[git pull] timer updates for v2.6.29
From: Ingo Molnar
Date: Thu Dec 25 2008 - 12:14:47 EST
Linus,
Please pull the latest timers-core-for-linus git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git timers-core-for-linus
7 timer topics were active in this cycle:
timers/clocksource timers/hpet timers/hrtimers
timers/nohz timers/ntp timers/posixtimers
timers/rtc
The most significant change is the hrtimer cleanups/simplifications done
by Peter Zijlstra.
Thanks,
Ingo
------------------>
Bjorn Helgaas (1):
clocksource, acpi_pm.c: put acpi_pm_read_slow() under CONFIG_PCI
David Brownell (1):
rtc-cmos: export second NVRAM bank
Denis V. Lunev (1):
x86: correct link to HPET timer specification
Heiko Carstens (1):
nohz: no softirq pending warnings for offline cpus
Ingo Molnar (1):
hrtimers: fix warning in kernel/hrtimer.c
Janne Kulmala (1):
x86: enable HPET on Fujitsu u9200
Jeremy Fitzhardinge (1):
x86: make sure we really have an hpet mapping before using it
Mike Frysinger (1):
linux/timex.h: cleanup for userspace
Oleg Nesterov (3):
posix-timers: use "struct pid*" instead of "struct task_struct*"
posix-timers: check ->it_signal instead of ->it_pid to validate the timer
posix-timers: simplify de_thread()->exit_itimers() path
Peter Zijlstra (3):
hrtimer: removing all ur callback modes
hrtimer: removing all ur callback modes, fix hotplug
hrtimer: removing all ur callback modes, fix
Woodruff, Richard (1):
nohz: suppress needless timer reprogramming
arch/x86/Kconfig | 2 +-
arch/x86/kernel/hpet.c | 7 +-
arch/x86/kernel/quirks.c | 2 +
drivers/char/hpet.c | 2 +-
drivers/clocksource/acpi_pm.c | 10 +-
drivers/input/touchscreen/ads7846.c | 4 +-
fs/exec.c | 8 +-
include/linux/hrtimer.h | 34 +----
include/linux/interrupt.h | 3 -
include/linux/posix-timers.h | 6 +-
include/linux/timex.h | 73 ++++----
kernel/hrtimer.c | 331 +++++++----------------------------
kernel/posix-timers.c | 40 ++--
kernel/sched.c | 2 -
kernel/time/ntp.c | 4 +-
kernel/time/tick-sched.c | 44 +++--
kernel/trace/trace_sysprof.c | 1 -
sound/drivers/pcsp/pcsp.c | 1 -
18 files changed, 169 insertions(+), 405 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index ac22bb7..19f0d97 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -482,7 +482,7 @@ config HPET_TIMER
The HPET provides a stable time base on SMP
systems, unlike the TSC, but it is more expensive to access,
as it is off-chip. You can find the HPET spec at
- <http://www.intel.com/hardwaredesign/hpetspec.htm>.
+ <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
You can safely choose Y here. However, HPET will only be
activated if the platform and the BIOS support this feature.
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 067d8de..a1f6ed5 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -811,7 +811,7 @@ int __init hpet_enable(void)
out_nohpet:
hpet_clear_mapping();
- boot_hpet_disable = 1;
+ hpet_address = 0;
return 0;
}
@@ -834,10 +834,11 @@ static __init int hpet_late_init(void)
hpet_address = force_hpet_address;
hpet_enable();
- if (!hpet_virt_address)
- return -ENODEV;
}
+ if (!hpet_virt_address)
+ return -ENODEV;
+
hpet_reserve_platform_timers(hpet_readl(HPET_ID));
for_each_online_cpu(cpu) {
diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
index 67465ed..309949e 100644
--- a/arch/x86/kernel/quirks.c
+++ b/arch/x86/kernel/quirks.c
@@ -168,6 +168,8 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH7_31,
ich_force_enable_hpet);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH8_1,
ich_force_enable_hpet);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH8_4,
+ ich_force_enable_hpet);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH9_7,
ich_force_enable_hpet);
diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index 53fdc7f..32b8bbf 100644
--- a/drivers/char/hpet.c
+++ b/drivers/char/hpet.c
@@ -46,7 +46,7 @@
/*
* The High Precision Event Timer driver.
