From 031bc5743f158b2d5498294f489e534a31251626 Mon Sep 17 00:00:00 2001 From: Joonsoo Kim Date: Fri, 12 Dec 2014 16:55:52 -0800 Subject: 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 --- mm/page_alloc.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'mm/page_alloc.c') 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; } -- cgit v1.2.3