From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 31 Aug 2005 14:42:38 +0100 (BST) From: Hugh Dickins Subject: Re: [PATCH 1/1] Implement shared page tables In-Reply-To: <1125489077.3213.12.camel@laptopd505.fenrus.org> Message-ID: References: <7C49DFF721CB4E671DB260F9@[10.1.1.4]> <1125489077.3213.12.camel@laptopd505.fenrus.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Arjan van de Ven Cc: Dave McCracken , Andrew Morton , Linux Kernel , Linux Memory Management List-ID: On Wed, 31 Aug 2005, Arjan van de Ven wrote: > On Wed, 2005-08-31 at 12:44 +0100, Hugh Dickins wrote: > > I was going to say, doesn't randomize_va_space take away the rest of > > the point? But no, it appears "randomize_va_space", as it currently > > appears in mainline anyway, is somewhat an exaggeration: it just shifts > > the stack a little, with no effect on the rest of the va space. > > it also randomizes mmaps Ah, via PF_RANDOMIZE, yes, thanks: so long as certain conditions are fulfilled - and my RLIM_INFINITY RLIMIT_STACK has been preventing it. And mmaps include shmats: so unless the process specifies non-NULL shmaddr to attach at, it'll choose a randomized address for that too (subject to those various conditions). Which is indeed a further disincentive against shared page tables. 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