* This driver is closely modelled after the rtc.c driver.
- * http://www.intel.com/hardwaredesign/hpetspec.htm
+ * http://www.intel.com/hardwaredesign/hpetspec_1.pdf
*/
#define HPET_USER_FREQ (64)
#define HPET_DRIFT (500)
diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c
index c201710..e1129fa 100644
--- a/drivers/clocksource/acpi_pm.c
+++ b/drivers/clocksource/acpi_pm.c
@@ -57,11 +57,6 @@ u32 acpi_pm_read_verified(void)
return v2;
}
-static cycle_t acpi_pm_read_slow(void)
-{
- return (cycle_t)acpi_pm_read_verified();
-}
-
static cycle_t acpi_pm_read(void)
{
return (cycle_t)read_pmtmr();
@@ -88,6 +83,11 @@ static int __init acpi_pm_good_setup(char *__str)
}
__setup("acpi_pm_good", acpi_pm_good_setup);
+static cycle_t acpi_pm_read_slow(void)
+{
+ return (cycle_t)acpi_pm_read_verified();
+}
+
static inline void acpi_pm_need_workaround(void)
{
clocksource_acpi_pm.read = acpi_pm_read_slow;
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index b9b7fc6..e1ece89 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -697,7 +697,7 @@ static enum hrtimer_restart ads7846_timer(struct hrtimer *handle)
struct ads7846 *ts = container_of(handle, struct ads7846, timer);
int status = 0;
- spin_lock_irq(&ts->lock);
+ spin_lock(&ts->lock);
if (unlikely(!get_pendown_state(ts) ||
device_suspended(&ts->spi->dev))) {
@@ -728,7 +728,7 @@ static enum hrtimer_restart ads7846_timer(struct hrtimer *handle)
dev_err(&ts->spi->dev, "spi_async --> %d\n", status);
}
- spin_unlock_irq(&ts->lock);
+ spin_unlock(&ts->lock);
return HRTIMER_NORESTART;
}
diff --git a/fs/exec.c b/fs/exec.c
index ec5df9a..b4e5b8a 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -772,7 +772,6 @@ static int de_thread(struct task_struct *tsk)
struct signal_struct *sig = tsk->signal;
struct sighand_struct *oldsighand = tsk->sighand;
spinlock_t *lock = &oldsighand->siglock;
- struct task_struct *leader = NULL;
int count;
if (thread_group_empty(tsk))
@@ -810,7 +809,7 @@ static int de_thread(struct task_struct *tsk)
* and to assume its PID:
*/
if (!thread_group_leader(tsk)) {
- leader = tsk->group_leader;
+ struct task_struct *leader = tsk->group_leader;
sig->notify_count = -1; /* for exit_notify() */
for (;;) {
@@ -862,8 +861,9 @@ static int de_thread(struct task_struct *tsk)
BUG_ON(leader->exit_state != EXIT_ZOMBIE);
leader->exit_state = EXIT_DEAD;
-
write_unlock_irq(&tasklist_lock);
+
+ release_task(leader);
}
sig->group_exit_task = NULL;
@@ -872,8 +872,6 @@ static int de_thread(struct task_struct *tsk)
no_thread_group:
exit_itimers(sig);
flush_itimer_signals();
- if (leader)
- release_task(leader);
if (atomic_read(&oldsighand->count) != 1) {
struct sighand_struct *newsighand;
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index 3eba438..bd37078 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -43,26 +43,6 @@ enum hrtimer_restart {
};
/*
- * hrtimer callback modes:
- *
- * HRTIMER_CB_SOFTIRQ: Callback must run in softirq context
- * HRTIMER_CB_IRQSAFE_PERCPU: Callback must run in hardirq context
- * Special mode for tick emulation and
- * scheduler timer. Such timers are per
- * cpu and not allowed to be migrated on
- * cpu unplug.
