splice: use get_user_pages_fast

Use get_user_pages_fast in splice.  This reverts some mmap_sem batching
there, however the biggest problem with mmap_sem tends to be hold times
blocking out other threads rather than cacheline bouncing.  Further: on
architectures that implement get_user_pages_fast without locks, mmap_sem
can be avoided completely anyway.

Signed-off-by: Nick Piggin <[email protected]>
Cc: Dave Kleikamp <[email protected]>
Cc: Andy Whitcroft <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Dave Kleikamp <[email protected]>
Cc: Badari Pulavarty <[email protected]>
Cc: Zach Brown <[email protected]>
Cc: Jens Axboe <[email protected]>
Reviewed-by: Peter Zijlstra <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions