From 9fee021d15ddd884d40d1540913474e8112313fe Mon Sep 17 00:00:00 2001 From: Vaishali Thakkar Date: Thu, 19 May 2016 17:11:04 -0700 Subject: [PATCH] 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 Acked-by: Michal Hocko Cc: Hillf Danton Cc: Yaowei Bai Cc: Dominik Dingel Cc: Kirill A. Shutemov Cc: Paul Gortmaker Cc: Dave Hansen Cc: Benjamin Herrenschmidt Cc: James Hogan Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "H. Peter Anvin" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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 7d953c2542a8..e44c57876e89 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 fb37ef810655..0adb74d0a4e1 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; -- 2.20.1