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Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

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Pull timer updates from Thomas Gleixner:
 - watchdog fixes for full dynticks
 - improved debug output for full dynticks
 - remove an obsolete full dynticks check
 - two ARM SoC clocksource drivers for sharing across SoCs
 - tick broadcast fix for CPU hotplug

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tick: broadcast: Check broadcast mode on CPU hotplug
  clocksource: arm_global_timer: Add ARM global timer support
  clocksource: Add Marvell Orion SoC timer
  nohz: Remove obsolete check for full dynticks CPUs to be RCU nocbs
  watchdog: Boot-disable by default on full dynticks
  watchdog: Rename confusing state variable
  watchdog: Register / unregister watchdog kthreads on sysctl control
  nohz: Warn if the machine can not perform nohz_full
This commit is contained in:
Linus Torvalds 2013-07-13 15:36:09 -07:00
commit 0da2736686
11 changed files with 610 additions and 65 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
Documentation/devicetree/bindings/arm/global_timer.txt Normal file
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@ -0,0 +1,24 @@
* ARM Global Timer
Cortex-A9 are often associated with a per-core Global timer.
** Timer node required properties:
- compatible : Should be "arm,cortex-a9-global-timer"
Driver supports versions r2p0 and above.
- interrupts : One interrupt to each core
- reg : Specify the base address and the size of the GT timer
register window.
- clocks : Should be phandle to a clock.
Example:
timer@2c000600 {
compatible = "arm,cortex-a9-global-timer";
reg = <0x2c000600 0x20>;
interrupts = <1 13 0xf01>;
clocks = <&arm_periph_clk>;
};

17
Documentation/devicetree/bindings/timer/marvell,orion-timer.txt Normal file
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@ -0,0 +1,17 @@
Marvell Orion SoC timer
Required properties:
- compatible: shall be "marvell,orion-timer"
- reg: base address of the timer register starting with TIMERS CONTROL register
- interrupt-parent: phandle of the bridge interrupt controller
- interrupts: should contain the interrupts for Timer0 and Timer1
- clocks: phandle of timer reference clock (tclk)
Example:
timer: timer {
compatible = "marvell,orion-timer";
reg = <0x20300 0x20>;
interrupt-parent = <&bridge_intc>;
interrupts = <1>, <2>;
clocks = <&core_clk 0>;
};

18
drivers/clocksource/Kconfig
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@ -27,6 +27,11 @@ config DW_APB_TIMER_OF
config ARMADA_370_XP_TIMER
bool
config ORION_TIMER
select CLKSRC_OF
select CLKSRC_MMIO
bool
config SUN4I_TIMER
bool
@ -69,6 +74,19 @@ config ARM_ARCH_TIMER
bool
select CLKSRC_OF if OF
config ARM_GLOBAL_TIMER
bool
select CLKSRC_OF if OF
help
This options enables support for the ARM global timer unit
config CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK
bool
depends on ARM_GLOBAL_TIMER
default y
help
Use ARM global timer clock source as sched_clock
config CLKSRC_METAG_GENERIC
def_bool y if METAG
help

2
drivers/clocksource/Makefile
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@ -15,6 +15,7 @@ obj-$(CONFIG_DW_APB_TIMER_OF) += dw_apb_timer_of.o
obj-$(CONFIG_CLKSRC_NOMADIK_MTU) += nomadik-mtu.o
obj-$(CONFIG_CLKSRC_DBX500_PRCMU) += clksrc-dbx500-prcmu.o
obj-$(CONFIG_ARMADA_370_XP_TIMER) += time-armada-370-xp.o
obj-$(CONFIG_ORION_TIMER) += time-orion.o
obj-$(CONFIG_ARCH_BCM2835) += bcm2835_timer.o
obj-$(CONFIG_ARCH_MARCO) += timer-marco.o
obj-$(CONFIG_ARCH_MXS) += mxs_timer.o
@ -30,5 +31,6 @@ obj-$(CONFIG_CLKSRC_SAMSUNG_PWM) += samsung_pwm_timer.o
obj-$(CONFIG_VF_PIT_TIMER) += vf_pit_timer.o
obj-$(CONFIG_ARM_ARCH_TIMER) += arm_arch_timer.o
obj-$(CONFIG_ARM_GLOBAL_TIMER) += arm_global_timer.o
obj-$(CONFIG_CLKSRC_METAG_GENERIC) += metag_generic.o
obj-$(CONFIG_ARCH_HAS_TICK_BROADCAST) += dummy_timer.o

