From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 7 Jun 2007 08:34:58 -0700 From: Andrew Morton Subject: Re: 2.6.22-rc4-mm1 Message-Id: <20070607083458.a3fc7737.akpm@linux-foundation.org> In-Reply-To: <20070607214706.3efc5870.kamezawa.hiroyu@jp.fujitsu.com> References: <20070606020737.4663d686.akpm@linux-foundation.org> <20070607214706.3efc5870.kamezawa.hiroyu@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: KAMEZAWA Hiroyuki Cc: linux-kernel@vger.kernel.org, clameter@sgi.com, "linux-mm@kvack.org" , Matt Mackall , David Rientjes List-ID: On Thu, 7 Jun 2007 21:47:06 +0900 KAMEZAWA Hiroyuki wrote: > Question. > > While writing memory unplug, I noticed this code. > == > static int > fixup_anon_page(pte_t *pte, unsigned long start, unsigned long end, void *priv) > { > struct vm_area_struct *vma = priv; > struct page *page = vm_normal_page(vma, start, *pte); > > if (page && PageAnon(page)) > page->index = linear_page_index(vma, start); > > return 0; > } > > static int fixup_anon_pages(struct vm_area_struct *vma) > { > struct mm_walk walk = { > .pte_entry = fixup_anon_page, > }; > > return walk_page_range(vma->vm_mm, > vma->vm_start, vma->vm_end, &walk, vma); > } I assume the above is your code - it's not in the tree? > > I think that 'pte' passed to fixup_anon_page() by walk_page_range() > is not guaranteed to be 'Present'. yup - the pagewalker only checks for !pte_none(). > Then, vm_normal_page() will show print_bad_pte(). > If this never occur now, I'll add my own check code for memory migration by kernel here. Yes, you'll need to perform additional filtering where appropriate. > (Sorry, I can't find who should be CCed.) Matt and David did most of the work here. -- 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