- * HRTIMER_CB_IRQSAFE_UNLOCKED: Callback should run in hardirq context
- * with timer->base lock unlocked
- * used for timers which call wakeup to
- * avoid lock order problems with rq->lock
- */
-enum hrtimer_cb_mode {
- HRTIMER_CB_SOFTIRQ,
- HRTIMER_CB_IRQSAFE_PERCPU,
- HRTIMER_CB_IRQSAFE_UNLOCKED,
-};
-
-/*
* Values to track state of the timer
*
* Possible states:
@@ -70,7 +50,6 @@ enum hrtimer_cb_mode {
* 0x00 inactive
* 0x01 enqueued into rbtree
* 0x02 callback function running
- * 0x04 callback pending (high resolution mode)
*
* Special cases:
* 0x03 callback function running and enqueued
@@ -92,8 +71,7 @@ enum hrtimer_cb_mode {
#define HRTIMER_STATE_INACTIVE 0x00
#define HRTIMER_STATE_ENQUEUED 0x01
#define HRTIMER_STATE_CALLBACK 0x02
-#define HRTIMER_STATE_PENDING 0x04
-#define HRTIMER_STATE_MIGRATE 0x08
+#define HRTIMER_STATE_MIGRATE 0x04
/**
* struct hrtimer - the basic hrtimer structure
@@ -109,8 +87,6 @@ enum hrtimer_cb_mode {
* @function: timer expiry callback function
* @base: pointer to the timer base (per cpu and per clock)
* @state: state information (See bit values above)
- * @cb_mode: high resolution timer feature to select the callback execution
- * mode
* @cb_entry: list head to enqueue an expired timer into the callback list
* @start_site: timer statistics field to store the site where the timer
* was started
@@ -129,7 +105,6 @@ struct hrtimer {
struct hrtimer_clock_base *base;
unsigned long state;
struct list_head cb_entry;
- enum hrtimer_cb_mode cb_mode;
#ifdef CONFIG_TIMER_STATS
int start_pid;
void *start_site;
@@ -188,15 +163,11 @@ struct hrtimer_clock_base {
* @check_clocks: Indictator, when set evaluate time source and clock
* event devices whether high resolution mode can be
* activated.
- * @cb_pending: Expired timers are moved from the rbtree to this
- * list in the timer interrupt. The list is processed
- * in the softirq.
* @nr_events: Total number of timer interrupt events
*/
struct hrtimer_cpu_base {
spinlock_t lock;
struct hrtimer_clock_base clock_base[HRTIMER_MAX_CLOCK_BASES];
- struct list_head cb_pending;
#ifdef CONFIG_HIGH_RES_TIMERS
ktime_t expires_next;
int hres_active;
@@ -404,8 +375,7 @@ static inline int hrtimer_active(const struct hrtimer *timer)
*/
static inline int hrtimer_is_queued(struct hrtimer *timer)
{
- return timer->state &
- (HRTIMER_STATE_ENQUEUED | HRTIMER_STATE_PENDING);
+ return timer->state & HRTIMER_STATE_ENQUEUED;
}
/*
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index f58a0cf..d6210a9 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -251,9 +251,6 @@ enum
BLOCK_SOFTIRQ,
TASKLET_SOFTIRQ,
SCHED_SOFTIRQ,
-#ifdef CONFIG_HIGH_RES_TIMERS
- HRTIMER_SOFTIRQ,
-#endif
RCU_SOFTIRQ, /* Preferable RCU should always be the last softirq */
NR_SOFTIRQS
diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h
index a7c7213..4f71bf4 100644
--- a/include/linux/posix-timers.h
+++ b/include/linux/posix-timers.h
@@ -45,7 +45,11 @@ struct k_itimer {
