page_ext: move up page_ext_init() to catch early page allocation if DEFERRED_STRUCT_P...

In commit 2f1ee0913ce5 ("Revert "mm: use early_pfn_to_nid in
page_ext_init"") we call page_ext_init() after page_alloc_init_late() to
avoid some panic problem.  It seems that we cannot track early page
allocations in current kernel even if page structure has been initialized
early.

This patch moves up page_ext_init() to catch early page allocations when
DEFERRED_STRUCT_PAGE_INIT is n.  After this patch, we only need to turn
DEFERRED_STRUCT_PAGE_INIT to n then we are able to analyze the early page
allocations.  This is useful especially when we find that the free memory
value is not the same right after different kernel booting.

Link: https://lkml.kernel.org/r/20220815120954.65957-1-lizhe.67@bytedance.com
Signed-off-by: Li Zhe <lizhe.67@bytedance.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Yang Shi <yang.shi@linaro.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/page_ext.h b/include/linux/page_ext.h
index 0e259daad876b6db17a86bf4239153894a9a2fe6..92e912fd022c48ac2ee56291ec37156891137a63 100644 (file)
--- a/include/linux/page_ext.h
+++ b/include/linux/page_ext.h
@@ -43,14 +43,34 @@ extern void pgdat_page_ext_init(struct pglist_data *pgdat);
 static inline void page_ext_init_flatmem(void)
 {
 }
-extern void page_ext_init(void);
 static inline void page_ext_init_flatmem_late(void)
 {
 }
+extern void _page_ext_init(void);
+#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
+static inline void page_ext_init_early(void)
+{
+}
+static inline void page_ext_init_late(void)
+{
+       _page_ext_init();
+}
+#else
+static inline void page_ext_init_early(void)
+{
+       _page_ext_init();
+}
+static inline void page_ext_init_late(void)
+{
+}
+#endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
 #else
 extern void page_ext_init_flatmem(void);
 extern void page_ext_init_flatmem_late(void);
-static inline void page_ext_init(void)
+static inline void page_ext_init_early(void)
+{
+}
+static inline void page_ext_init_late(void)
 {
 }
 #endif
@@ -72,7 +92,11 @@ static inline void pgdat_page_ext_init(struct pglist_data *pgdat)
 {
 }
 
-static inline void page_ext_init(void)
+static inline void page_ext_init_early(void)
+{
+}
+
+static inline void page_ext_init_late(void)
 {
 }
 

diff --git a/init/main.c b/init/main.c
index 91642a4e69be62b139fd77b6f7d7791d249b54fe..7f9533ba527d533b837064500bb0716bf63e8c7e 100644 (file)
--- a/init/main.c
+++ b/init/main.c
@@ -845,6 +845,7 @@ static void __init mm_init(void)
         * slab is ready so that stack_depot_init() works properly
         */
        page_ext_init_flatmem_late();
+       page_ext_init_early();
        kmemleak_init();
        pgtable_init();
        debug_objects_mem_init();
@@ -1605,8 +1606,10 @@ static noinline void __init kernel_init_freeable(void)
 
        padata_init();
        page_alloc_init_late();
-       /* Initialize page ext after all struct pages are initialized. */
-       page_ext_init();
+       /* Initialize page ext after all struct pages are initialized if
+        * CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled
+        */
+       page_ext_init_late();
 
        do_basic_setup();
 

diff --git a/mm/page_ext.c b/mm/page_ext.c
index e1e7dfd9f3828a81cf5684ab89b8deeb8bad0848..230634f3b7dc270fac455889243473e92842828e 100644 (file)
--- a/mm/page_ext.c
+++ b/mm/page_ext.c
@@ -458,7 +458,7 @@ static int __meminit page_ext_callback(struct notifier_block *self,
        return notifier_from_errno(ret);
 }
 
-void __init page_ext_init(void)
+void __init _page_ext_init(void)
 {
        unsigned long pfn;
        int nid;