mm: meminit: remove mminit_verify_page_links

mminit_verify_page_links() is an extremely paranoid check that was
introduced when memory initialisation was being heavily reworked.
Profiles indicated that up to 10% of parallel memory initialisation was
spent on checking this for every page.  The cost could be reduced but in
practice this check only found problems very early during the
initialisation rewrite and has found nothing since.  This patch removes an
expensive unnecessary check.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Tested-by: Nate Zimmer <nzimmer@sgi.com>
Tested-by: Waiman Long <waiman.long@hp.com>
Tested-by: Daniel J Blueman <daniel@numascale.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Robin Holt <robinmholt@gmail.com>
Cc: Nate Zimmer <nzimmer@sgi.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Waiman Long <waiman.long@hp.com>
Cc: Scott Norton <scott.norton@hp.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/internal.h b/mm/internal.h
index 71d160437205724f283a8ece5aa6139060fd6c9d..a48cbefde8cae6e6e6ce320546e3e64a92bf968d 100644 (file)
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -362,10 +362,7 @@ do { \
 } while (0)
 
 extern void mminit_verify_pageflags_layout(void);
-extern void mminit_verify_page_links(struct page *page,
-               enum zone_type zone, unsigned long nid, unsigned long pfn);
 extern void mminit_verify_zonelist(void);
-
 #else
 
 static inline void mminit_dprintk(enum mminit_level level,
@@ -377,11 +374,6 @@ static inline void mminit_verify_pageflags_layout(void)
 {
 }
 
-static inline void mminit_verify_page_links(struct page *page,
-               enum zone_type zone, unsigned long nid, unsigned long pfn)
-{
-}
-
 static inline void mminit_verify_zonelist(void)
 {
 }

diff --git a/mm/mm_init.c b/mm/mm_init.c
index 28fbf87b20aaf74479e9442e67d2937bb6a74207..fdadf918de7691a57b3611cd7c45dec250b7c732 100644 (file)
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -131,14 +131,6 @@ void __init mminit_verify_pageflags_layout(void)
        BUG_ON(or_mask != add_mask);
 }
 
-void __meminit mminit_verify_page_links(struct page *page, enum zone_type zone,
-                       unsigned long nid, unsigned long pfn)
-{
-       BUG_ON(page_to_nid(page) != nid);
-       BUG_ON(page_zonenum(page) != zone);
-       BUG_ON(page_to_pfn(page) != pfn);
-}
-
 static __init int set_mminit_loglevel(char *str)
 {
        get_option(&str, &mminit_loglevel);

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index f1f455a69cefc25e94d5db7e44b61d13866e21cf..5a38e39b30d104a149def232fe9f14acb6d64c32 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -839,7 +839,6 @@ static void __meminit __init_single_page(struct page *page, unsigned long pfn,
                                unsigned long zone, int nid)
 {
        set_page_links(page, zone, nid, pfn);
-       mminit_verify_page_links(page, zone, nid, pfn);
        init_page_count(page);
        page_mapcount_reset(page);
        page_cpupid_reset_last(page);