int it_requeue_pending; /* waiting to requeue this timer */
#define REQUEUE_PENDING 1
int it_sigev_notify; /* notify word of sigevent struct */
- struct task_struct *it_process; /* process to send signal to */
+ struct signal_struct *it_signal;
+ union {
+ struct pid *it_pid; /* pid of process to send signal to */
+ struct task_struct *it_process; /* for clock_nanosleep */
+ };
struct sigqueue *sigq; /* signal queue entry. */
union {
struct {
diff --git a/include/linux/timex.h b/include/linux/timex.h
index 9007313..998a55d 100644
--- a/include/linux/timex.h
+++ b/include/linux/timex.h
@@ -53,47 +53,11 @@
#ifndef _LINUX_TIMEX_H
#define _LINUX_TIMEX_H
-#include <linux/compiler.h>
#include <linux/time.h>
-#include <asm/param.h>
-
#define NTP_API 4 /* NTP API version */
/*
- * SHIFT_KG and SHIFT_KF establish the damping of the PLL and are chosen
- * for a slightly underdamped convergence characteristic. SHIFT_KH
- * establishes the damping of the FLL and is chosen by wisdom and black
- * art.
- *
- * MAXTC establishes the maximum time constant of the PLL. With the
- * SHIFT_KG and SHIFT_KF values given and a time constant range from
- * zero to MAXTC, the PLL will converge in 15 minutes to 16 hours,
- * respectively.
- */
-#define SHIFT_PLL 4 /* PLL frequency factor (shift) */
-#define SHIFT_FLL 2 /* FLL frequency factor (shift) */
-#define MAXTC 10 /* maximum time constant (shift) */
-
-/*
- * SHIFT_USEC defines the scaling (shift) of the time_freq and
- * time_tolerance variables, which represent the current frequency
- * offset and maximum frequency tolerance.
- */
-#define SHIFT_USEC 16 /* frequency offset scale (shift) */
-#define PPM_SCALE (NSEC_PER_USEC << (NTP_SCALE_SHIFT - SHIFT_USEC))
-#define PPM_SCALE_INV_SHIFT 19
-#define PPM_SCALE_INV ((1ll << (PPM_SCALE_INV_SHIFT + NTP_SCALE_SHIFT)) / \
- PPM_SCALE + 1)
-
-#define MAXPHASE 500000000l /* max phase error (ns) */
-#define MAXFREQ 500000 /* max frequency error (ns/s) */
-#define MAXFREQ_SCALED ((s64)MAXFREQ << NTP_SCALE_SHIFT)
-#define MINSEC 256 /* min interval between updates (s) */
-#define MAXSEC 2048 /* max interval between updates (s) */
-#define NTP_PHASE_LIMIT ((MAXPHASE / NSEC_PER_USEC) << 5) /* beyond max. dispersion */
-
-/*
* syscall interface - used (mainly by NTP daemon)
* to discipline kernel clock oscillator
*/
@@ -199,9 +163,46 @@ struct timex {
#define TIME_BAD TIME_ERROR /* bw compat */
#ifdef __KERNEL__
+#include <linux/compiler.h>
+#include <linux/types.h>
+#include <linux/param.h>
+
#include <asm/timex.h>
/*
+ * SHIFT_KG and SHIFT_KF establish the damping of the PLL and are chosen
+ * for a slightly underdamped convergence characteristic. SHIFT_KH
+ * establishes the damping of the FLL and is chosen by wisdom and black
+ * art.
+ *
+ * MAXTC establishes the maximum time constant of the PLL. With the
+ * SHIFT_KG and SHIFT_KF values given and a time constant range from
+ * zero to MAXTC, the PLL will converge in 15 minutes to 16 hours,
+ * respectively.
