mm: don't inline page_mapping()
According to akpm, this saves 1/2k text and makes things simple for the
next patch.
Numbers from Minchan:
add/remove: 1/0 grow/shrink: 6/22 up/down: 92/-516 (-424)
function old new delta
page_mapping - 48 +48
do_task_stat 2292 2308 +16
page_remove_rmap 240 248 +8
load_elf_binary 4500 4508 +8
update_queue 532 536 +4
scsi_probe_and_add_lun 2892 2896 +4
lookup_fast 644 648 +4
vcs_read 1040 1036 -4
__ip_route_output_key 1904 1900 -4
ip_route_input_noref 2508 2500 -8
shmem_file_aio_read 784 772 -12
__isolate_lru_page 272 256 -16
shmem_replace_page 708 688 -20
mark_buffer_dirty 228 208 -20
__set_page_dirty_buffers 240 220 -20
__remove_mapping 276 256 -20
update_mmu_cache 500 476 -24
set_page_dirty_balance 92 68 -24
set_page_dirty 172 148 -24
page_evictable 88 64 -24
page_cache_pipe_buf_steal 248 224 -24
clear_page_dirty_for_io 340 316 -24
test_set_page_writeback 400 372 -28
test_clear_page_writeback 516 488 -28
invalidate_inode_page 156 128 -28
page_mkclean 432 400 -32
flush_dcache_page 360 328 -32
__set_page_dirty_nobuffers 324 280 -44
shrink_page_list 2412 2356 -56
Signed-off-by: Shaohua Li <shli@fusionio.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/util.c b/mm/util.c
index 3704bf1..16a73195 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -5,6 +5,7 @@
#include <linux/err.h>
#include <linux/sched.h>
#include <linux/security.h>
+#include <linux/swap.h>
#include <asm/uaccess.h>
#include "internal.h"
@@ -382,6 +383,21 @@
}
EXPORT_SYMBOL(vm_mmap);
+struct address_space *page_mapping(struct page *page)
+{
+ struct address_space *mapping = page->mapping;
+
+ VM_BUG_ON(PageSlab(page));
+#ifdef CONFIG_SWAP
+ if (unlikely(PageSwapCache(page)))
+ mapping = &swapper_space;
+ else
+#endif
+ if ((unsigned long)mapping & PAGE_MAPPING_ANON)
+ mapping = NULL;
+ return mapping;
+}
+
/* Tracepoints definitions. */
EXPORT_TRACEPOINT_SYMBOL(kmalloc);
EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);