mm/debug-pagealloc: prepare boottime configurable on/off

[cascardo/linux.git] / mm / debug-pagealloc.c

diff --git a/mm/debug-pagealloc.c b/mm/debug-pagealloc.c
index 789ff70..0072f2c 100644 (file)
--- a/mm/debug-pagealloc.c
+++ b/mm/debug-pagealloc.c
@@ -2,23 +2,49 @@
 #include <linux/string.h>
 #include <linux/mm.h>
 #include <linux/highmem.h>
-#include <linux/page-debug-flags.h>
+#include <linux/page_ext.h>
 #include <linux/poison.h>
 #include <linux/ratelimit.h>
 
+static bool page_poisoning_enabled __read_mostly;
+
+static bool need_page_poisoning(void)
+{
+       return true;
+}
+
+static void init_page_poisoning(void)
+{
+       page_poisoning_enabled = true;
+}
+
+struct page_ext_operations page_poisoning_ops = {
+       .need = need_page_poisoning,
+       .init = init_page_poisoning,
+};
+
 static inline void set_page_poison(struct page *page)
 {
-       __set_bit(PAGE_DEBUG_FLAG_POISON, &page->debug_flags);
+       struct page_ext *page_ext;
+
+       page_ext = lookup_page_ext(page);
+       __set_bit(PAGE_EXT_DEBUG_POISON, &page_ext->flags);
 }
 
 static inline void clear_page_poison(struct page *page)
 {
-       __clear_bit(PAGE_DEBUG_FLAG_POISON, &page->debug_flags);
+       struct page_ext *page_ext;
+
+       page_ext = lookup_page_ext(page);
+       __clear_bit(PAGE_EXT_DEBUG_POISON, &page_ext->flags);
 }
 
 static inline bool page_poison(struct page *page)
 {
-       return test_bit(PAGE_DEBUG_FLAG_POISON, &page->debug_flags);
+       struct page_ext *page_ext;
+
+       page_ext = lookup_page_ext(page);
+       return test_bit(PAGE_EXT_DEBUG_POISON, &page_ext->flags);
 }
 
 static void poison_page(struct page *page)
@@ -95,6 +121,9 @@ static void unpoison_pages(struct page *page, int n)
 
 void kernel_map_pages(struct page *page, int numpages, int enable)
 {
+       if (!page_poisoning_enabled)
+               return;
+
        if (enable)
                unpoison_pages(page, numpages);
        else