+ */
+#define SHIFT_PLL 4 /* PLL frequency factor (shift) */
+#define SHIFT_FLL 2 /* FLL frequency factor (shift) */
+#define MAXTC 10 /* maximum time constant (shift) */
+
+/*
+ * SHIFT_USEC defines the scaling (shift) of the time_freq and
+ * time_tolerance variables, which represent the current frequency
+ * offset and maximum frequency tolerance.
+ */
+#define SHIFT_USEC 16 /* frequency offset scale (shift) */
+#define PPM_SCALE (NSEC_PER_USEC << (NTP_SCALE_SHIFT - SHIFT_USEC))
+#define PPM_SCALE_INV_SHIFT 19
+#define PPM_SCALE_INV ((1ll << (PPM_SCALE_INV_SHIFT + NTP_SCALE_SHIFT)) / \
+ PPM_SCALE + 1)
+
+#define MAXPHASE 500000000l /* max phase error (ns) */
+#define MAXFREQ 500000 /* max frequency error (ns/s) */
+#define MAXFREQ_SCALED ((s64)MAXFREQ << NTP_SCALE_SHIFT)
+#define MINSEC 256 /* min interval between updates (s) */
+#define MAXSEC 2048 /* max interval between updates (s) */
+#define NTP_PHASE_LIMIT ((MAXPHASE / NSEC_PER_USEC) << 5) /* beyond max. dispersion */
+
+/*
* kernel variables
* Note: maximum error = NTP synch distance = dispersion + delay / 2;
* estimated error = NTP dispersion.
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 47e6334..bda9cb9 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -442,22 +442,6 @@ static inline void debug_hrtimer_activate(struct hrtimer *timer) { }
static inline void debug_hrtimer_deactivate(struct hrtimer *timer) { }
#endif
-/*
- * Check, whether the timer is on the callback pending list
- */
-static inline int hrtimer_cb_pending(const struct hrtimer *timer)
-{
- return timer->state & HRTIMER_STATE_PENDING;
-}
-
-/*
- * Remove a timer from the callback pending list
- */
-static inline void hrtimer_remove_cb_pending(struct hrtimer *timer)
-{
- list_del_init(&timer->cb_entry);
-}
-
/* High resolution timer related functions */
#ifdef CONFIG_HIGH_RES_TIMERS
@@ -651,6 +635,8 @@ static inline void hrtimer_init_timer_hres(struct hrtimer *timer)
{
}
+static void __run_hrtimer(struct hrtimer *timer);
+
/*
* When High resolution timers are active, try to reprogram. Note, that in case
* the state has HRTIMER_STATE_CALLBACK set, no reprogramming and no expiry
@@ -661,31 +647,14 @@ static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
struct hrtimer_clock_base *base)
{
if (base->cpu_base->hres_active && hrtimer_reprogram(timer, base)) {
-
- /* Timer is expired, act upon the callback mode */
- switch(timer->cb_mode) {
- case HRTIMER_CB_IRQSAFE_PERCPU:
- case HRTIMER_CB_IRQSAFE_UNLOCKED:
- /*
- * This is solely for the sched tick emulation with
- * dynamic tick support to ensure that we do not
- * restart the tick right on the edge and end up with
- * the tick timer in the softirq ! The calling site
- * takes care of this. Also used for hrtimer sleeper !
- */
- debug_hrtimer_deactivate(timer);
- return 1;
- case HRTIMER_CB_SOFTIRQ:
- /*
- * Move everything else into the softirq pending list !
- */
- list_add_tail(&timer->cb_entry,
- &base->cpu_base->cb_pending);
- timer->state = HRTIMER_STATE_PENDING;
- return 1;
- default:
- BUG();
- }
+ /*
+ * XXX: recursion check?
+ * hrtimer_forward() should round up with timer granularity
+ * so that we never get into inf recursion here,
+ * it doesn't do that though
+ */
+ __run_hrtimer(timer);
+ return 1;
}
return 0;
}
@@ -724,11 +693,6 @@ static int hrtimer_switch_to_hres(void)
return 1;
}
-static inline void hrtimer_raise_softirq(void)
-{
- raise_softirq(HRTIMER_SOFTIRQ);
-}
-
#else
static inline int hrtimer_hres_active(void) { return 0; }
@@ -747,7 +711,6 @@ static inline int hrtimer_reprogram(struct hrtimer *timer,
{
return 0;
}
-static inline void hrtimer_raise_softirq(void) { }
#endif /* CONFIG_HIGH_RES_TIMERS */
@@ -890,10 +853,7 @@ static void __remove_hrtimer(struct hrtimer *timer,
struct hrtimer_clock_base *base,
unsigned long newstate, int reprogram)
{
- /* High res. callback list. NOP for !HIGHRES */
- if (hrtimer_cb_pending(timer))
- hrtimer_remove_cb_pending(timer);
- else {
+ if (timer->state & HRTIMER_STATE_ENQUEUED) {
/*
* Remove the timer from the rbtree and replace the
* first entry pointer if necessary.
@@ -953,7 +913,7 @@ hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, unsigned long delta_n
{
struct hrtimer_clock_base *base, *new_base;
unsigned long flags;
- int ret, raise;
+ int ret;
base = lock_hrtimer_base(timer, &flags);
@@ -988,26 +948,8 @@ hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, unsigned long delta_n
enqueue_hrtimer(timer, new_base,
new_base->cpu_base == &__get_cpu_var(hrtimer_bases));
- /*
- * The timer may be expired and moved to the cb_pending
- * list. We can not raise the softirq with base lock held due
- * to a possible deadlock with runqueue lock.
- */
- raise = timer->state == HRTIMER_STATE_PENDING;
-
- /*
- * We use preempt_disable to prevent this task from migrating after
- * setting up the softirq and raising it. Otherwise, if me migrate
- * we will raise the softirq on the wrong CPU.
- */
- preempt_disable();
-
unlock_hrtimer_base(timer, &flags);
- if (raise)
- hrtimer_raise_softirq();
- preempt_enable();
-
return ret;
}
EXPORT_SYMBOL_GPL(hrtimer_start_range_ns);
@@ -1192,75 +1134,6 @@ int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp)
}
EXPORT_SYMBOL_GPL(hrtimer_get_res);
-static void run_hrtimer_pending(struct hrtimer_cpu_base *cpu_base)
-{
- spin_lock_irq(&cpu_base->lock);
-
- while (!list_empty(&cpu_base->cb_pending)) {
- enum hrtimer_restart (*fn)(struct hrtimer *);
- struct hrtimer *timer;
- int restart;
- int emulate_hardirq_ctx = 0;
-
- timer = list_entry(cpu_base->cb_pending.next,
- struct hrtimer, cb_entry);
-
- debug_hrtimer_deactivate(timer);
- timer_stats_account_hrtimer(timer);
-
- fn = timer->function;
- /*
- * A timer might have been added to the cb_pending list
- * when it was migrated during a cpu-offline operation.
- * Emulate hardirq context for such timers.
- */
- if (timer->cb_mode == HRTIMER_CB_IRQSAFE_PERCPU ||
- timer->cb_mode == HRTIMER_CB_IRQSAFE_UNLOCKED)
- emulate_hardirq_ctx = 1;
-
- __remove_hrtimer(timer, timer->base, HRTIMER_STATE_CALLBACK, 0);
- spin_unlock_irq(&cpu_base->lock);
-
- if (unlikely(emulate_hardirq_ctx)) {
- local_irq_disable();
- restart = fn(timer);
- local_irq_enable();
- } else
- restart = fn(timer);
-
- spin_lock_irq(&cpu_base->lock);
-
- timer->state &= ~HRTIMER_STATE_CALLBACK;
- if (restart == HRTIMER_RESTART) {
- BUG_ON(hrtimer_active(timer));
- /*
- * Enqueue the timer, allow reprogramming of the event
- * device
- */
- enqueue_hrtimer(timer, timer->base, 1);
- } else if (hrtimer_active(timer)) {
- /*
- * If the timer was rearmed on another CPU, reprogram
- * the event device.
