From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by ozlabs.org (Postfix) with ESMTP id 146092C0082 for ; Fri, 6 Dec 2013 04:28:38 +1100 (EST) Message-ID: <52A0B786.608@redhat.com> Date: Thu, 05 Dec 2013 12:27:34 -0500 From: Rik van Riel MIME-Version: 1.0 To: Benjamin Herrenschmidt , "Aneesh Kumar K.V" Subject: Re: [PATCH -V2 3/5] mm: Move change_prot_numa outside CONFIG_ARCH_USES_NUMA_PROT_NONE References: <1384766893-10189-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1384766893-10189-4-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1386126782.16703.137.camel@pasglop> In-Reply-To: <1386126782.16703.137.camel@pasglop> Content-Type: text/plain; charset=UTF-8; format=flowed Cc: linux-mm@kvack.org, paulus@samba.org, linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 12/03/2013 10:13 PM, Benjamin Herrenschmidt wrote: > On Mon, 2013-11-18 at 14:58 +0530, Aneesh Kumar K.V wrote: >> From: "Aneesh Kumar K.V" >> >> change_prot_numa should work even if _PAGE_NUMA != _PAGE_PROTNONE. >> On archs like ppc64 that don't use _PAGE_PROTNONE and also have >> a separate page table outside linux pagetable, we just need to >> make sure that when calling change_prot_numa we flush the >> hardware page table entry so that next page access result in a numa >> fault. > > That patch doesn't look right... At first glance, indeed... > You are essentially making change_prot_numa() do whatever it does (which > I don't completely understand) *for all architectures* now, whether they > have CONFIG_ARCH_USES_NUMA_PROT_NONE or not ... So because you want that > behaviour on powerpc book3s64, you change everybody. However, it appears that since the code was #ifdefed like that, the called code was made generic enough, that change_prot_numa should actually work for everything. In other words: Reviewed-by: Rik van Riel