mm: page_alloc: split out DEBUG_PAGEALLOC

Move DEBUG_PAGEALLOC related functions into a single file to reduce a bit
of page_alloc.c.

Link: https://lkml.kernel.org/r/20230516063821.121844-9-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/mm.h b/include/linux/mm.h
index f64bfbd53c65af6c796f5271c8658d11140799de..2382eaf6fd811d26e8d0e76a0478fcc945ab0470 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3471,9 +3471,58 @@ static inline void debug_pagealloc_unmap_pages(struct page *page, int numpages)
        if (debug_pagealloc_enabled_static())
                __kernel_map_pages(page, numpages, 0);
 }
+
+extern unsigned int _debug_guardpage_minorder;
+DECLARE_STATIC_KEY_FALSE(_debug_guardpage_enabled);
+
+static inline unsigned int debug_guardpage_minorder(void)
+{
+       return _debug_guardpage_minorder;
+}
+
+static inline bool debug_guardpage_enabled(void)
+{
+       return static_branch_unlikely(&_debug_guardpage_enabled);
+}
+
+static inline bool page_is_guard(struct page *page)
+{
+       if (!debug_guardpage_enabled())
+               return false;
+
+       return PageGuard(page);
+}
+
+bool __set_page_guard(struct zone *zone, struct page *page, unsigned int order,
+                     int migratetype);
+static inline bool set_page_guard(struct zone *zone, struct page *page,
+                                 unsigned int order, int migratetype)
+{
+       if (!debug_guardpage_enabled())
+               return false;
+       return __set_page_guard(zone, page, order, migratetype);
+}
+
+void __clear_page_guard(struct zone *zone, struct page *page, unsigned int order,
+                       int migratetype);
+static inline void clear_page_guard(struct zone *zone, struct page *page,
+                                   unsigned int order, int migratetype)
+{
+       if (!debug_guardpage_enabled())
+               return;
+       __clear_page_guard(zone, page, order, migratetype);
+}
+
 #else  /* CONFIG_DEBUG_PAGEALLOC */
 static inline void debug_pagealloc_map_pages(struct page *page, int numpages) {}
 static inline void debug_pagealloc_unmap_pages(struct page *page, int numpages) {}
+static inline unsigned int debug_guardpage_minorder(void) { return 0; }
+static inline bool debug_guardpage_enabled(void) { return false; }
+static inline bool page_is_guard(struct page *page) { return false; }
+static inline bool set_page_guard(struct zone *zone, struct page *page,
+                       unsigned int order, int migratetype) { return false; }
+static inline void clear_page_guard(struct zone *zone, struct page *page,
+                               unsigned int order, int migratetype) {}
 #endif /* CONFIG_DEBUG_PAGEALLOC */
 
 #ifdef __HAVE_ARCH_GATE_AREA
@@ -3711,33 +3760,6 @@ static inline bool vma_is_special_huge(const struct vm_area_struct *vma)
 
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */
 
-#ifdef CONFIG_DEBUG_PAGEALLOC
-extern unsigned int _debug_guardpage_minorder;
-DECLARE_STATIC_KEY_FALSE(_debug_guardpage_enabled);
-
-static inline unsigned int debug_guardpage_minorder(void)
-{
-       return _debug_guardpage_minorder;
-}
-
-static inline bool debug_guardpage_enabled(void)
-{
-       return static_branch_unlikely(&_debug_guardpage_enabled);
-}
-
-static inline bool page_is_guard(struct page *page)
-{
-       if (!debug_guardpage_enabled())
-               return false;
-
-       return PageGuard(page);
-}
-#else
-static inline unsigned int debug_guardpage_minorder(void) { return 0; }
-static inline bool debug_guardpage_enabled(void) { return false; }
-static inline bool page_is_guard(struct page *page) { return false; }
-#endif /* CONFIG_DEBUG_PAGEALLOC */
-
 #if MAX_NUMNODES > 1
 void __init setup_nr_node_ids(void);
 #else

diff --git a/mm/Makefile b/mm/Makefile
index 0eec4bc72d3f780f7fae7056ae6674fe31fca8f1..678530a073261f1af59384b857eb915ee2029cfa 100644 (file)
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -124,6 +124,7 @@ obj-$(CONFIG_SECRETMEM) += secretmem.o
 obj-$(CONFIG_CMA_SYSFS) += cma_sysfs.o
 obj-$(CONFIG_USERFAULTFD) += userfaultfd.o
 obj-$(CONFIG_IDLE_PAGE_TRACKING) += page_idle.o
+obj-$(CONFIG_DEBUG_PAGEALLOC) += debug_page_alloc.o
 obj-$(CONFIG_DEBUG_PAGE_REF) += debug_page_ref.o
 obj-$(CONFIG_DAMON) += damon/
 obj-$(CONFIG_HARDENED_USERCOPY) += usercopy.o

