From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sun, 28 Jan 2007 22:40:02 -0800 From: Andrew Morton Subject: Re: [patch] mm: mremap correct rmap accounting Message-Id: <20070128224002.3e7da788.akpm@osdl.org> In-Reply-To: <45BD6A7B.7070501@yahoo.com.au> References: <45B61967.5000302@yahoo.com.au> <45BD6A7B.7070501@yahoo.com.au> 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: Hugh Dickins , Linux Memory Management , Ralf Baechle , Linus Torvalds List-ID: On Mon, 29 Jan 2007 14:31:07 +1100 Nick Piggin wrote: > When mremap()ing virtual addresses, some architectures (read: MIPS) switches > underlying pages if encountering ZERO_PAGE(old_vaddr) != ZERO_PAGE(new_vaddr). > > The problem is that the refcount and mapcount remain on the old page, while > the actual pte is switched to the new one. This would counter underruns and > confuse the rmap code. umm, that sounds fairly fatal. For how long has this bug been present? -- 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