The patch titled
readahead: loop case
has been removed from the -mm tree. Its filename was
readahead-loop-case.patch
This patch was dropped because an updated version will be merged
------------------------------------------------------
Subject: readahead: loop case
From: Wu Fengguang <wfg@xxxxxxxxxxxxxxxx>
Disable look-ahead for loop file.
Loopback files normally contain filesystems, in which case there are already
proper look-aheads in the upper layer, more look-aheads on the loopback file
only ruins the read-ahead hit rate.
Signed-off-by: Wu Fengguang <wfg@xxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
drivers/block/loop.c | 6 ++++++
1 file changed, 6 insertions(+)
diff -puN drivers/block/loop.c~readahead-loop-case drivers/block/loop.c
--- a/drivers/block/loop.c~readahead-loop-case
+++ a/drivers/block/loop.c
@@ -755,6 +755,12 @@ static int loop_set_fd(struct loop_devic
mapping = file->f_mapping;
inode = mapping->host;
+ /*
+ * The upper layer should already do proper look-ahead,
+ * one more look-ahead here only ruins the cache hit rate.
+ */
+ file->f_ra.flags |= RA_FLAG_NO_LOOKAHEAD;
+
if (!(file->f_mode & FMODE_WRITE))
lo_flags |= LO_FLAGS_READ_ONLY;
_
Patches currently in -mm which might be from wfg@xxxxxxxxxxxxxxxx are
readahead-loop-case.patch
readahead-nfsd-case.patch
readahead-turn-on-by-default.patch
readahead-debug-radix-tree-new-functions.patch
readahead-debug-traces-showing-accessed-file-names.patch
readahead-debug-traces-showing-read-patterns.patch
readahead-remove-size-limit-on-read_ahead_kb.patch
readahead-backward-prefetching-method-fix.patch
readahead-remove-the-size-limit-of-max_sectors_kb-on-read_ahead_kb.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
