From ee1ca48fae7e575d5e399d4fdcfe0afc1212a64c Mon Sep 17 00:00:00 2001 From: "Pallipadi, Venkatesh" Date: Thu, 21 May 2009 17:09:10 -0700 Subject: ACPI: Disable ARB_DISABLE on platforms where it is not needed ARB_DISABLE is a NOP on all of the recent Intel platforms. For such platforms, reduce contention on c3_lock by skipping the fake ARB_DISABLE. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Len Brown --- drivers/acpi/processor_idle.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'drivers/acpi/processor_idle.c') diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 72069ba5f1ed..4840c79fd8e0 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -512,7 +512,8 @@ static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx) static void acpi_processor_power_verify_c3(struct acpi_processor *pr, struct acpi_processor_cx *cx) { - static int bm_check_flag; + static int bm_check_flag = -1; + static int bm_control_flag = -1; if (!cx->address) @@ -542,12 +543,14 @@ static void acpi_processor_power_verify_c3(struct acpi_processor *pr, } /* All the logic here assumes flags.bm_check is same across all CPUs */ - if (!bm_check_flag) { + if (bm_check_flag == -1) { /* Determine whether bm_check is needed based on CPU */ acpi_processor_power_init_bm_check(&(pr->flags), pr->id); bm_check_flag = pr->flags.bm_check; + bm_control_flag = pr->flags.bm_control; } else { pr->flags.bm_check = bm_check_flag; + pr->flags.bm_control = bm_control_flag; } if (pr->flags.bm_check) { -- cgit v1.2.3 From 7e275cc4e8e20f82740bf40ae2f5695e9e35ff09 Mon Sep 17 00:00:00 2001 From: Len Brown Date: Fri, 15 May 2009 02:08:44 -0400 Subject: ACPI: idle: rename lapic timer workaround routines cosmetic only. The lapic_timer workaround routines are specific to the lapic_timer, and are not acpi-generic. old: acpi_timer_check_state() acpi_propagate_timer_broadcast() acpi_state_timer_broadcast() new: lapic_timer_check_state() lapic_timer_propagate_broadcast() lapic_timer_state_broadcast() also, simplify the code in acpi_processor_power_verify() so that lapic_timer_check_state() is simply called from one place for all valid C-states, including C1. Signed-off-by: Len Brown --- drivers/acpi/processor_idle.c | 40 ++++++++++++++++++---------------------- 1 file changed, 18 insertions(+), 22 deletions(-) (limited to 'drivers/acpi/processor_idle.c') diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 10a2d913635a..1f60ccbd4c39 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -139,7 +139,7 @@ static void acpi_safe_halt(void) * are affected too. We pick the most conservative approach: we assume * that the local APIC stops in both C2 and C3. */ -static void acpi_timer_check_state(int state, struct acpi_processor *pr, +static void lapic_timer_check_state(int state, struct acpi_processor *pr, struct acpi_processor_cx *cx) { struct acpi_processor_power *pwr = &pr->power; @@ -162,7 +162,7 @@ static void acpi_timer_check_state(int state, struct acpi_processor *pr, pr->power.timer_broadcast_on_state = state; } -static void acpi_propagate_timer_broadcast(struct acpi_processor *pr) +static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { unsigned long reason; @@ -173,7 +173,7 @@ static void acpi_propagate_timer_broadcast(struct acpi_processor *pr) } /* Power(C) State timer broadcast control */ -static void acpi_state_timer_broadcast(struct acpi_processor *pr, +static void lapic_timer_state_broadcast(struct acpi_processor *pr, struct acpi_processor_cx *cx, int broadcast) { @@ -190,10 +190,10 @@ static void acpi_state_timer_broadcast(struct acpi_processor *pr, #else -static void acpi_timer_check_state(int state, struct acpi_processor *pr, +static void lapic_timer_check_state(int state, struct acpi_processor *pr, struct acpi_processor_cx *cstate) { } -static void acpi_propagate_timer_broadcast(struct acpi_processor *pr) { } -static void acpi_state_timer_broadcast(struct acpi_processor *pr, +static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { } +static void lapic_timer_state_broadcast(struct acpi_processor *pr, struct acpi_processor_cx *cx, int broadcast) { @@ -614,29 +614,25 @@ static int acpi_processor_power_verify(struct acpi_processor *pr) switch (cx->type) { case ACPI_STATE_C1: cx->valid = 1; - acpi_timer_check_state(i, pr, cx); break; case ACPI_STATE_C2: acpi_processor_power_verify_c2(cx); - if (cx->valid) - acpi_timer_check_state(i, pr, cx); break; case ACPI_STATE_C3: acpi_processor_power_verify_c3(pr, cx); - if (cx->valid) - acpi_timer_check_state(i, pr, cx); break; } - if (cx->valid) - tsc_check_state(cx->type); + if (!cx->valid) + continue; - if (cx->valid) - working++; + lapic_timer_check_state(i, pr, cx); + tsc_check_state(cx->type); + working++; } - acpi_propagate_timer_broadcast(pr); + lapic_timer_propagate_broadcast(pr); return (working); } @@ -839,7 +835,7 @@ static int acpi_idle_enter_c1(struct cpuidle_device *dev, return 0; } - acpi_state_timer_broadcast(pr, cx, 1); + lapic_timer_state_broadcast(pr, cx, 1); kt1 = ktime_get_real(); acpi_idle_do_entry(cx); kt2 = ktime_get_real(); @@ -847,7 +843,7 @@ static int acpi_idle_enter_c1(struct cpuidle_device *dev, local_irq_enable(); cx->usage++; - acpi_state_timer_broadcast(pr, cx, 0); + lapic_timer_state_broadcast(pr, cx, 0); return idle_time; } @@ -892,7 +888,7 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev, * Must be done before busmaster disable as we might need to * access HPET ! */ - acpi_state_timer_broadcast(pr, cx, 1); + lapic_timer_state_broadcast(pr, cx, 1); if (cx->type == ACPI_STATE_C3) ACPI_FLUSH_CPU_CACHE(); @@ -914,7 +910,7 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev, cx->usage++; - acpi_state_timer_broadcast(pr, cx, 0); + lapic_timer_state_broadcast(pr, cx, 0); cx->time += sleep_ticks; return idle_time; } @@ -981,7 +977,7 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, * Must be done before busmaster disable as we might need to * access HPET ! */ - acpi_state_timer_broadcast(pr, cx, 1); + lapic_timer_state_broadcast(pr, cx, 1); kt1 = ktime_get_real(); /* @@ -1026,7 +1022,7 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, cx->usage++; - acpi_state_timer_broadcast(pr, cx, 0); + lapic_timer_state_broadcast(pr, cx, 0); cx->time += sleep_ticks; return idle_time; } -- cgit v1.2.3 From f833bab87fca5c3ce13778421b1365845843b976 Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Mon, 17 Aug 2009 14:34:59 -0700 Subject: clockevent: Prevent dead lock on clockevents_lock Currently clockevents_notify() is called with interrupts enabled at some places and interrupts disabled at some other places. This results in a deadlock in this scenario. cpu A holds clockevents_lock in clockevents_notify() with irqs enabled cpu B waits for clockevents_lock in clockevents_notify() with irqs disabled cpu C doing set_mtrr() which will try to rendezvous of all the cpus. This will result in C and A come to the rendezvous point and waiting for B. B is stuck forever waiting for the spinlock and thus not reaching the rendezvous point. Fix the clockevents code so that clockevents_lock is taken with interrupts disabled and thus avoid the above deadlock. Also call lapic_timer_propagate_broadcast() on the destination cpu so that we avoid calling smp_call_function() in the clockevents notifier chain. This issue left us wondering if we need to change the MTRR rendezvous logic to use stop machine logic (instead of smp_call_function) or add a check in spinlock debug code to see if there are other spinlocks which gets taken under both interrupts enabled/disabled conditions. Signed-off-by: Suresh Siddha Signed-off-by: Venkatesh Pallipadi Cc: "Pallipadi Venkatesh" Cc: "Brown Len" LKML-Reference: <1250544899.2709.210.camel@sbs-t61.sc.intel.com> Signed-off-by: Thomas Gleixner --- arch/x86/kernel/process.c | 6 +----- drivers/acpi/processor_idle.c | 6 ++++-- kernel/time/clockevents.c | 16 ++++++++++------ kernel/time/tick-broadcast.c | 7 +++---- 4 files changed, 18 insertions(+), 17 deletions(-) (limited to 'drivers/acpi/processor_idle.c') diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 994dd6a4a2a0..071166a4ba83 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -519,16 +519,12 @@ static void c1e_idle(void) if (!cpumask_test_cpu(cpu, c1e_mask)) { cpumask_set_cpu(cpu, c1e_mask); /* - * Force broadcast so ACPI can not interfere. Needs - * to run with interrupts enabled as it uses - * smp_function_call. + * Force broadcast so ACPI can not interfere. */ - local_irq_enable(); clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_FORCE, &cpu); printk(KERN_INFO "Switch to broadcast mode on CPU%d\n", cpu); - local_irq_disable(); } clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu); diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 0efa59e7e3af..66393d5c4c7c 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -162,8 +162,9 @@ static void lapic_timer_check_state(int state, struct acpi_processor *pr, pr->power.timer_broadcast_on_state = state; } -static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) +static void lapic_timer_propagate_broadcast(void *arg) { + struct acpi_processor *pr = (struct acpi_processor *) arg; unsigned long reason; reason = pr->power.timer_broadcast_on_state < INT_MAX ? @@ -635,7 +636,8 @@ static int acpi_processor_power_verify(struct acpi_processor *pr) working++; } - lapic_timer_propagate_broadcast(pr); + smp_call_function_single(pr->id, lapic_timer_propagate_broadcast, + pr, 1); return (working); } diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index a6dcd67b041d..620b58abdc32 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -137,11 +137,12 @@ int clockevents_program_event(struct clock_event_device *dev, ktime_t expires, */ int clockevents_register_notifier(struct notifier_block *nb) { + unsigned long flags; int ret; - spin_lock(&clockevents_lock); + spin_lock_irqsave(&clockevents_lock, flags); ret = raw_notifier_chain_register(&clockevents_chain, nb); - spin_unlock(&clockevents_lock); + spin_unlock_irqrestore(&clockevents_lock, flags); return ret; } @@ -178,16 +179,18 @@ static void clockevents_notify_released(void) */ void clockevents_register_device(struct clock_event_device *dev) { + unsigned long flags; + BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED); BUG_ON(!dev->cpumask); - spin_lock(&clockevents_lock); + spin_lock_irqsave(&clockevents_lock, flags); list_add(&dev->list, &clockevent_devices); clockevents_do_notify(CLOCK_EVT_NOTIFY_ADD, dev); clockevents_notify_released(); - spin_unlock(&clockevents_lock); + spin_unlock_irqrestore(&clockevents_lock, flags); } EXPORT_SYMBOL_GPL(clockevents_register_device); @@ -235,8 +238,9 @@ void clockevents_exchange_device(struct clock_event_device *old, void clockevents_notify(unsigned long reason, void *arg) { struct list_head *node, *tmp; + unsigned long flags; - spin_lock(&clockevents_lock); + spin_lock_irqsave(&clockevents_lock, flags); clockevents_do_notify(reason, arg); switch (reason) { @@ -251,7 +255,7 @@ void clockevents_notify(unsigned long reason, void *arg) default: break; } - spin_unlock(&clockevents_lock); + spin_unlock_irqrestore(&clockevents_lock, flags); } EXPORT_SYMBOL_GPL(clockevents_notify); #endif diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index 877dbedc3118..c2ec25087a35 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -205,11 +205,11 @@ static void tick_handle_periodic_broadcast(struct clock_event_device *dev) * Powerstate information: The system enters/leaves a state, where * affected devices might stop */ -static void tick_do_broadcast_on_off(void *why) +static void tick_do_broadcast_on_off(unsigned long *reason) { struct clock_event_device *bc, *dev; struct tick_device *td; - unsigned long flags, *reason = why; + unsigned long flags; int cpu, bc_stopped; spin_lock_irqsave(&tick_broadcast_lock, flags); @@ -276,8 +276,7 @@ void tick_broadcast_on_off(unsigned long reason, int *oncpu) printk(KERN_ERR "tick-broadcast: ignoring broadcast for " "offline CPU #%d\n", *oncpu); else - smp_call_function_single(*oncpu, tick_do_broadcast_on_off, - &reason, 1); + tick_do_broadcast_on_off(&reason); } /* -- cgit v1.2.3