321
drivers/clocksource/arm_global_timer.c Normal file
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@ -0,0 +1,321 @@
/*
* drivers/clocksource/arm_global_timer.c
*
* Copyright (C) 2013 STMicroelectronics (R&D) Limited.
* Author: Stuart Menefy <stuart.menefy@st.com>
* Author: Srinivas Kandagatla <srinivas.kandagatla@st.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>
#include <linux/cpu.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>
#include <linux/sched_clock.h>
#include <asm/cputype.h>
#define GT_COUNTER0 0x00
#define GT_COUNTER1 0x04
#define GT_CONTROL 0x08
#define GT_CONTROL_TIMER_ENABLE BIT(0) /* this bit is NOT banked */
#define GT_CONTROL_COMP_ENABLE BIT(1) /* banked */
#define GT_CONTROL_IRQ_ENABLE BIT(2) /* banked */
#define GT_CONTROL_AUTO_INC BIT(3) /* banked */
#define GT_INT_STATUS 0x0c
#define GT_INT_STATUS_EVENT_FLAG BIT(0)
#define GT_COMP0 0x10
#define GT_COMP1 0x14
#define GT_AUTO_INC 0x18
/*
* We are expecting to be clocked by the ARM peripheral clock.
*
* Note: it is assumed we are using a prescaler value of zero, so this is
* the units for all operations.
*/
static void __iomem *gt_base;
static unsigned long gt_clk_rate;
static int gt_ppi;
static struct clock_event_device __percpu *gt_evt;
/*
* To get the value from the Global Timer Counter register proceed as follows:
* 1. Read the upper 32-bit timer counter register
* 2. Read the lower 32-bit timer counter register
* 3. Read the upper 32-bit timer counter register again. If the value is
* different to the 32-bit upper value read previously, go back to step 2.
* Otherwise the 64-bit timer counter value is correct.
*/
static u64 gt_counter_read(void)
{
u64 counter;
u32 lower;
u32 upper, old_upper;
upper = readl_relaxed(gt_base + GT_COUNTER1);
do {
old_upper = upper;
lower = readl_relaxed(gt_base + GT_COUNTER0);
upper = readl_relaxed(gt_base + GT_COUNTER1);
} while (upper != old_upper);
counter = upper;
counter <<= 32;
counter |= lower;
return counter;
}
/**
* To ensure that updates to comparator value register do not set the
* Interrupt Status Register proceed as follows:
* 1. Clear the Comp Enable bit in the Timer Control Register.
* 2. Write the lower 32-bit Comparator Value Register.
* 3. Write the upper 32-bit Comparator Value Register.
* 4. Set the Comp Enable bit and, if necessary, the IRQ enable bit.
*/
static void gt_compare_set(unsigned long delta, int periodic)
{
u64 counter = gt_counter_read();
unsigned long ctrl;
counter += delta;
ctrl = GT_CONTROL_TIMER_ENABLE;
writel(ctrl, gt_base + GT_CONTROL);
writel(lower_32_bits(counter), gt_base + GT_COMP0);
writel(upper_32_bits(counter), gt_base + GT_COMP1);
if (periodic) {
writel(delta, gt_base + GT_AUTO_INC);
ctrl |= GT_CONTROL_AUTO_INC;
}
ctrl |= GT_CONTROL_COMP_ENABLE | GT_CONTROL_IRQ_ENABLE;
writel(ctrl, gt_base + GT_CONTROL);
}
static void gt_clockevent_set_mode(enum clock_event_mode mode,
struct clock_event_device *clk)
{
unsigned long ctrl;
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
gt_compare_set(DIV_ROUND_CLOSEST(gt_clk_rate, HZ), 1);
break;
case CLOCK_EVT_MODE_ONESHOT:
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
ctrl = readl(gt_base + GT_CONTROL);
ctrl &= ~(GT_CONTROL_COMP_ENABLE |
GT_CONTROL_IRQ_ENABLE | GT_CONTROL_AUTO_INC);
writel(ctrl, gt_base + GT_CONTROL);
break;
default:
break;
}
}
static int gt_clockevent_set_next_event(unsigned long evt,
struct clock_event_device *unused)
{
gt_compare_set(evt, 0);
return 0;
}
static irqreturn_t gt_clockevent_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = dev_id;
if (!(readl_relaxed(gt_base + GT_INT_STATUS) &
GT_INT_STATUS_EVENT_FLAG))
return IRQ_NONE;
/**
* ERRATA 740657( Global Timer can send 2 interrupts for
* the same event in single-shot mode)
* Workaround:
* Either disable single-shot mode.
* Or
* Modify the Interrupt Handler to avoid the
* offending sequence. This is achieved by clearing
* the Global Timer flag _after_ having incremented
