- 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