Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753063AbcCVXiz (ORCPT ); Tue, 22 Mar 2016 19:38:55 -0400 Received: from TYO201.gate.nec.co.jp ([210.143.35.51]:34742 "EHLO tyo201.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750826AbcCVXiv convert rfc822-to-8bit (ORCPT ); Tue, 22 Mar 2016 19:38:51 -0400 From: Naoya Horiguchi To: Vaishali Thakkar CC: "akpm@linux-foundation.org" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , Mike Kravetz , Hillf Danton , "Michal Hocko" , Yaowei Bai , "Dominik Dingel" , "Kirill A. Shutemov" , Paul Gortmaker , Dave Hansen Subject: Re: [PATCH 1/2] mm/hugetlb: Introduce hugetlb_bad_size Thread-Topic: [PATCH 1/2] mm/hugetlb: Introduce hugetlb_bad_size Thread-Index: AQHRhCM07Na6HllOv0uGImbfLJ2vk59liESA Date: Tue, 22 Mar 2016 23:36:52 +0000 Message-ID: <20160322233651.GA24819@hori1.linux.bs1.fc.nec.co.jp> References: <1458640843-13483-1-git-send-email-vaishali.thakkar@oracle.com> In-Reply-To: <1458640843-13483-1-git-send-email-vaishali.thakkar@oracle.com> Accept-Language: ja-JP, en-US Content-Language: ja-JP X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.128.101.8] Content-Type: text/plain; charset="iso-2022-jp" Content-ID: <75FBB824EB65A54C85D7594532551B8C@gisp.nec.co.jp> Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4243 Lines: 109 On Tue, Mar 22, 2016 at 03:30:43PM +0530, Vaishali Thakkar wrote: > When any unsupported hugepage size is specified, 'hugepagesz=' and > 'hugepages=' should be ignored during command line parsing until any > supported hugepage size is found. But currently incorrect number of > hugepages are allocated when unsupported size is specified as it fails > to ignore the 'hugepages=' command. > > Test case: > > Note that this is specific to x86 architecture. > > Boot the kernel with command line option 'hugepagesz=256M hugepages=X'. > After boot, dmesg output shows that X number of hugepages of the size 2M > is pre-allocated instead of 0. > > So, to handle such command line options, introduce new routine > hugetlb_bad_size. The routine hugetlb_bad_size sets the global variable > parsed_valid_hugepagesz. We are using parsed_valid_hugepagesz to save the > state when unsupported hugepagesize is found so that we can ignore the > 'hugepages=' parameters after that and then reset the variable when > supported hugepage size is found. > > The routine hugetlb_bad_size can be called while setting 'hugepagesz=' > parameter in an architecture specific code. > Signed-off-by: Vaishali Thakkar > Cc: Mike Kravetz > Cc: Naoya Horiguchi > Cc: Hillf Danton > Cc: Michal Hocko > Cc: Yaowei Bai > Cc: Dominik Dingel > Cc: Kirill A. Shutemov > Cc: Paul Gortmaker > Cc: Dave Hansen Maybe parsed_hstate can do what parsed_valid_hugepagesz does, but both are __initdata so it's not a big deal. Reviewed-by: Naoya Horiguchi > --- > The patch is having 2 checkpatch.pl warnings. I have just followed > the current code to maintain consistency. If we decide to silent > these warnings then may be we should silent those warnings as well. > I am fine with any option whichever works best for everyone else. > --- > include/linux/hugetlb.h | 1 + > mm/hugetlb.c | 14 +++++++++++++- > 2 files changed, 14 insertions(+), 1 deletion(-) > > diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h > index 7d953c2..e44c578 100644 > --- a/include/linux/hugetlb.h > +++ b/include/linux/hugetlb.h > @@ -338,6 +338,7 @@ int huge_add_to_page_cache(struct page *page, struct address_space *mapping, > /* arch callback */ > int __init alloc_bootmem_huge_page(struct hstate *h); > > +void __init hugetlb_bad_size(void); > void __init hugetlb_add_hstate(unsigned order); > struct hstate *size_to_hstate(unsigned long size); > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index 06058ea..44fae6a 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -51,6 +51,7 @@ __initdata LIST_HEAD(huge_boot_pages); > static struct hstate * __initdata parsed_hstate; > static unsigned long __initdata default_hstate_max_huge_pages; > static unsigned long __initdata default_hstate_size; > +static bool __initdata parsed_valid_hugepagesz = true; > > /* > * Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages, > @@ -2659,6 +2660,11 @@ static int __init hugetlb_init(void) > subsys_initcall(hugetlb_init); > > /* Should be called on processing a hugepagesz=... option */ > +void __init hugetlb_bad_size(void) > +{ > + parsed_valid_hugepagesz = false; > +} > + > void __init hugetlb_add_hstate(unsigned int order) > { > struct hstate *h; > @@ -2691,11 +2697,17 @@ static int __init hugetlb_nrpages_setup(char *s) > unsigned long *mhp; > static unsigned long *last_mhp; > > + if (!parsed_valid_hugepagesz) { > + pr_warn("hugepages = %s preceded by " > + "an unsupported hugepagesz, ignoring\n", s); > + parsed_valid_hugepagesz = true; > + return 1; > + } > /* > * !hugetlb_max_hstate means we haven't parsed a hugepagesz= parameter yet, > * so this hugepages= parameter goes to the "default hstate". > */ > - if (!hugetlb_max_hstate) > + else if (!hugetlb_max_hstate) > mhp = &default_hstate_max_huge_pages; > else > mhp = &parsed_hstate->max_huge_pages; > -- > 2.1.4 >