* the Comparator register value to a higher value.
*/
if (evt->mode == CLOCK_EVT_MODE_ONESHOT)
gt_compare_set(ULONG_MAX, 0);
writel_relaxed(GT_INT_STATUS_EVENT_FLAG, gt_base + GT_INT_STATUS);
evt->event_handler(evt);
return IRQ_HANDLED;
}
static int __cpuinit gt_clockevents_init(struct clock_event_device *clk)
{
int cpu = smp_processor_id();
clk->name = "arm_global_timer";
clk->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
clk->set_mode = gt_clockevent_set_mode;
clk->set_next_event = gt_clockevent_set_next_event;
clk->cpumask = cpumask_of(cpu);
clk->rating = 300;
clk->irq = gt_ppi;
clockevents_config_and_register(clk, gt_clk_rate,
1, 0xffffffff);
enable_percpu_irq(clk->irq, IRQ_TYPE_NONE);
return 0;
}
static void gt_clockevents_stop(struct clock_event_device *clk)
{
gt_clockevent_set_mode(CLOCK_EVT_MODE_UNUSED, clk);
disable_percpu_irq(clk->irq);
}
static cycle_t gt_clocksource_read(struct clocksource *cs)
{
return gt_counter_read();
}
static struct clocksource gt_clocksource = {
.name = "arm_global_timer",
.rating = 300,
.read = gt_clocksource_read,
.mask = CLOCKSOURCE_MASK(64),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
#ifdef CONFIG_CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK
static u32 notrace gt_sched_clock_read(void)
{
return gt_counter_read();
}
#endif
static void __init gt_clocksource_init(void)
{
writel(0, gt_base + GT_CONTROL);
writel(0, gt_base + GT_COUNTER0);
writel(0, gt_base + GT_COUNTER1);
/* enables timer on all the cores */
writel(GT_CONTROL_TIMER_ENABLE, gt_base + GT_CONTROL);
#ifdef CONFIG_CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK
setup_sched_clock(gt_sched_clock_read, 32, gt_clk_rate);
#endif
clocksource_register_hz(&gt_clocksource, gt_clk_rate);
}
static int __cpuinit gt_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
{
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_STARTING:
gt_clockevents_init(this_cpu_ptr(gt_evt));
break;
case CPU_DYING:
gt_clockevents_stop(this_cpu_ptr(gt_evt));
break;
}
return NOTIFY_OK;
}
static struct notifier_block gt_cpu_nb __cpuinitdata = {
.notifier_call = gt_cpu_notify,
};
static void __init global_timer_of_register(struct device_node *np)
{
struct clk *gt_clk;
int err = 0;
/*
* In r2p0 the comparators for each processor with the global timer
* fire when the timer value is greater than or equal to. In previous
* revisions the comparators fired when the timer value was equal to.
*/
if ((read_cpuid_id() & 0xf0000f) < 0x200000) {
pr_warn("global-timer: non support for this cpu version.\n");
return;
}
gt_ppi = irq_of_parse_and_map(np, 0);
if (!gt_ppi) {
pr_warn("global-timer: unable to parse irq\n");
return;
}
gt_base = of_iomap(np, 0);
if (!gt_base) {
pr_warn("global-timer: invalid base address\n");
return;
}
gt_clk = of_clk_get(np, 0);
if (!IS_ERR(gt_clk)) {
err = clk_prepare_enable(gt_clk);
if (err)
goto out_unmap;
} else {
pr_warn("global-timer: clk not found\n");
err = -EINVAL;
goto out_unmap;
}
gt_clk_rate = clk_get_rate(gt_clk);
gt_evt = alloc_percpu(struct clock_event_device);
if (!gt_evt) {
pr_warn("global-timer: can't allocate memory\n");
err = -ENOMEM;
goto out_clk;
}
err = request_percpu_irq(gt_ppi, gt_clockevent_interrupt,
"gt", gt_evt);
if (err) {
pr_warn("global-timer: can't register interrupt %d (%d)\n",
gt_ppi, err);
goto out_free;
}
err = register_cpu_notifier(&gt_cpu_nb);
if (err) {
pr_warn("global-timer: unable to register cpu notifier.\n");
goto out_irq;
}
/* Immediately configure the timer on the boot CPU */
gt_clocksource_init();
gt_clockevents_init(this_cpu_ptr(gt_evt));
return;
out_irq:
free_percpu_irq(gt_ppi, gt_evt);
out_free:
free_percpu(gt_evt);
out_clk:
clk_disable_unprepare(gt_clk);
out_unmap:
iounmap(gt_base);
WARN(err, "ARM Global timer register failed (%d)\n", err);
}
/* Only tested on r2p2 and r3p0 */
CLOCKSOURCE_OF_DECLARE(arm_gt, "arm,cortex-a9-global-timer",
global_timer_of_register);

