From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: [PATCH v2] mm: thp: Set the accessed flag for old pages on access fault. Date: Tue, 23 Oct 2012 14:50:27 -0700 Message-ID: <20121023145027.40710e7a.akpm@linux-foundation.org> 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> <20121023101125.GA20210@mudshark.cambridge.arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from mail.linuxfoundation.org ([140.211.169.12]:56928 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754816Ab2JWVu2 (ORCPT ); Tue, 23 Oct 2012 17:50:28 -0400 In-Reply-To: <20121023101125.GA20210@mudshark.cambridge.arm.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Will Deacon 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 Tue, 23 Oct 2012 11:11:25 +0100 Will Deacon wrote: > 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. Ah, OK. "mm: thp: Set the accessed flag for old pages on access fault" clashes in a non-trivial way with linux-next changes, due to the sched-numa changes (sigh). This is a problem for me, because I either need to significantly alter your patch (so it isn't applicable to mainline) or I need to stage your patch ahead of linux-next, then fix up linux-next every day after I've pulled and re-merged it. I'm unsure what your timing is. Can you carry "mm: thp: Set the accessed flag for old pages on access fault" until either the whole patchset is ready to merge or until the sched-numa situation has been cleared up?