From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f197.google.com (mail-qk0-f197.google.com [209.85.220.197]) by kanga.kvack.org (Postfix) with ESMTP id 0578C831F5 for ; Thu, 18 May 2017 04:50:35 -0400 (EDT) Received: by mail-qk0-f197.google.com with SMTP id z142so13846495qkz.8 for ; Thu, 18 May 2017 01:50:35 -0700 (PDT) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com. [148.163.158.5]) by mx.google.com with ESMTPS id m31si4925409qta.239.2017.05.18.01.50.34 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 18 May 2017 01:50:34 -0700 (PDT) Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v4I8cYRK127740 for ; Thu, 18 May 2017 04:50:33 -0400 Received: from e14.ny.us.ibm.com (e14.ny.us.ibm.com [129.33.205.204]) by mx0b-001b2d01.pphosted.com with ESMTP id 2ah3c5bvpx-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Thu, 18 May 2017 04:50:33 -0400 Received: from localhost by e14.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 18 May 2017 04:50:32 -0400 Subject: Re: [PATCH v3 2/2] powerpc/mm/hugetlb: Add support for 1G huge pages References: <1494995292-4443-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1494995292-4443-2-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <87fug2loze.fsf@concordia.ellerman.id.au> <852b601c-a044-0445-e97d-d17d76ec1154@linux.vnet.ibm.com> <877f1elfga.fsf@concordia.ellerman.id.au> From: "Aneesh Kumar K.V" Date: Thu, 18 May 2017 14:20:24 +0530 MIME-Version: 1.0 In-Reply-To: <877f1elfga.fsf@concordia.ellerman.id.au> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Message-Id: Sender: owner-linux-mm@kvack.org List-ID: To: Michael Ellerman , akpm@linux-foundation.org, Anshuman Khandual Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org On Thursday 18 May 2017 02:17 PM, Michael Ellerman wrote: > "Aneesh Kumar K.V" writes: > >> On Thursday 18 May 2017 10:51 AM, Michael Ellerman wrote: >>> "Aneesh Kumar K.V" writes: >>> >>>> POWER9 supports hugepages of size 2M and 1G in radix MMU mode. This patch >>>> enables the usage of 1G page size for hugetlbfs. This also update the helper >>>> such we can do 1G page allocation at runtime. >>>> >>>> We still don't enable 1G page size on DD1 version. This is to avoid doing >>>> workaround mentioned in commit: 6d3a0379ebdc8 (powerpc/mm: Add >>>> radix__tlb_flush_pte_p9_dd1() >>>> >>>> Signed-off-by: Aneesh Kumar K.V >>>> --- >>>> arch/powerpc/include/asm/book3s/64/hugetlb.h | 10 ++++++++++ >>>> arch/powerpc/mm/hugetlbpage.c | 7 +++++-- >>>> arch/powerpc/platforms/Kconfig.cputype | 1 + >>>> 3 files changed, 16 insertions(+), 2 deletions(-) >>> >>> I think this patch is OK, but it's very confusing because it doesn't >>> mention that it's only talking about *generic* gigantic page support. >> >> What you mean by generic gigantic page ? what is supported here is the >> gigantic page with size 1G alone ? > > What about 16G pages on pseries. > > And all the other gigantic page sizes that Book3E supports? > None of that is supported w.r.t runtime allocation of hugepages. ie, we cannot echo nr_hugepages w.r.t them. For 16GB i am not sure it make sense, because we will rarely get such large contiguous region. W.r.t page size supported for Book3E, may be we can. But I don't have a facility to test those. Hence didn't include that. -aneesh -- 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