150
drivers/clocksource/time-orion.c Normal file
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@ -0,0 +1,150 @@
/*
* Marvell Orion SoC timer handling.
*
* Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*
* Timer 0 is used as free-running clocksource, while timer 1 is
* used as clock_event_device.
*/
#include <linux/kernel.h>
#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/clockchips.h>
#include <linux/interrupt.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/spinlock.h>
#include <asm/sched_clock.h>
#define TIMER_CTRL 0x00
#define TIMER0_EN BIT(0)
#define TIMER0_RELOAD_EN BIT(1)
#define TIMER1_EN BIT(2)
#define TIMER1_RELOAD_EN BIT(3)
#define TIMER0_RELOAD 0x10
#define TIMER0_VAL 0x14
#define TIMER1_RELOAD 0x18
#define TIMER1_VAL 0x1c
#define ORION_ONESHOT_MIN 1
#define ORION_ONESHOT_MAX 0xfffffffe
static void __iomem *timer_base;
static DEFINE_SPINLOCK(timer_ctrl_lock);
/*
* Thread-safe access to TIMER_CTRL register
* (shared with watchdog timer)
*/
void orion_timer_ctrl_clrset(u32 clr, u32 set)
{
spin_lock(&timer_ctrl_lock);
writel((readl(timer_base + TIMER_CTRL) & ~clr) | set,
timer_base + TIMER_CTRL);
spin_unlock(&timer_ctrl_lock);
}
EXPORT_SYMBOL(orion_timer_ctrl_clrset);
/*
* Free-running clocksource handling.
*/
static u32 notrace orion_read_sched_clock(void)
{
return ~readl(timer_base + TIMER0_VAL);
}
/*
* Clockevent handling.
*/
static u32 ticks_per_jiffy;
static int orion_clkevt_next_event(unsigned long delta,
struct clock_event_device *dev)
{
/* setup and enable one-shot timer */
writel(delta, timer_base + TIMER1_VAL);
orion_timer_ctrl_clrset(TIMER1_RELOAD_EN, TIMER1_EN);
return 0;
}
static void orion_clkevt_mode(enum clock_event_mode mode,
struct clock_event_device *dev)
{
if (mode == CLOCK_EVT_MODE_PERIODIC) {
/* setup and enable periodic timer at 1/HZ intervals */
writel(ticks_per_jiffy - 1, timer_base + TIMER1_RELOAD);
writel(ticks_per_jiffy - 1, timer_base + TIMER1_VAL);
orion_timer_ctrl_clrset(0, TIMER1_RELOAD_EN | TIMER1_EN);
} else {
/* disable timer */
orion_timer_ctrl_clrset(TIMER1_RELOAD_EN | TIMER1_EN, 0);
}
}
static struct clock_event_device orion_clkevt = {
.name = "orion_event",
.features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
.shift = 32,
.rating = 300,
.set_next_event = orion_clkevt_next_event,
.set_mode = orion_clkevt_mode,
};
static irqreturn_t orion_clkevt_irq_handler(int irq, void *dev_id)
{
orion_clkevt.event_handler(&orion_clkevt);
return IRQ_HANDLED;
}
static struct irqaction orion_clkevt_irq = {
.name = "orion_event",
.flags = IRQF_TIMER,
.handler = orion_clkevt_irq_handler,
};
static void __init orion_timer_init(struct device_node *np)
{
struct clk *clk;
int irq;
/* timer registers are shared with watchdog timer */
timer_base = of_iomap(np, 0);
if (!timer_base)
panic("%s: unable to map resource\n", np->name);
clk = of_clk_get(np, 0);
if (IS_ERR(clk))
panic("%s: unable to get clk\n", np->name);
clk_prepare_enable(clk);
/* we are only interested in timer1 irq */
irq = irq_of_parse_and_map(np, 1);
if (irq <= 0)
panic("%s: unable to parse timer1 irq\n", np->name);
/* setup timer0 as free-running clocksource */
writel(~0, timer_base + TIMER0_VAL);
writel(~0, timer_base + TIMER0_RELOAD);
orion_timer_ctrl_clrset(0, TIMER0_RELOAD_EN | TIMER0_EN);
clocksource_mmio_init(timer_base + TIMER0_VAL, "orion_clocksource",
clk_get_rate(clk), 300, 32,
clocksource_mmio_readl_down);
setup_sched_clock(orion_read_sched_clock, 32, clk_get_rate(clk));
/* setup timer1 as clockevent timer */
if (setup_irq(irq, &orion_clkevt_irq))
panic("%s: unable to setup irq\n", np->name);
ticks_per_jiffy = (clk_get_rate(clk) + HZ/2) / HZ;
orion_clkevt.cpumask = cpumask_of(0);
orion_clkevt.irq = irq;
clockevents_config_and_register(&orion_clkevt, clk_get_rate(clk),
ORION_ONESHOT_MIN, ORION_ONESHOT_MAX);
}
CLOCKSOURCE_OF_DECLARE(orion_timer, "marvell,orion-timer", orion_timer_init);

