From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx136.postini.com [74.125.245.136]) by kanga.kvack.org (Postfix) with SMTP id A60176B01F7 for ; Mon, 12 Dec 2011 18:12:17 -0500 (EST) Date: Mon, 12 Dec 2011 15:12:15 -0800 From: Andrew Morton Subject: Re: [PATCH] mm: vmscan: try to free orphaned page Message-Id: <20111212151215.2363f5cd.akpm@linux-foundation.org> In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Hillf Danton Cc: Hugh Dickins , David Rientjes , KAMEZAWA Hiroyuki , Andrea Arcangeli , linux-mm@kvack.org, LKML On Mon, 12 Dec 2011 20:24:39 +0800 Hillf Danton wrote: > If the orphaned page has no buffer attached at the moment, we clean it up by > hand, then it has the chance to progress the freeing trip. > > Signed-off-by: Hillf Danton > --- > > --- a/mm/vmscan.c Sun Dec 4 13:10:08 2011 > +++ b/mm/vmscan.c Mon Dec 12 20:12:44 2011 > @@ -487,12 +487,10 @@ static pageout_t pageout(struct page *pa > * Some data journaling orphaned pages can have > * page->mapping == NULL while being dirty with clean buffers. > */ > - if (page_has_private(page)) { > - if (try_to_free_buffers(page)) { > - ClearPageDirty(page); > - printk("%s: orphaned page\n", __func__); > - return PAGE_CLEAN; > - } > + if (!page_has_private(page) || try_to_free_buffers(page)) { > + ClearPageDirty(page); > + printk(KERN_INFO "%s: orphaned page\n", __func__); > + return PAGE_CLEAN; > } > return PAGE_KEEP; > } So if we find a dirty pagecache page with nothing at ->private, you're suggesting that we simply mark it clean and free it. afacit it would be a bug for a page to be in that state. What prompted this patch? I assume you've not encountered pages in this state in your testing because if you had, that printk wouldn't still be in there! A brief bit of googling indicates that nobody has seen the "pageout: orphaned page" warning for five years. -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org