From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4561E0FA.4040508@oracle.com> Date: Mon, 20 Nov 2006 09:08:10 -0800 From: Randy Dunlap MIME-Version: 1.0 Subject: Re: build error: sparsemem + SLOB References: <20061119210545.9708e366.randy.dunlap@oracle.com> In-Reply-To: Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: linux-mm@kvack.org, mpm@selenic.com, Pekka Enberg List-ID: Christoph Lameter wrote: > On Sun, 19 Nov 2006, Randy Dunlap wrote: > >> mm/sparse.c: line 35 uses slab_is_available() but SLAB=n, SLOB=y. > > I wonder if its worth bothering about SLOB? It's OK with me to make some combination of SLOB and SPARSEMEM an invalid config, as long as that is implemented in Kconfig. > As far as I can tell SLOB is fundamentally racy since it does not support > SLAB_DESTROY_BY_RCU correctly. F.e. The constructor for the anon_vma will > be called on alloc without regard for RCU, we free an item and reuse it > without regard to RCU. This can potentially mess up the anon_vma locking > state while we access it. > > Is SLOB used at all or have we been lucky so far? -- ~Randy -- 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