2
include/linux/nmi.h
View File

@ -46,7 +46,7 @@ static inline bool trigger_all_cpu_backtrace(void)
#ifdef CONFIG_LOCKUP_DETECTOR
int hw_nmi_is_cpu_stuck(struct pt_regs *);
u64 hw_nmi_get_sample_period(int watchdog_thresh);
extern int watchdog_enabled;
extern int watchdog_user_enabled;
extern int watchdog_thresh;
struct ctl_table;
extern int proc_dowatchdog(struct ctl_table *, int ,

4
kernel/sysctl.c
View File

@ -807,7 +807,7 @@ static struct ctl_table kern_table[] = {
#if defined(CONFIG_LOCKUP_DETECTOR)
{
.procname = "watchdog",
.data = &watchdog_enabled,
.data = &watchdog_user_enabled,
.maxlen = sizeof (int),
.mode = 0644,
.proc_handler = proc_dowatchdog,
@ -834,7 +834,7 @@ static struct ctl_table kern_table[] = {
},
{
.procname = "nmi_watchdog",
.data = &watchdog_enabled,
.data = &watchdog_user_enabled,
.maxlen = sizeof (int),
.mode = 0644,
.proc_handler = proc_dowatchdog,

5
kernel/time/tick-broadcast.c
View File

@ -157,7 +157,10 @@ int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu)
dev->event_handler = tick_handle_periodic;
tick_device_setup_broadcast_func(dev);
cpumask_set_cpu(cpu, tick_broadcast_mask);
tick_broadcast_start_periodic(bc);
if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
tick_broadcast_start_periodic(bc);
else
tick_broadcast_setup_oneshot(bc);
ret = 1;
} else {
/*

15
kernel/time/tick-sched.c
View File

@ -178,6 +178,11 @@ static bool can_stop_full_tick(void)
*/
if (!sched_clock_stable) {
trace_tick_stop(0, "unstable sched clock\n");
/*
* Don't allow the user to think they can get
* full NO_HZ with this machine.
*/
WARN_ONCE(1, "NO_HZ FULL will not work with unstable sched clock");
return false;
}
#endif
@ -346,16 +351,6 @@ void __init tick_nohz_init(void)
}
cpu_notifier(tick_nohz_cpu_down_callback, 0);
/* Make sure full dynticks CPU are also RCU nocbs */
for_each_cpu(cpu, nohz_full_mask) {
if (!rcu_is_nocb_cpu(cpu)) {
pr_warning("NO_HZ: CPU %d is not RCU nocb: "
"cleared from nohz_full range", cpu);
cpumask_clear_cpu(cpu, nohz_full_mask);
}
}
cpulist_scnprintf(nohz_full_buf, sizeof(nohz_full_buf), nohz_full_mask);
pr_info("NO_HZ: Full dynticks CPUs: %s.\n", nohz_full_buf);
}

