• Steve Capper's avatar
    arm64: percpu: Implement this_cpu operations · f97fc810
    Steve Capper authored
    The generic this_cpu operations disable interrupts to ensure that the
    requested operation is protected from pre-emption. For arm64, this is
    overkill and can hurt throughput and latency.
    
    This patch provides arm64 specific implementations for the this_cpu
    operations. Rather than disable interrupts, we use the exclusive
    monitor or atomic operations as appropriate.
    
    The following operations are implemented: add, add_return, and, or,
    read, write, xchg. We also wire up a cmpxchg implementation from
    cmpxchg.h.
    
    Testing was performed using the percpu_test module and hackbench on a
    Juno board running 3.18-rc4.
    Signed-off-by: default avatarSteve Capper <steve.capper@linaro.org>
    Reviewed-by: default avatarWill Deacon <will.deacon@arm.com>
    Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
    f97fc810
percpu.h 6.98 KB