ARC: [SMP] optimize IPI send and receive
authorVineet Gupta <vgupta@synopsys.com>
Thu, 28 Nov 2013 08:27:54 +0000 (13:57 +0530)
committerVineet Gupta <vgupta@synopsys.com>
Mon, 23 Dec 2013 06:35:04 +0000 (12:05 +0530)
commitd8e8c7dda11f5d5cf90495f2e89d917a83509bc0
tree8b8414e2bd4ed6b92bf35a36a3d891fa14399661
parentf2a4aa5646687f9a51616581221b1d348590d47e
ARC: [SMP] optimize IPI send and receive

* Don't send an IPI if receiver already has a pending IPI.
  Atomically piggyback the new msg with pending msg.

* IPI receiver looping on xchg() not required

References: https://lkml.org/lkml/2013/11/25/232
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
arch/arc/kernel/smp.c