From 031bc5743f158b2d5498294f489e534a31251626 Mon Sep 17 00:00:00 2001 From: Joonsoo Kim Date: Fri, 12 Dec 2014 16:55:52 -0800 Subject: [PATCH] mm/debug-pagealloc: make debug-pagealloc boottime configurable Now, we have prepared to avoid using debug-pagealloc in boottime. So introduce new kernel-parameter to disable debug-pagealloc in boottime, and makes related functions to be disabled in this case. Only non-intuitive part is change of guard page functions. Because guard page is effective only if debug-pagealloc is enabled, turning off according to debug-pagealloc is reasonable thing to do. Signed-off-by: Joonsoo Kim Cc: Mel Gorman Cc: Johannes Weiner Cc: Minchan Kim Cc: Dave Hansen Cc: Michal Nazarewicz Cc: Jungsoo Son Cc: Ingo Molnar Cc: Joonsoo Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/kernel-parameters.txt | 9 +++++++++ arch/powerpc/mm/hash_utils_64.c | 2 +- arch/powerpc/mm/pgtable_32.c | 2 +- arch/s390/mm/pageattr.c | 2 +- arch/sparc/mm/init_64.c | 2 +- arch/x86/mm/pageattr.c | 2 +- include/linux/mm.h | 17 ++++++++++++++++- mm/debug-pagealloc.c | 8 +++++++- mm/page_alloc.c | 20 ++++++++++++++++++++ 9 files changed, 57 insertions(+), 7 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 24539d1c7d25..6f067954675b 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -829,6 +829,15 @@ bytes respectively. Such letter suffixes can also be entirely omitted. CONFIG_DEBUG_PAGEALLOC, hence this option will not help tracking down these problems. + debug_pagealloc= + [KNL] When CONFIG_DEBUG_PAGEALLOC is set, this + parameter enables the feature at boot time. In + default, it is disabled. We can avoid allocating huge + chunk of memory for debug pagealloc if we don't enable + it at boot time and the system will work mostly same + with the kernel built without CONFIG_DEBUG_PAGEALLOC. + on: enable the feature + debugpat [X86] Enable PAT debugging decnet.addr= [HW,NET] diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c index e56a307bc676..2c2022d16059 100644 --- a/arch/powerpc/mm/hash_utils_64.c +++ b/arch/powerpc/mm/hash_utils_64.c @@ -1514,7 +1514,7 @@ static void kernel_unmap_linear_page(unsigned long vaddr, unsigned long lmi) mmu_kernel_ssize, 0); } -void kernel_map_pages(struct page *page, int numpages, int enable) +void __kernel_map_pages(struct page *page, int numpages, int enable) { unsigned long flags, vaddr, lmi; int i; diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c index d545b1231594..50fad3801f30 100644 --- a/arch/powerpc/mm/pgtable_32.c +++ b/arch/powerpc/mm/pgtable_32.c @@ -429,7 +429,7 @@ static int change_page_attr(struct page *page, int numpages, pgprot_t prot) } -void kernel_map_pages(struct page *page, int numpages, int enable) +void __kernel_map_pages(struct page *page, int numpages, int enable) { if (PageHighMem(page)) return; diff --git a/arch/s390/mm/pageattr.c b/arch/s390/mm/pageattr.c index 3fef3b299665..426c9d462d1c 100644 --- a/arch/s390/mm/pageattr.c +++ b/arch/s390/mm/pageattr.c @@ -120,7 +120,7 @@ static void ipte_range(pte_t *pte, unsigned long address, int nr) } } -void kernel_map_pages(struct page *page, int numpages, int enable) +void __kernel_map_pages(struct page *page, int numpages, int enable) { unsigned long address; int nr, i, j; diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c index 2d91c62f7f5f..3ea267c53320 100644 --- a/arch/sparc/mm/init_64.c +++ b/arch/sparc/mm/init_64.c @@ -1621,7 +1621,7 @@ static void __init kernel_physical_mapping_init(void) } #ifdef CONFIG_DEBUG_PAGEALLOC -void kernel_map_pages(struct page *page, int numpages, int enable) +void __kernel_map_pages(struct page *page, int numpages, int enable) { unsigned long phys_start = page_to_pfn(page) << PAGE_SHIFT; unsigned long phys_end = phys_start + (numpages * PAGE_SIZE); diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index a3a5d46605d2..dfaf2e0f5f8f 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -1817,7 +1817,7 @@ static int __set_pages_np(struct page *page, int numpages) return __change_page_attr_set_clr(&cpa, 0); } -void kernel_map_pages(struct page *page, int numpages, int enable) +void __kernel_map_pages(struct page *page, int numpages, int enable) { if (PageHighMem(page)) return; diff --git a/include/linux/mm.h b/include/linux/mm.h index 66560f1a0564..8b8d77a1532f 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2061,7 +2061,22 @@ static inline void vm_stat_account(struct mm_struct *mm, #endif /* CONFIG_PROC_FS */ #ifdef CONFIG_DEBUG_PAGEALLOC -extern void kernel_map_pages(struct page *page, int numpages, int enable); +extern bool _debug_pagealloc_enabled; +extern void __kernel_map_pages(struct page *page, int numpages, int enable); + +static inline bool debug_pagealloc_enabled(void) +{ + return _debug_pagealloc_enabled; +} + +static inline void +kernel_map_pages(struct page *page, int numpages, int enable) +{ + if (!debug_pagealloc_enabled()) + return; + + __kernel_map_pages(page, numpages, enable); +} #ifdef CONFIG_HIBERNATION extern bool kernel_page_present(struct page *page); #endif /* CONFIG_HIBERNATION */ diff --git a/mm/debug-pagealloc.c b/mm/debug-pagealloc.c index 0072f2c53331..5bf5906ce13b 100644 --- a/mm/debug-pagealloc.c +++ b/mm/debug-pagealloc.c @@ -10,11 +10,17 @@ static bool page_poisoning_enabled __read_mostly; static bool need_page_poisoning(void) { + if (!debug_pagealloc_enabled()) + return false; + return true; } static void init_page_poisoning(void) { + if (!debug_pagealloc_enabled()) + return; + page_poisoning_enabled = true; } @@ -119,7 +125,7 @@ static void unpoison_pages(struct page *page, int n) unpoison_page(page + i); } -void kernel_map_pages(struct page *page, int numpages, int enable) +void __kernel_map_pages(struct page *page, int numpages, int enable) { if (!page_poisoning_enabled) return; diff --git a/mm/page_alloc.c b/mm/page_alloc.c index e0a39d328ca1..303d38516807 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -425,15 +425,35 @@ static inline void prep_zero_page(struct page *page, unsigned int order, #ifdef CONFIG_DEBUG_PAGEALLOC unsigned int _debug_guardpage_minorder; +bool _debug_pagealloc_enabled __read_mostly; bool _debug_guardpage_enabled __read_mostly; +static int __init early_debug_pagealloc(char *buf) +{ + if (!buf) + return -EINVAL; + + if (strcmp(buf, "on") == 0) + _debug_pagealloc_enabled = true; + + return 0; +} +early_param("debug_pagealloc", early_debug_pagealloc); + static bool need_debug_guardpage(void) { + /* If we don't use debug_pagealloc, we don't need guard page */ + if (!debug_pagealloc_enabled()) + return false; + return true; } static void init_debug_guardpage(void) { + if (!debug_pagealloc_enabled()) + return; + _debug_guardpage_enabled = true; } -- GitLab