readahead: remove several readahead macros

Remove VM_MAX_CACHE_HIT, MAX_RA_PAGES and MIN_RA_PAGES.

Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 1 insertions, 11 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index fbff8e481cc4..291c4cc06ea7 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1106,8 +1106,6 @@ int write_one_page(struct page *page, int wait);
 /* readahead.c */
 #define VM_MAX_READAHEAD        128     /* kbytes */
 #define VM_MIN_READAHEAD        16      /* kbytes (includes current page) */
-#define VM_MAX_CACHE_HIT        256     /* max pages in a row in cache before
-                                         * turning readahead off */
 
 int do_page_cache_readahead(struct address_space *mapping, struct file *filp,
                         pgoff_t offset, unsigned long nr_to_read);
diff --git a/mm/readahead.c b/mm/readahead.c
index fd588ffc5086..fc52f9f1b80c 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -22,16 +22,8 @@ void default_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
 }
 EXPORT_SYMBOL(default_unplug_io_fn);
 
-/*
- * Convienent macros for min/max read-ahead pages.
- * Note that MAX_RA_PAGES is rounded down, while MIN_RA_PAGES is rounded up.
- * The latter is necessary for systems with large page size(i.e. 64k).
- */
-#define MAX_RA_PAGES    (VM_MAX_READAHEAD*1024 / PAGE_CACHE_SIZE)
-#define MIN_RA_PAGES    DIV_ROUND_UP(VM_MIN_READAHEAD*1024, PAGE_CACHE_SIZE)
-
 struct backing_dev_info default_backing_dev_info = {
-        .ra_pages       = MAX_RA_PAGES,
+        .ra_pages       = VM_MAX_READAHEAD * 1024 / PAGE_CACHE_SIZE,
         .state          = 0,
         .capabilities   = BDI_CAP_MAP_COPY,
         .unplug_io_fn   = default_unplug_io_fn,