linux/arch/powerpc
Nicholas Piggin 771d4304d0 powerpc/64s/idle: Process interrupts from system reset wakeup
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 <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-06-19 19:46:27 +10:00
..
boot powerpc/64: Do not link crtsaveres.o in boot 2017-05-30 14:59:51 +10:00
configs powerpc/44x/fsp2: Add defconfig for FSP2 board 2017-05-30 14:59:51 +10:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2017-05-02 15:53:46 -07:00
include powerpc/64s/idle: Process interrupts from system reset wakeup 2017-06-19 19:46:27 +10:00
kernel powerpc/64s/idle: Process interrupts from system reset wakeup 2017-06-19 19:46:27 +10:00
kvm KVM: PPC: Book3S PR: Don't include SPAPR TCE code on non-pseries platforms 2017-05-12 15:32:30 +10:00
lib powerpc/lib/xor_vmx: Ensure no altivec code executes before enable_kernel_altivec() 2017-06-02 20:17:52 +10:00
math-emu Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mm powerpc/mm/radix: Only add X for pages overlapping kernel text 2017-06-15 16:34:39 +10:00
net powerpc updates for 4.11 part 1. 2017-02-22 10:30:38 -08:00
oprofile ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
perf powerpc/perf: Add Power8 mem_access event to sysfs 2017-04-19 20:00:23 +10:00
platforms powerpc/64s/idle: Process interrupts from system reset wakeup 2017-06-19 19:46:27 +10:00
purgatory kexec, x86/purgatory: Unbreak it and clean it up 2017-03-10 20:55:09 +01:00
sysdev powerpc: Fix some spelling mistakes 2017-06-05 16:50:15 +10:00
tools powerpc/64: Tool to check head sections location sanity 2017-05-30 14:59:51 +10:00
xmon powerpc/xmon: Fix compile error with PPC_8xx=y 2017-05-30 14:59:51 +10:00
Kconfig powerpc: Remove __ilog2()s and use generic ones 2017-06-02 19:23:56 +10:00
Kconfig.debug powerpc/xmon: Enable disassembly files (compilation changes) 2017-02-15 20:02:42 +11:00
Makefile powerpc: Link warning for orphan sections 2017-05-30 14:59:51 +10:00
Makefile.postlink powerpc/64: Tool to check head sections location sanity 2017-05-30 14:59:51 +10:00