117
kernel/watchdog.c
View File

@ -29,9 +29,9 @@
#include <linux/kvm_para.h>
#include <linux/perf_event.h>
int watchdog_enabled = 1;
int watchdog_user_enabled = 1;
int __read_mostly watchdog_thresh = 10;
static int __read_mostly watchdog_disabled;
static int __read_mostly watchdog_running;
static u64 __read_mostly sample_period;
static DEFINE_PER_CPU(unsigned long, watchdog_touch_ts);
@ -63,7 +63,7 @@ static int __init hardlockup_panic_setup(char *str)
else if (!strncmp(str, "nopanic", 7))
hardlockup_panic = 0;
else if (!strncmp(str, "0", 1))
watchdog_enabled = 0;
watchdog_user_enabled = 0;
return 1;
}
__setup("nmi_watchdog=", hardlockup_panic_setup);
@ -82,7 +82,7 @@ __setup("softlockup_panic=", softlockup_panic_setup);
static int __init nowatchdog_setup(char *str)
{
watchdog_enabled = 0;
watchdog_user_enabled = 0;
return 1;
}
__setup("nowatchdog", nowatchdog_setup);
@ -90,7 +90,7 @@ __setup("nowatchdog", nowatchdog_setup);
/* deprecated */
static int __init nosoftlockup_setup(char *str)
{
watchdog_enabled = 0;
watchdog_user_enabled = 0;
return 1;
}
__setup("nosoftlockup", nosoftlockup_setup);
@ -158,7 +158,7 @@ void touch_all_softlockup_watchdogs(void)
#ifdef CONFIG_HARDLOCKUP_DETECTOR
void touch_nmi_watchdog(void)
{
if (watchdog_enabled) {
if (watchdog_user_enabled) {
unsigned cpu;
for_each_present_cpu(cpu) {
@ -347,11 +347,6 @@ static void watchdog_enable(unsigned int cpu)
hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
hrtimer->function = watchdog_timer_fn;
if (!watchdog_enabled) {
kthread_park(current);
return;
}
/* Enable the perf event */
watchdog_nmi_enable(cpu);
@ -374,6 +369,11 @@ static void watchdog_disable(unsigned int cpu)
watchdog_nmi_disable(cpu);
}
static void watchdog_cleanup(unsigned int cpu, bool online)
{
watchdog_disable(cpu);
}
static int watchdog_should_run(unsigned int cpu)
{
return __this_cpu_read(hrtimer_interrupts) !=
@ -475,28 +475,40 @@ static int watchdog_nmi_enable(unsigned int cpu) { return 0; }
static void watchdog_nmi_disable(unsigned int cpu) { return; }
#endif /* CONFIG_HARDLOCKUP_DETECTOR */
static struct smp_hotplug_thread watchdog_threads = {
.store = &softlockup_watchdog,
.thread_should_run = watchdog_should_run,
.thread_fn = watchdog,
.thread_comm = "watchdog/%u",
.setup = watchdog_enable,
.cleanup = watchdog_cleanup,
.park = watchdog_disable,
.unpark = watchdog_enable,
};
static int watchdog_enable_all_cpus(void)
{
int err = 0;
if (!watchdog_running) {
err = smpboot_register_percpu_thread(&watchdog_threads);
if (err)
