From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx102.postini.com [74.125.245.102]) by kanga.kvack.org (Postfix) with SMTP id C252A6B0062 for ; Mon, 22 Oct 2012 06:35:13 -0400 (EDT) Date: Mon, 22 Oct 2012 11:35:03 +0100 From: Will Deacon Subject: Re: [PATCH v2] mm: thp: Set the accessed flag for old pages on access fault. Message-ID: <20121022103503.GA26619@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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20121019114955.3a0c2b66.akpm@linux-foundation.org> Sender: owner-linux-mm@kvack.org List-ID: 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 On Fri, Oct 19, 2012 at 07:49:55PM +0100, Andrew Morton wrote: > On Fri, 19 Oct 2012 10:10:16 +0100 > Will Deacon wrote: > > > On Thu, Oct 18, 2012 at 11:05:02PM +0100, Andrew Morton wrote: > > > On Wed, 17 Oct 2012 16:54:02 +0100 > > > Will Deacon wrote: > > > > > > > On x86 memory accesses to pages without the ACCESSED flag set result in the > > > > ACCESSED flag being set automatically. With the ARM architecture a page access > > > > fault is raised instead (and it will continue to be raised until the ACCESSED > > > > flag is set for the appropriate PTE/PMD). > > > > > > > > For normal memory pages, handle_pte_fault will call pte_mkyoung (effectively > > > > setting the ACCESSED flag). For transparent huge pages, pmd_mkyoung will only > > > > be called for a write fault. > > > > > > > > This patch ensures that faults on transparent hugepages which do not result > > > > in a CoW update the access flags for the faulting pmd. > > > > > > Confused. Where is the arm implementation of update_mmu_cache_pmd()? > > > > Right at the end of this patch, which was posted to the ARM list yesterday: > > > > http://lists.infradead.org/pipermail/linux-arm-kernel/2012-October/126387.html > > I received and then merged a patch which won't compile! Eek, that certainly wasn't intentional and it's compiling fine for me on -rc1 and -rc2 for both ARM (no THP) and x86 (with and without THP). Please can you send the build failure? > 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! Cheers, Will -- 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