• Martin Schwidefsky's avatar
    nohz: Introduce arch_needs_cpu · 3c5d92a0
    Martin Schwidefsky authored
    Allow the architecture to request a normal jiffy tick when the system
    goes idle and tick_nohz_stop_sched_tick is called . On s390 the hook is
    used to prevent the system going fully idle if there has been an
    interrupt other than a clock comparator interrupt since the last wakeup.
    
    On s390 the HiperSockets response time for 1 connection ping-pong goes
    down from 42 to 34 microseconds. The CPU cost decreases by 27%.
    Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
    LKML-Reference: <20090929122533.402715150@de.ibm.com>
    Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
    3c5d92a0
cio.c 26.4 KB