From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 27 Feb 2008 16:14:08 -0800 (PST) From: Christoph Lameter Subject: Re: [patch 2/6] mmu_notifier: Callbacks to invalidate address ranges In-Reply-To: <20080228001104.GB8091@v2.random> Message-ID: References: <20080215064859.384203497@sgi.com> <20080215064932.620773824@sgi.com> <200802201008.49933.nickpiggin@yahoo.com.au> <20080228001104.GB8091@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: Nick Piggin , akpm@linux-foundation.org, Robin Holt , Avi Kivity , Izik Eidus , kvm-devel@lists.sourceforge.net, Peter Zijlstra , general@lists.openfabrics.org, Steve Wise , Roland Dreier , Kanoj Sarcar , steiner@sgi.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, daniel.blueman@quadrics.com List-ID: On Thu, 28 Feb 2008, Andrea Arcangeli wrote: > > 3. Keep the refcount elevated until pages are freed in another execution > > context. > > Page refcount is not enough (the mmu_notifier_release will run in > another cpu the moment after i_mmap_lock is unlocked) but mm_users may > prevent us to change the i_mmap_lock to a mutex, but it'll slowdown > truncate as it'll have to drop the lock and restart the radix tree > walk every time so a change like this better fits as a separate > CONFIG_XPMEM IMHO. Erm. This would also be needed by RDMA etc. -- 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