Date: Tue, 30 Oct 2018 14:35:57 -0700 From: Matthew Wilcox <willy@...radead.org> To: Igor Stoppa <igor.stoppa@...il.com> Cc: Tycho Andersen <tycho@...ho.ws>, Andy Lutomirski <luto@...capital.net>, Kees Cook <keescook@...omium.org>, Peter Zijlstra <peterz@...radead.org>, Mimi Zohar <zohar@...ux.vnet.ibm.com>, Dave Chinner <david@...morbit.com>, James Morris <jmorris@...ei.org>, Michal Hocko <mhocko@...nel.org>, Kernel Hardening <kernel-hardening@...ts.openwall.com>, linux-integrity <linux-integrity@...r.kernel.org>, linux-security-module <linux-security-module@...r.kernel.org>, Igor Stoppa <igor.stoppa@...wei.com>, Dave Hansen <dave.hansen@...ux.intel.com>, Jonathan Corbet <corbet@....net>, Laura Abbott <labbott@...hat.com>, Randy Dunlap <rdunlap@...radead.org>, Mike Rapoport <rppt@...ux.vnet.ibm.com>, "open list:DOCUMENTATION" <linux-doc@...r.kernel.org>, LKML <linux-kernel@...r.kernel.org>, Thomas Gleixner <tglx@...utronix.de> Subject: Re: [PATCH 10/17] prmem: documentation On Tue, Oct 30, 2018 at 10:43:14PM +0200, Igor Stoppa wrote: > On 30/10/2018 21:20, Matthew Wilcox wrote: > > > > So the API might look something like this: > > > > > > > > void *p = rare_alloc(...); /* writable pointer */ > > > > p->a = x; > > > > q = rare_protect(p); /* read-only pointer */ > > With pools and memory allocated from vmap_areas, I was able to say > > protect(pool) > > and that would do a swipe on all the pages currently in use. > In the SELinux policyDB, for example, one doesn't really want to > individually protect each allocation. > > The loading phase happens usually at boot, when the system can be assumed to > be sane (one might even preload a bare-bone set of rules from initramfs and > then replace it later on, with the full blown set). > > There is no need to process each of these tens of thousands allocations and > initialization as write-rare. > > Would it be possible to do the same here? What Andy is proposing effectively puts all rare allocations into one pool. Although I suppose it could be generalised to multiple pools ... one mm_struct per pool. Andy, what do you think to doing that? > > but we'd probably wrap it in list_for_each_rare_entry(), just to be nicer. > > This seems suspiciously close to the duplication of kernel interfaces that I > was roasted for :-) Can you not see the difference between adding one syntactic sugar function and duplicating the entire infrastructure?
Powered by blists - more mailing lists
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.