readahead: record mmap read-around states in file_ra_state
Mmap read-around now shares the same code style and data structure with
readahead code.
This also removes do_page_cache_readahead(). Its last user, mmap
read-around, has been changed to call ra_submit().
The no-readahead-if-congested logic is dumped by the way. Users will be
pretty sensitive about the slow loading of executables. So it's
unfavorable to disabled mmap read-around on a congested queue.
[akpm@linux-foundation.org: coding-style fixes]
Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Cc: Ying Han <yinghan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/filemap.c b/mm/filemap.c
index 5c0c651..734891d 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1488,13 +1488,15 @@
if (ra->mmap_miss > MMAP_LOTSAMISS)
return;
+ /*
+ * mmap read-around
+ */
ra_pages = max_sane_readahead(ra->ra_pages);
if (ra_pages) {
- pgoff_t start = 0;
-
- if (offset > ra_pages / 2)
- start = offset - ra_pages / 2;
- do_page_cache_readahead(mapping, file, start, ra_pages);
+ ra->start = max_t(long, 0, offset - ra_pages/2);
+ ra->size = ra_pages;
+ ra->async_size = 0;
+ ra_submit(ra, mapping, file);
}
}