readahead: mmap read-around simplification
Fold file_ra_state.mmap_hit into file_ra_state.mmap_miss and make it an int.
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/fs.h b/include/linux/fs.h
index 7a998c4..8250811 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -703,8 +703,7 @@
there are only # of pages ahead */
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 */
+ int mmap_miss; /* Cache miss stat for mmap accesses */
unsigned long prev_index; /* Cache last read() position */
unsigned int prev_offset; /* Offset where last read() ended in a page */
};
diff --git a/mm/filemap.c b/mm/filemap.c
index 15c8413..5dc18d7 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1349,7 +1349,7 @@
* Do we miss much more than hit in this file? If so,
* stop bothering with read-ahead. It will only hurt.
*/
- if (ra->mmap_miss > ra->mmap_hit + MMAP_LOTSAMISS)
+ if (ra->mmap_miss > MMAP_LOTSAMISS)
goto no_cached_page;
/*
@@ -1375,7 +1375,7 @@
}
if (!did_readaround)
- ra->mmap_hit++;
+ ra->mmap_miss--;
/*
* We have a locked page in the page cache, now we need to check