pr_err("Failed to create watchdog threads, disabled\n");
else
watchdog_running = 1;
}
return err;
}
/* prepare/enable/disable routines */
/* sysctl functions */
#ifdef CONFIG_SYSCTL
static void watchdog_enable_all_cpus(void)
{
unsigned int cpu;
if (watchdog_disabled) {
watchdog_disabled = 0;
for_each_online_cpu(cpu)
kthread_unpark(per_cpu(softlockup_watchdog, cpu));
}
}
static void watchdog_disable_all_cpus(void)
{
unsigned int cpu;
if (!watchdog_disabled) {
watchdog_disabled = 1;
for_each_online_cpu(cpu)
kthread_park(per_cpu(softlockup_watchdog, cpu));
if (watchdog_running) {
watchdog_running = 0;
smpboot_unregister_percpu_thread(&watchdog_threads);
}
}
@ -507,45 +519,48 @@ static void watchdog_disable_all_cpus(void)
int proc_dowatchdog(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
int ret;
int err, old_thresh, old_enabled;
if (watchdog_disabled < 0)
return -ENODEV;
old_thresh = ACCESS_ONCE(watchdog_thresh);
old_enabled = ACCESS_ONCE(watchdog_user_enabled);
ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
if (ret || !write)
return ret;
err = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
if (err || !write)
return err;
set_sample_period();
/*
* Watchdog threads shouldn't be enabled if they are
* disabled. The 'watchdog_disabled' variable check in
* disabled. The 'watchdog_running' variable check in
* watchdog_*_all_cpus() function takes care of this.
*/
if (watchdog_enabled && watchdog_thresh)
watchdog_enable_all_cpus();
if (watchdog_user_enabled && watchdog_thresh)
err = watchdog_enable_all_cpus();
else
watchdog_disable_all_cpus();
return ret;
/* Restore old values on failure */
if (err) {
watchdog_thresh = old_thresh;
watchdog_user_enabled = old_enabled;
}
return err;
}
#endif /* CONFIG_SYSCTL */
static struct smp_hotplug_thread watchdog_threads = {
.store = &softlockup_watchdog,
.thread_should_run = watchdog_should_run,
.thread_fn = watchdog,
.thread_comm = "watchdog/%u",
.setup = watchdog_enable,
.park = watchdog_disable,
.unpark = watchdog_enable,
};
void __init lockup_detector_init(void)
{
set_sample_period();
if (smpboot_register_percpu_thread(&watchdog_threads)) {
pr_err("Failed to create watchdog threads, disabled\n");
watchdog_disabled = -ENODEV;
#ifdef CONFIG_NO_HZ_FULL
if (watchdog_user_enabled) {
watchdog_user_enabled = 0;
pr_warning("Disabled lockup detectors by default for full dynticks\n");
pr_warning("You can reactivate it with 'sysctl -w kernel.watchdog=1'\n");
}
#endif
if (watchdog_user_enabled)
watchdog_enable_all_cpus();
}