Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755266AbcCWMtE (ORCPT ); Wed, 23 Mar 2016 08:49:04 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:48889 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755147AbcCWMs4 (ORCPT ); Wed, 23 Mar 2016 08:48:56 -0400 From: Vaishali Thakkar 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 Date: Wed, 23 Mar 2016 17:52:08 +0530 Message-Id: <1458735728-15267-1-git-send-email-vaishali.thakkar@oracle.com> X-Mailer: git-send-email 2.1.4 X-Source-IP: aserv0021.oracle.com [141.146.126.233] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3756 Lines: 102 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 --- 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