Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751924Ab2E2NQp (ORCPT ); Tue, 29 May 2012 09:16:45 -0400 Received: from casper.infradead.org ([85.118.1.10]:55507 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751369Ab2E2NQo convert rfc822-to-8bit (ORCPT ); Tue, 29 May 2012 09:16:44 -0400 Message-ID: <1338297385.26856.74.camel@twins> Subject: Re: [PATCH 13/35] autonuma: add page structure fields From: Peter Zijlstra To: Andrea Arcangeli Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Hillf Danton , Dan Smith , Linus Torvalds , Andrew Morton , Thomas Gleixner , Ingo Molnar , Paul Turner , Suresh Siddha , Mike Galbraith , "Paul E. McKenney" , Lai Jiangshan , Bharata B Rao , Lee Schermerhorn , Rik van Riel , Johannes Weiner , Srivatsa Vaddagiri , Christoph Lameter Date: Tue, 29 May 2012 15:16:25 +0200 In-Reply-To: <1337965359-29725-14-git-send-email-aarcange@redhat.com> References: <1337965359-29725-1-git-send-email-aarcange@redhat.com> <1337965359-29725-14-git-send-email-aarcange@redhat.com> Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Mailer: Evolution 3.2.2- Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1797 Lines: 54 On Fri, 2012-05-25 at 19:02 +0200, Andrea Arcangeli wrote: > diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h > index 780ded7..e8dc82c 100644 > --- a/include/linux/mm_types.h > +++ b/include/linux/mm_types.h > @@ -126,6 +126,31 @@ struct page { > struct page *first_page; /* Compound tail pages */ > }; > > +#ifdef CONFIG_AUTONUMA > + /* > + * FIXME: move to pgdat section along with the memcg and allocate > + * at runtime only in presence of a numa system. > + */ > + /* > + * To modify autonuma_last_nid lockless the architecture, > + * needs SMP atomic granularity < sizeof(long), not all archs > + * have that, notably some alpha. Archs without that requires > + * autonuma_last_nid to be a long. > + */ > +#if BITS_PER_LONG > 32 > + int autonuma_migrate_nid; > + int autonuma_last_nid; > +#else > +#if MAX_NUMNODES >= 32768 > +#error "too many nodes" > +#endif > + /* FIXME: remember to check the updates are atomic */ > + short autonuma_migrate_nid; > + short autonuma_last_nid; > +#endif > + struct list_head autonuma_migrate_node; > +#endif > + > /* > * On machines where all RAM is mapped into kernel address space, > * we can simply calculate the virtual address. On machines with 24 bytes per page.. or ~0.6% of memory gone. This is far too great a price to pay. At LSF/MM Rik already suggested you limit the number of pages that can be migrated concurrently and use this to move the extra list_head out of struct page and into a smaller amount of extra structures, reducing the total overhead. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/