• Peter Zijlstra's avatar
    locking, sched: Introduce smp_cond_acquire() and use it · b3e0b1b6
    Peter Zijlstra authored
    Introduce smp_cond_acquire() which combines a control dependency and a
    read barrier to form acquire semantics.
    This primitive has two benefits:
     - it documents control dependencies,
     - its typically cheaper than using smp_load_acquire() in a loop.
    Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Mike Galbraith <efault@gmx.de>
    Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
qspinlock.c 13.2 KB