readahead: compacting file_ra_state

Use 'unsigned int' instead of 'unsigned long' for readahead sizes.

This helps reduce memory consumption on 64bit CPU when a lot of files are
opened.

CC: Andi Kleen <andi@firstfloor.org>
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, 5 insertions, 5 deletions

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 4a6a21077bae..7a998c49a086 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -697,12 +697,12 @@ struct fown_struct {
  * Track a single file's readahead state
  */
 struct file_ra_state {
-        pgoff_t start;                  /* where readahead started */
-        unsigned long size;             /* # of readahead pages */
-        unsigned long async_size;       /* do asynchronous readahead when
+        pgoff_t start;                  /* where readahead started */
+        unsigned int size;              /* # of readahead pages */
+        unsigned int async_size;        /* do asynchronous readahead when
                                            there are only # of pages ahead */
 
-        unsigned long ra_pages;         /* Maximum readahead window */
+        unsigned int ra_pages;          /* Maximum readahead window */
         unsigned long mmap_hit;         /* Cache hit stat for mmap accesses */
         unsigned long mmap_miss;        /* Cache miss stat for mmap accesses */
         unsigned long prev_index;       /* Cache last read() position */
diff --git a/mm/readahead.c b/mm/readahead.c
index be20c9d699d3..d2504877b269 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -351,7 +351,7 @@ ondemand_readahead(struct address_space *mapping,
                    bool hit_readahead_marker, pgoff_t offset,
                    unsigned long req_size)
 {
-        unsigned long max;      /* max readahead pages */
+        int max;        /* max readahead pages */
         int sequential;
 
         max = ra->ra_pages;