mm: refactor readahead defines in mm.h

All users of VM_MAX_READAHEAD actually convert it to kbytes and then to
pages. Define the macro explicitly as (SZ_128K / PAGE_SIZE). This
simplifies the expression in every filesystem. Also rename the macro to
VM_READAHEAD_PAGES to properly convey its meaning. Finally remove unused
VM_MIN_READAHEAD

[[email protected]: fix fs/io_uring.c, per Stephen]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Nikolay Borisov <[email protected]>
Reviewed-by: Matthew Wilcox <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Eric Van Hensbergen <[email protected]>
Cc: Latchesar Ionkov <[email protected]>
Cc: Dominique Martinet <[email protected]>
Cc: David Howells <[email protected]>
Cc: Chris Mason <[email protected]>
Cc: Josef Bacik <[email protected]>
Cc: David Sterba <[email protected]>
Cc: Miklos Szeredi <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions