On Tue, 2017-06-13 at 13:05:47 UTC, Nicholas Piggin wrote: > When the CPU wakes from low power state, it begins at the system reset > interrupt with the exception that caused the wakeup encoded in SRR1. > > Today, powernv idle wakeup ignores the wakeup reason (except a special > case for HMI), and the regular interrupt corresponding to the > exception will fire after the idle wakeup exits. > > Change this to replay the interrupt from the idle wakeup before > interrupts are hard-enabled. > > Test on POWER8 of context_switch selftests benchmark with polling idle > disabled (e.g., always nap, giving cross-CPU IPIs) gives the following > results: > > original wakeup direct > Different threads, same core: 315k/s 264k/s > Different cores: 235k/s 242k/s > > There is a slowdown for doorbell IPI (same core) case because system > reset wakeup does not clear the message and the doorbell interrupt > fires again needlessly. > > Signed-off-by: Nicholas Piggin <npig...@gmail.com>
Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/771d4304d07f080b6ce751e12f3579 cheers