diff --git a/mm/debug_page_alloc.c b/mm/debug_page_alloc.c
new file mode 100644 (file)
index 0000000..f9d1457
--- /dev/null
+++ b/mm/debug_page_alloc.c
@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/mm.h>
+#include <linux/page-isolation.h>
+
+unsigned int _debug_guardpage_minorder;
+
+bool _debug_pagealloc_enabled_early __read_mostly
+                       = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT);
+EXPORT_SYMBOL(_debug_pagealloc_enabled_early);
+DEFINE_STATIC_KEY_FALSE(_debug_pagealloc_enabled);
+EXPORT_SYMBOL(_debug_pagealloc_enabled);
+
+DEFINE_STATIC_KEY_FALSE(_debug_guardpage_enabled);
+
+static int __init early_debug_pagealloc(char *buf)
+{
+       return kstrtobool(buf, &_debug_pagealloc_enabled_early);
+}
+early_param("debug_pagealloc", early_debug_pagealloc);
+
+static int __init debug_guardpage_minorder_setup(char *buf)
+{
+       unsigned long res;
+
+       if (kstrtoul(buf, 10, &res) < 0 ||  res > MAX_ORDER / 2) {
+               pr_err("Bad debug_guardpage_minorder value\n");
+               return 0;
+       }
+       _debug_guardpage_minorder = res;
+       pr_info("Setting debug_guardpage_minorder to %lu\n", res);
+       return 0;
+}
+early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup);
+
+bool __set_page_guard(struct zone *zone, struct page *page, unsigned int order,
+                     int migratetype)
+{
+       if (order >= debug_guardpage_minorder())
+               return false;
+
+       __SetPageGuard(page);
+       INIT_LIST_HEAD(&page->buddy_list);
+       set_page_private(page, order);
+       /* Guard pages are not available for any usage */
+       if (!is_migrate_isolate(migratetype))
+               __mod_zone_freepage_state(zone, -(1 << order), migratetype);
+
+       return true;
+}
+
+void __clear_page_guard(struct zone *zone, struct page *page, unsigned int order,
+                     int migratetype)
+{
+       __ClearPageGuard(page);
+
+       set_page_private(page, 0);
+       if (!is_migrate_isolate(migratetype))
+               __mod_zone_freepage_state(zone, (1 << order), migratetype);
+}

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 2b8e4a086c3ddf231b44c84594bb3073155f2af9..40fa763c507480c6ea261970b25f28db16804efb 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -664,75 +664,6 @@ void destroy_large_folio(struct folio *folio)
        compound_page_dtors[dtor](&folio->page);
 }
 
-#ifdef CONFIG_DEBUG_PAGEALLOC
-unsigned int _debug_guardpage_minorder;
-
-bool _debug_pagealloc_enabled_early __read_mostly
-                       = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT);
-EXPORT_SYMBOL(_debug_pagealloc_enabled_early);
-DEFINE_STATIC_KEY_FALSE(_debug_pagealloc_enabled);
-EXPORT_SYMBOL(_debug_pagealloc_enabled);
-
-DEFINE_STATIC_KEY_FALSE(_debug_guardpage_enabled);
-
-static int __init early_debug_pagealloc(char *buf)
-{
-       return kstrtobool(buf, &_debug_pagealloc_enabled_early);
-}
-early_param("debug_pagealloc", early_debug_pagealloc);
-
-static int __init debug_guardpage_minorder_setup(char *buf)
-{
-       unsigned long res;
-
-       if (kstrtoul(buf, 10, &res) < 0 ||  res > MAX_ORDER / 2) {
-               pr_err("Bad debug_guardpage_minorder value\n");
-               return 0;
-       }
-       _debug_guardpage_minorder = res;
-       pr_info("Setting debug_guardpage_minorder to %lu\n", res);
-       return 0;
-}
-early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup);
-
-static inline bool set_page_guard(struct zone *zone, struct page *page,
-                               unsigned int order, int migratetype)
-{
-       if (!debug_guardpage_enabled())
-               return false;
-
-       if (order >= debug_guardpage_minorder())
-               return false;
-
-       __SetPageGuard(page);
-       INIT_LIST_HEAD(&page->buddy_list);
-       set_page_private(page, order);
-       /* Guard pages are not available for any usage */
-       if (!is_migrate_isolate(migratetype))
-               __mod_zone_freepage_state(zone, -(1 << order), migratetype);
-
-       return true;
-}
-
-static inline void clear_page_guard(struct zone *zone, struct page *page,
-                               unsigned int order, int migratetype)
-{
-       if (!debug_guardpage_enabled())
-               return;
-
-       __ClearPageGuard(page);
-
-       set_page_private(page, 0);
-       if (!is_migrate_isolate(migratetype))
-               __mod_zone_freepage_state(zone, (1 << order), migratetype);
-}
-#else
-static inline bool set_page_guard(struct zone *zone, struct page *page,
-                       unsigned int order, int migratetype) { return false; }
-static inline void clear_page_guard(struct zone *zone, struct page *page,
-                               unsigned int order, int migratetype) {}
-#endif
-
 static inline void set_buddy_order(struct page *page, unsigned int order)
 {
        set_page_private(page, order);