From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932994Ab2JWKLt (ORCPT ); Tue, 23 Oct 2012 06:11:49 -0400 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:56513 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932948Ab2JWKLq (ORCPT ); Tue, 23 Oct 2012 06:11:46 -0400 Date: Tue, 23 Oct 2012 11:11:25 +0100 From: Will Deacon To: Andrew Morton Cc: David Miller , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "linux-arch@vger.kernel.org" , "mhocko@suse.cz" , "kirill@shutemov.name" , "aarcange@redhat.com" , "cmetcalf@tilera.com" , Steve Capper Subject: Re: [PATCH v2] mm: thp: Set the accessed flag for old pages on access fault. Message-ID: <20121023101125.GA20210@mudshark.cambridge.arm.com> References: <1349197151-19645-1-git-send-email-will.deacon@arm.com> <20121002150104.da57fa94.akpm@linux-foundation.org> <20121017130125.GH5973@mudshark.cambridge.arm.com> <20121017.112620.1865348978594874782.davem@davemloft.net> <20121017155401.GJ5973@mudshark.cambridge.arm.com> <20121018150502.3dee7899.akpm@linux-foundation.org> <20121019091016.GA4582@mudshark.cambridge.arm.com> <20121019114955.3a0c2b66.akpm@linux-foundation.org> <20121022103503.GA26619@mudshark.cambridge.arm.com> <20121022111843.4406850d.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20121022111843.4406850d.akpm@linux-foundation.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 22, 2012 at 07:18:43PM +0100, Andrew Morton wrote: > On Mon, 22 Oct 2012 11:35:03 +0100 > Will Deacon wrote: > > > On Fri, Oct 19, 2012 at 07:49:55PM +0100, Andrew Morton wrote: > > > Ho hum. I'll drop > > > mm-thp-set-the-accessed-flag-for-old-pages-on-access-fault.patch and > > > shall assume that you'll sort things out at the appropriate time. > > > > Happy to sort it out once I work out what's going wrong! > > The patch "ARM: mm: Transparent huge page support for LPAE systems" is > not present in linux-next, so this patch ("mm: thp: Set the accessed > flag for old pages on access fault") will not compile? This patch ("mm: thp: Set the accessed flag for old pages on access fault") doesn't depend on "ARM: mm: Transparent huge page support for LPAE systems" because currently transparent huge pages cannot be enabled for ARM in mainline (or linux-next). update_mmu_cache_pmd is only called from mm/huge_memory.c, which depends on CONFIG_TRANSPARENT_HUGEPAGE=y. As for the new huge_pmd_set_accessed function... there's a similar situation for the do_huge_pmd_wp_page function: it's called from mm/memory.c but is only defined in mm/huge_memory.c. Looks like the compiler optimises those calls away because pmd_trans_huge and friends constant-fold to 0. Will