diff options
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/kernel/sysfs.c | 4 | ||||
| -rw-r--r-- | arch/powerpc/platforms/pseries/setup.c | 24 |
2 files changed, 5 insertions, 23 deletions
diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c index 406f308ddea..d45a168bdac 100644 --- a/arch/powerpc/kernel/sysfs.c +++ b/arch/powerpc/kernel/sysfs.c @@ -25,8 +25,8 @@ static DEFINE_PER_CPU(struct cpu, cpu_devices); /* SMT stuff */ #ifdef CONFIG_PPC_MULTIPLATFORM -/* default to snooze disabled */ -DEFINE_PER_CPU(unsigned long, smt_snooze_delay); +/* Time in microseconds we delay before sleeping in the idle loop */ +DEFINE_PER_CPU(unsigned long, smt_snooze_delay) = { 100 }; static ssize_t store_smt_snooze_delay(struct sys_device *dev, const char *buf, size_t count) diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c index a6398fbe530..2551da46b2a 100644 --- a/arch/powerpc/platforms/pseries/setup.c +++ b/arch/powerpc/platforms/pseries/setup.c @@ -477,7 +477,6 @@ static void pseries_dedicated_idle_sleep(void) { unsigned int cpu = smp_processor_id(); unsigned long start_snooze; - unsigned long *smt_snooze_delay = &__get_cpu_var(smt_snooze_delay); /* * Indicate to the HV that we are idle. Now would be @@ -490,9 +489,9 @@ static void pseries_dedicated_idle_sleep(void) * has been checked recently. If we should poll for a little * while, do so. */ - if (*smt_snooze_delay) { + if (__get_cpu_var(smt_snooze_delay)) { start_snooze = get_tb() + - *smt_snooze_delay * tb_ticks_per_usec; + __get_cpu_var(smt_snooze_delay) * tb_ticks_per_usec; local_irq_enable(); set_thread_flag(TIF_POLLING_NRFLAG); @@ -512,24 +511,7 @@ static void pseries_dedicated_idle_sleep(void) goto out; } - /* - * If not SMT, cede processor. If CPU is running SMT - * cede if the other thread is not idle, so that it can - * go single-threaded. If the other thread is idle, - * we ask the hypervisor if it has pending work it - * wants to do and cede if it does. Otherwise we keep - * polling in order to reduce interrupt latency. - * - * Doing the cede when the other thread is active will - * result in this thread going dormant, meaning the other - * thread gets to run in single-threaded (ST) mode, which - * is slightly faster than SMT mode with this thread at - * very low priority. The cede enables interrupts, which - * doesn't matter here. - */ - if (!cpu_has_feature(CPU_FTR_SMT) || !lppaca[cpu ^ 1].idle - || poll_pending() == H_PENDING) - cede_processor(); + cede_processor(); out: HMT_medium(); |