mm,x86: remove debug_pagealloc_enabled

When (no)bootmem finishes its operation, it passes pages to the buddy
allocator.  Since debug_pagealloc_enabled is not set, we will not protect
these pages, which is not what we want with CONFIG_DEBUG_PAGEALLOC=y.

To fix this, remove debug_pagealloc_enabled.  That variable was introduced
by commit 12d6f21e ("x86: do not PSE on CONFIG_DEBUG_PAGEALLOC=y") to get
more CPA (change page attribude) code testing.  But currently we have
CONFIG_CPA_DEBUG, which tests CPA.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index eda2acbb6e81b2895e7645bd21fc8624ad355e7e..e1ebde3152104840961fe6e953b28d628f4bab82 100644 (file)
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -1333,12 +1333,6 @@ void kernel_map_pages(struct page *page, int numpages, int enable)
                                           numpages * PAGE_SIZE);
        }
 
-       /*
-        * If page allocator is not up yet then do not call c_p_a():
-        */
-       if (!debug_pagealloc_enabled)
-               return;
-
        /*
         * The return value is ignored as the calls cannot fail.
         * Large pages for identity mappings are not used at boot time

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 01f614b2fbc77bc4e503208e77a45e071052e5a0..243a736ab30fdebc517751b2af3787d4d518a868 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1538,23 +1538,13 @@ static inline void vm_stat_account(struct mm_struct *mm,
 #endif /* CONFIG_PROC_FS */
 
 #ifdef CONFIG_DEBUG_PAGEALLOC
-extern int debug_pagealloc_enabled;
-
 extern void kernel_map_pages(struct page *page, int numpages, int enable);
-
-static inline void enable_debug_pagealloc(void)
-{
-       debug_pagealloc_enabled = 1;
-}
 #ifdef CONFIG_HIBERNATION
 extern bool kernel_page_present(struct page *page);
 #endif /* CONFIG_HIBERNATION */
 #else
 static inline void
 kernel_map_pages(struct page *page, int numpages, int enable) {}
-static inline void enable_debug_pagealloc(void)
-{
-}
 #ifdef CONFIG_HIBERNATION
 static inline bool kernel_page_present(struct page *page) { return true; }
 #endif /* CONFIG_HIBERNATION */

diff --git a/init/main.c b/init/main.c
index 217ed23e94875d59ffd7b6a95562fcba36112e08..99c4ba30ba7e46a6c71b3e74ad8fcc59679bd8d7 100644 (file)
--- a/init/main.c
+++ b/init/main.c
@@ -282,10 +282,6 @@ static int __init unknown_bootoption(char *param, char *val)
        return 0;
 }
 
-#ifdef CONFIG_DEBUG_PAGEALLOC
-int __read_mostly debug_pagealloc_enabled = 0;
-#endif
-
 static int __init init_setup(char *str)
 {
        unsigned int i;
@@ -597,7 +593,6 @@ asmlinkage void __init start_kernel(void)
        }
 #endif
        page_cgroup_init();
-       enable_debug_pagealloc();
        debug_objects_mem_init();
        kmemleak_init();
        setup_per_cpu_pageset();

diff --git a/mm/debug-pagealloc.c b/mm/debug-pagealloc.c
index 7cea557407f40ef96351a91ade5fd3b9cbe915c0..789ff70c8a4ab7f84bb81410d3e3982a7cb3f987 100644 (file)
--- a/mm/debug-pagealloc.c
+++ b/mm/debug-pagealloc.c
@@ -95,9 +95,6 @@ static void unpoison_pages(struct page *page, int n)
 
 void kernel_map_pages(struct page *page, int numpages, int enable)
 {
-       if (!debug_pagealloc_enabled)
-               return;
-
        if (enable)
                unpoison_pages(page, numpages);
        else