From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 29 Jan 2008 11:55:10 -0800 (PST) From: Christoph Lameter Subject: Re: [patch 2/6] mmu_notifier: Callbacks to invalidate address ranges In-Reply-To: <20080129162004.GL7233@v2.random> Message-ID: References: <20080128202840.974253868@sgi.com> <20080128202923.849058104@sgi.com> <20080129162004.GL7233@v2.random> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Andrea Arcangeli Cc: Robin Holt , Avi Kivity , Izik Eidus , Nick Piggin , kvm-devel@lists.sourceforge.net, Benjamin Herrenschmidt , Peter Zijlstra , steiner@sgi.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, daniel.blueman@quadrics.com, Hugh Dickins List-ID: On Tue, 29 Jan 2008, Andrea Arcangeli wrote: > > + mmu_notifier(invalidate_range, mm, address, > > + address + PAGE_SIZE - 1, 0); > > page_table = pte_offset_map_lock(mm, pmd, address, &ptl); > > if (likely(pte_same(*page_table, orig_pte))) { > > if (old_page) { > > What's the point of invalidate_range when the size is PAGE_SIZE? And > how can it be right to invalidate_range _before_ ptep_clear_flush? I am not sure. AFAICT you wrote that code. It seems to be okay to invalidate range if you hold mmap_sem writably. In that case no additional faults can happen that would create new ptes. -- 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