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>

diff --git a/include/linux/mm.h b/include/linux/mm.h
index fbff8e481cc44318acb8036e61cbe58dc82f935c..291c4cc06ea77f1b76503a310562fcc3f3f3de45 100644 (file)
--- 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 fd588ffc508637d8bbf17b9905e24e509aa42369..fc52f9f1b80cb08695c2379ed8faf5d761021293 100644 (file)
--- 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,