From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with SMTP id 9E6B66B003D for ; Thu, 2 Apr 2009 10:40:53 -0400 (EDT) Date: Thu, 2 Apr 2009 16:41:18 +0200 From: Andrea Arcangeli Subject: Re: [PATCH 5/4] update ksm userspace interfaces Message-ID: <20090402144118.GH9137@random.random> References: <49D22A9D.4050403@codemonkey.ws> <20090331150218.GS9137@random.random> <49D23224.9000903@codemonkey.ws> <20090331151845.GT9137@random.random> <49D23CD1.9090208@codemonkey.ws> <20090331162525.GU9137@random.random> <49D24A02.6070000@codemonkey.ws> <20090402012215.GE1117@x200.localdomain> <49D424AF.3090806@codemonkey.ws> <20090402053114.GF1117@x200.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090402053114.GF1117@x200.localdomain> Sender: owner-linux-mm@kvack.org To: Chris Wright Cc: Anthony Liguori , Izik Eidus , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org, avi@redhat.com, riel@redhat.com, jeremy@goop.org, mtosatti@redhat.com, hugh@veritas.com, corbet@lwn.net, yaniv@redhat.com, dmonakhov@openvz.org List-ID: On Wed, Apr 01, 2009 at 10:31:14PM -0700, Chris Wright wrote: > - register only ATM, can add MADV_UNSHAREABLE to allow an app to proactively > unregister, but need a cleanup when ->mm goes away via exit/exec The unregister cleanup must happen at the vma level (with unregister when vma goes away or is overwritten) for this to provide sane madvise semantics (not just in exit/exec, but in unmap/mmap too). Otherwise this is all but madvise. Basically we need a chunk of code in core VM when KSM=y/m, even if we keep returning -EINVAL when KSM=n (for backwards compatibility, -ENOSYS not). Example, vma must be split in two if you MAP_SHARABLE only part of it 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