Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754837AbcCXDK0 (ORCPT ); Wed, 23 Mar 2016 23:10:26 -0400 Received: from out114-136.biz.mail.alibaba.com ([205.204.114.136]:55380 "EHLO out21.biz.mail.alibaba.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753656AbcCXDKZ (ORCPT ); Wed, 23 Mar 2016 23:10:25 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R181e4;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e02c03310;MF=hillf.zj@alibaba-inc.com;NM=1;PH=DS;RN=10;SR=0;TI=SMTPD_----4dZFUwp_1458788964; Reply-To: "Hillf Danton" From: "Hillf Danton" To: "'Vaishali Thakkar'" , Cc: , , "'Michal Hocko'" , "'Yaowei Bai'" , "'Dominik Dingel'" , "'Kirill A. Shutemov'" , "'Paul Gortmaker'" , "'Dave Hansen'" References: <1458735728-15267-1-git-send-email-vaishali.thakkar@oracle.com> In-Reply-To: <1458735728-15267-1-git-send-email-vaishali.thakkar@oracle.com> Subject: Re: [PATCH v2 1/6] mm/hugetlb: Introduce hugetlb_bad_size Date: Thu, 24 Mar 2016 11:09:24 +0800 Message-ID: <0b8001d1857a$9201a260$b604e720$@alibaba-inc.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Outlook 14.0 Thread-Index: AQGn8ZhqQBiIXPx2kbdqQAmTLtMXQ5+7ET4g Content-Language: zh-cn Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4423 Lines: 118 > -----Original Message----- > From: Vaishali Thakkar [mailto:vaishali.thakkar@oracle.com] > Sent: Wednesday, March 23, 2016 8:22 PM > To: akpm@linux-foundation.org > Cc: linux-mm@kvack.org; linux-kernel@vger.kernel.org; Vaishali Thakkar; Hillf Danton; Michal Hocko; Yaowei Bai; Dominik Dingel; Kirill > A. Shutemov; Paul Gortmaker; Dave Hansen > Subject: [PATCH v2 1/6] mm/hugetlb: Introduce hugetlb_bad_size > > 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 > Reviewed-by: Mike Kravetz > Reviewed-by: Naoya Horiguchi > Cc: Hillf Danton > Cc: Michal Hocko > Cc: Yaowei Bai > Cc: Dominik Dingel > Cc: Kirill A. Shutemov > Cc: Paul Gortmaker > Cc: Dave Hansen > --- Acked-by: Hillf Danton > The patch is having 2 checkpatch.pl warnings. I have just followed > the current code to maintain consistency. > Changes since v1: > - Nothing in this patch, just separated changes done in second > patch > --- > 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..5ebdd869 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