diff options
| author | Wu Fengguang <fengguang.wu@intel.com> | 2009-06-16 15:31:30 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-06-16 19:47:29 -0700 |
| commit | d30a11004e3411909f2448546f036a011978062e (patch) | |
| tree | c1980adb410d9fabd2c2eb8af9f0ed8ee4b656da /mm/readahead.c | |
| parent | 2fad6f5deee5556f511eab58da78737a23ddb35d (diff) | |
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>
Diffstat (limited to 'mm/readahead.c')
| -rw-r--r-- | mm/readahead.c | 23 |
1 files changed, 2 insertions, 21 deletions
diff --git a/mm/readahead.c b/mm/readahead.c index d7c6e143a12..a7f01fcce9e 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -133,15 +133,12 @@ out: } /* - * do_page_cache_readahead actually reads a chunk of disk. It allocates all + * __do_page_cache_readahead() actually reads a chunk of disk. It allocates all * the pages first, then submits them all for I/O. This avoids the very bad * behaviour which would occur if page allocations are causing VM writeback. * We really don't want to intermingle reads and writes like that. * * Returns the number of pages requested, or the maximum amount of I/O allowed. - * - * do_page_cache_readahead() returns -1 if it encountered request queue - * congestion. */ static int __do_page_cache_readahead(struct address_space *mapping, struct file *filp, @@ -232,22 +229,6 @@ int force_page_cache_readahead(struct address_space *mapping, struct file *filp, } /* - * This version skips the IO if the queue is read-congested, and will tell the - * block layer to abandon the readahead if request allocation would block. - * - * force_page_cache_readahead() will ignore queue congestion and will block on - * request queues. - */ -int do_page_cache_readahead(struct address_space *mapping, struct file *filp, - pgoff_t offset, unsigned long nr_to_read) -{ - if (bdi_read_congested(mapping->backing_dev_info)) - return -1; - - return __do_page_cache_readahead(mapping, filp, offset, nr_to_read, 0); -} - -/* * Given a desired number of PAGE_CACHE_SIZE readahead pages, return a * sensible upper limit. */ @@ -260,7 +241,7 @@ unsigned long max_sane_readahead(unsigned long nr) /* * Submit IO for the read-ahead request in file_ra_state. */ -static unsigned long ra_submit(struct file_ra_state *ra, +unsigned long ra_submit(struct file_ra_state *ra, struct address_space *mapping, struct file *filp) { int actual; |