[PATCH] mm: remove PG_highmem

Remove PG_highmem, to save a page flag.  Use is_highmem() instead.  It'll
generate a little more code, but we don't use PageHigheMem() in many places.

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

7 files changed, 15 insertions, 22 deletions

diff --git a/arch/frv/mm/init.c b/arch/frv/mm/init.c
index 41958f57c838..79433159b5f0 100644
--- a/arch/frv/mm/init.c
+++ b/arch/frv/mm/init.c
@@ -169,7 +169,6 @@ void __init mem_init(void)
                 struct page *page = &mem_map[pfn];
 
                 ClearPageReserved(page);
-                set_bit(PG_highmem, &page->flags);
                 set_page_count(page, 1);
                 __free_page(page);
                 totalram_pages++;
diff --git a/arch/i386/mm/init.c b/arch/i386/mm/init.c
index 7a7ea3737265..8766c771bb45 100644
--- a/arch/i386/mm/init.c
+++ b/arch/i386/mm/init.c
@@ -269,7 +269,6 @@ void __init one_highpage_init(struct page *page, int pfn, int bad_ppro)
 {
         if (page_is_ram(pfn) && !(bad_ppro && page_kills_ppro(pfn))) {
                 ClearPageReserved(page);
-                set_bit(PG_highmem, &page->flags);
                 set_page_count(page, 1);
                 __free_page(page);
                 totalhigh_pages++;
diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index b027ce7efbc6..73843c528778 100644
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -232,7 +232,6 @@ void __init mem_init(void)
 #ifdef CONFIG_LIMITED_DMA
                 set_page_address(page, lowmem_page_address(page));
 #endif
-                set_bit(PG_highmem, &page->flags);
                 set_page_count(page, 1);
                 __free_page(page);
                 totalhigh_pages++;
diff --git a/arch/ppc/mm/init.c b/arch/ppc/mm/init.c
index 363c157e3617..c8529d004cfa 100644
--- a/arch/ppc/mm/init.c
+++ b/arch/ppc/mm/init.c
@@ -469,7 +469,6 @@ void __init mem_init(void)
                         struct page *page = mem_map + pfn;
 
                         ClearPageReserved(page);
-                        set_bit(PG_highmem, &page->flags);
                         set_page_count(page, 1);
                         __free_page(page);
                         totalhigh_pages++;
diff --git a/arch/sparc/mm/init.c b/arch/sparc/mm/init.c
index a2dea69b2f07..ec2e05028a10 100644
--- a/arch/sparc/mm/init.c
+++ b/arch/sparc/mm/init.c
@@ -384,7 +384,6 @@ void map_high_region(unsigned long start_pfn, unsigned long end_pfn)
                 struct page *page = pfn_to_page(tmp);
 
                 ClearPageReserved(page);
-                set_bit(PG_highmem, &page->flags);
                 set_page_count(page, 1);
                 __free_page(page);
                 totalhigh_pages++;
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index c22825f13e40..5597bd39e6b5 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -53,7 +53,6 @@ static void setup_highmem(unsigned long highmem_start,
         for(i = 0; i < highmem_len >> PAGE_SHIFT; i++){
                 page = &mem_map[highmem_pfn + i];
                 ClearPageReserved(page);
-                set_bit(PG_highmem, &page->flags);
                 set_page_count(page, 1);
                 __free_page(page);
         }
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 39ab8c6b5652..df313891db10 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -61,21 +61,20 @@
 #define PG_active                6
 #define PG_slab                  7      /* slab debug (Suparna wants this) */
 
-#define PG_highmem               8
-#define PG_checked               9      /* kill me in 2.5.<early>. */
-#define PG_arch_1               10
-#define PG_reserved             11
-
-#define PG_private              12      /* Has something at ->private */
-#define PG_writeback            13      /* Page is under writeback */
-#define PG_nosave               14      /* Used for system suspend/resume */
-#define PG_compound             15      /* Part of a compound page */
-
-#define PG_swapcache            16      /* Swap page: swp_entry_t in private */
-#define PG_mappedtodisk         17      /* Has blocks allocated on-disk */
-#define PG_reclaim              18      /* To be reclaimed asap */
-#define PG_nosave_free          19      /* Free, should not be written */
-#define PG_uncached             20      /* Page has been mapped as uncached */
+#define PG_checked               8      /* kill me in 2.5.<early>. */
+#define PG_arch_1                9
+#define PG_reserved             10
+#define PG_private              11      /* Has something at ->private */
+
+#define PG_writeback            12      /* Page is under writeback */
+#define PG_nosave               13      /* Used for system suspend/resume */
+#define PG_compound             14      /* Part of a compound page */
+#define PG_swapcache            15      /* Swap page: swp_entry_t in private */
+
+#define PG_mappedtodisk         16      /* Has blocks allocated on-disk */
+#define PG_reclaim              17      /* To be reclaimed asap */
+#define PG_nosave_free          18      /* Free, should not be written */
+#define PG_uncached             19      /* Page has been mapped as uncached */
 
 /*
  * Global page accounting.  One instance per CPU.  Only unsigned longs are
@@ -215,7 +214,7 @@ extern void __mod_page_state(unsigned offset, unsigned long delta);
 #define TestSetPageSlab(page)   test_and_set_bit(PG_slab, &(page)->flags)
 
 #ifdef CONFIG_HIGHMEM
-#define PageHighMem(page)       test_bit(PG_highmem, &(page)->flags)
+#define PageHighMem(page)       is_highmem(page_zone(page))
 #else
 #define PageHighMem(page)       0 /* needed to optimize away at compile time */
 #endif