diff options
Diffstat (limited to 'drivers/acpi/acpi_pad.c')
| -rw-r--r-- | drivers/acpi/acpi_pad.c | 56 |
1 files changed, 34 insertions, 22 deletions
diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c index 62122134693..446aced33af 100644 --- a/drivers/acpi/acpi_pad.c +++ b/drivers/acpi/acpi_pad.c @@ -43,6 +43,12 @@ static DEFINE_MUTEX(isolated_cpus_lock); #define CPUID5_ECX_EXTENSIONS_SUPPORTED (0x1) #define CPUID5_ECX_INTERRUPT_BREAK (0x2) static unsigned long power_saving_mwait_eax; + +static unsigned char tsc_detected_unstable; +static unsigned char tsc_marked_unstable; +static unsigned char lapic_detected_unstable; +static unsigned char lapic_marked_unstable; + static void power_saving_mwait_init(void) { unsigned int eax, ebx, ecx, edx; @@ -71,9 +77,6 @@ static void power_saving_mwait_init(void) power_saving_mwait_eax = (highest_cstate << MWAIT_SUBSTATE_SIZE) | (highest_subcstate - 1); - for_each_online_cpu(i) - clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ON, &i); - #if defined(CONFIG_GENERIC_TIME) && defined(CONFIG_X86) switch (boot_cpu_data.x86_vendor) { case X86_VENDOR_AMD: @@ -82,13 +85,15 @@ static void power_saving_mwait_init(void) * AMD Fam10h TSC will tick in all * C/P/S0/S1 states when this bit is set. */ - if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC)) - return; - - /*FALL THROUGH*/ + if (!boot_cpu_has(X86_FEATURE_NONSTOP_TSC)) + tsc_detected_unstable = 1; + if (!boot_cpu_has(X86_FEATURE_ARAT)) + lapic_detected_unstable = 1; + break; default: - /* TSC could halt in idle, so notify users */ - mark_tsc_unstable("TSC halts in idle"); + /* TSC & LAPIC could halt in idle */ + tsc_detected_unstable = 1; + lapic_detected_unstable = 1; } #endif } @@ -168,20 +173,28 @@ static int power_saving_thread(void *data) do_sleep = 0; - current_thread_info()->status &= ~TS_POLLING; - /* - * TS_POLLING-cleared state must be visible before we test - * NEED_RESCHED: - */ - smp_mb(); - expire_time = jiffies + HZ * (100 - idle_pct) / 100; while (!need_resched()) { + if (tsc_detected_unstable && !tsc_marked_unstable) { + /* TSC could halt in idle, so notify users */ + mark_tsc_unstable("TSC halts in idle"); + tsc_marked_unstable = 1; + } + if (lapic_detected_unstable && !lapic_marked_unstable) { + int i; + /* LAPIC could halt in idle, so notify users */ + for_each_online_cpu(i) + clockevents_notify( + CLOCK_EVT_NOTIFY_BROADCAST_ON, + &i); + lapic_marked_unstable = 1; + } local_irq_disable(); cpu = smp_processor_id(); - clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, - &cpu); + if (lapic_marked_unstable) + clockevents_notify( + CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu); stop_critical_timings(); __monitor((void *)¤t_thread_info()->flags, 0, 0); @@ -190,8 +203,9 @@ static int power_saving_thread(void *data) __mwait(power_saving_mwait_eax, 1); start_critical_timings(); - clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, - &cpu); + if (lapic_marked_unstable) + clockevents_notify( + CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu); local_irq_enable(); if (jiffies > expire_time) { @@ -200,8 +214,6 @@ static int power_saving_thread(void *data) } } - current_thread_info()->status |= TS_POLLING; - /* * current sched_rt has threshold for rt task running time. * When a rt task uses 95% CPU time, the rt thread will be |