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    Subject[PATCH 14/15] readahead: reduce MMAP_LOTSAMISS for mmap read-around
    Now that we lifts readahead size from 128KB to 512KB,
    the MMAP_LOTSAMISS shall be shrinked accordingly.

    We shrink it a bit more, so that for sparse random access patterns,
    only 10*512KB or ~5MB memory will be wasted, instead of the previous
    100*128KB or ~12MB. The new threshold "10" is still big enough to avoid
    turning off read-around for typical executable/lib page faults.

    CC: Nick Piggin <npiggin@suse.de>
    Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
    ---
    mm/filemap.c | 2 +-
    1 file changed, 1 insertion(+), 1 deletion(-)

    --- linux.orig/mm/filemap.c 2010-02-21 23:56:22.000000000 +0800
    +++ linux/mm/filemap.c 2010-02-21 23:56:26.000000000 +0800
    @@ -1393,7 +1393,7 @@ static int page_cache_read(struct file *
    return ret;
    }

    -#define MMAP_LOTSAMISS (100)
    +#define MMAP_LOTSAMISS (10)

    /*
    * Synchronous readahead happens when we don't even find



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