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    rcu: Deinline rcu_read_lock_sched_held() if DEBUG_LOCK_ALLOC · d5671f6b
    Denys Vlasenko 提交于
    DEBUG_LOCK_ALLOC=y is not a production setting, but it is
    not very unusual either. Many developers routinely
    use kernels built with it enabled.
    
    Apart from being selected by hand, it is also auto-selected by
    PROVE_LOCKING "Lock debugging: prove locking correctness" and
    LOCK_STAT "Lock usage statistics" config options.
    LOCK STAT is necessary for "perf lock" to work.
    
    I wouldn't spend too much time optimizing it, but this particular
    function has a very large cost in code size: when it is deinlined,
    code size decreases by 830,000 bytes:
    
        text     data      bss       dec     hex filename
    85674192 22294776 20627456 128596424 7aa39c8 vmlinux.before
    84837612 22294424 20627456 127759492 79d7484 vmlinux
    
    (with this config: http://busybox.net/~vda/kernel_config)
    Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com>
    CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
    CC: Josh Triplett <josh@joshtriplett.org>
    CC: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
    CC: Lai Jiangshan <laijs@cn.fujitsu.com>
    CC: Tejun Heo <tj@kernel.org>
    CC: Oleg Nesterov <oleg@redhat.com>
    CC: linux-kernel@vger.kernel.org
    Reviewed-by: NSteven Rostedt <rostedt@goodmis.org>
    Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
    d5671f6b
rcupdate.h 38.6 KB