From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with ESMTP id A40426B005A for ; Wed, 6 May 2009 12:51:20 -0400 (EDT) Date: Wed, 6 May 2009 17:36:51 +0100 (BST) From: Hugh Dickins Subject: Re: [PATCH 3/6] ksm: change the KSM_REMOVE_MEMORY_REGION ioctl. In-Reply-To: <20090506161424.GC15712@x200.localdomain> Message-ID: References: <1241475935-21162-1-git-send-email-ieidus@redhat.com> <1241475935-21162-2-git-send-email-ieidus@redhat.com> <1241475935-21162-3-git-send-email-ieidus@redhat.com> <1241475935-21162-4-git-send-email-ieidus@redhat.com> <4A00DF9B.1080501@redhat.com> <4A014C7B.9080702@redhat.com> <4A01AC5E.6000906@redhat.com> <20090506161424.GC15712@x200.localdomain> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Chris Wright Cc: Izik Eidus , Rik van Riel , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, aarcange@redhat.com, alan@lxorguk.ukuu.org.uk, device@lanana.org, linux-mm@kvack.org, nickpiggin@yahoo.com.au List-ID: On Wed, 6 May 2009, Chris Wright wrote: > > There's already locking issues w/ using madvise and ksm, so yes, > changes would need to be made. Some question of how (whether) to handle > registration of unmapped ranges, closest to say ->mm->def_flags=VM_MERGE. > My hunch is there's 2 cases users might care about, a specific range > (qemu-kvm, CERN app, etc) or the entire vma space of a process. Good food for thought there, but not on my mind at this moment. > Another > question of what to do w/ VM_LOCKED, should that exclude VM_MERGE or > let user get what asked for? What's the issue with VM_LOCKED? We wouldn't want to merge a page while it was under get_user_pages (unless KSM's own, but ignore that), but what's the deal with VM_LOCKED? Is the phrase "covert channel" going to come up somehow? Hugh -- 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