• Nick Piggin's avatar
    splice: use get_user_pages_fast · bc40d73c
    Nick Piggin authored
    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: default avatarNick Piggin <npiggin@suse.de>
    Cc: Dave Kleikamp <shaggy@austin.ibm.com>
    Cc: Andy Whitcroft <apw@shadowen.org>
    Cc: Ingo Molnar <mingo@elte.hu>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: Andi Kleen <andi@firstfloor.org>
    Cc: Dave Kleikamp <shaggy@austin.ibm.com>
    Cc: Badari Pulavarty <pbadari@us.ibm.com>
    Cc: Zach Brown <zach.brown@oracle.com>
    Cc: Jens Axboe <jens.axboe@oracle.com>
    Reviewed-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    bc40d73c
splice.c 38.9 KB