- */
- struct hrtimer_clock_base *base = timer->base;
-
- if (base->first == &timer->node &&
- hrtimer_reprogram(timer, base)) {
- /*
- * Timer is expired. Thus move it from tree to
- * pending list again.
- */
- __remove_hrtimer(timer, base,
- HRTIMER_STATE_PENDING, 0);
- list_add_tail(&timer->cb_entry,
- &base->cpu_base->cb_pending);
- }
- }
- }
- spin_unlock_irq(&cpu_base->lock);
-}
-
static void __run_hrtimer(struct hrtimer *timer)
{
struct hrtimer_clock_base *base = timer->base;
@@ -1268,25 +1141,21 @@ static void __run_hrtimer(struct hrtimer *timer)
enum hrtimer_restart (*fn)(struct hrtimer *);
int restart;
+ WARN_ON(!irqs_disabled());
+
debug_hrtimer_deactivate(timer);
__remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0);
timer_stats_account_hrtimer(timer);
-
fn = timer->function;
- if (timer->cb_mode == HRTIMER_CB_IRQSAFE_PERCPU ||
- timer->cb_mode == HRTIMER_CB_IRQSAFE_UNLOCKED) {
- /*
- * Used for scheduler timers, avoid lock inversion with
- * rq->lock and tasklist_lock.
- *
- * These timers are required to deal with enqueue expiry
- * themselves and are not allowed to migrate.
- */
- spin_unlock(&cpu_base->lock);
- restart = fn(timer);
- spin_lock(&cpu_base->lock);
- } else
- restart = fn(timer);
+
+ /*
+ * Because we run timers from hardirq context, there is no chance
+ * they get migrated to another cpu, therefore its safe to unlock
+ * the timer base.
+ */
+ spin_unlock(&cpu_base->lock);
+ restart = fn(timer);
+ spin_lock(&cpu_base->lock);
/*
* Note: We clear the CALLBACK bit after enqueue_hrtimer to avoid
@@ -1311,7 +1180,7 @@ void hrtimer_interrupt(struct clock_event_device *dev)
struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
struct hrtimer_clock_base *base;
ktime_t expires_next, now;
- int i, raise = 0;
+ int i;
BUG_ON(!cpu_base->hres_active);
cpu_base->nr_events++;
@@ -1360,16 +1229,6 @@ void hrtimer_interrupt(struct clock_event_device *dev)
break;
}
- /* Move softirq callbacks to the pending list */
- if (timer->cb_mode == HRTIMER_CB_SOFTIRQ) {
- __remove_hrtimer(timer, base,
- HRTIMER_STATE_PENDING, 0);
- list_add_tail(&timer->cb_entry,
- &base->cpu_base->cb_pending);
- raise = 1;
- continue;
- }
-
__run_hrtimer(timer);
}
spin_unlock(&cpu_base->lock);
@@ -1383,10 +1242,6 @@ void hrtimer_interrupt(struct clock_event_device *dev)
if (tick_program_event(expires_next, 0))
goto retry;
}
-
- /* Raise softirq ? */
- if (raise)
- raise_softirq(HRTIMER_SOFTIRQ);
}
/**
@@ -1413,11 +1268,6 @@ void hrtimer_peek_ahead_timers(void)
local_irq_restore(flags);
}
-static void run_hrtimer_softirq(struct softirq_action *h)
-{
- run_hrtimer_pending(&__get_cpu_var(hrtimer_bases));
-}
-
#endif /* CONFIG_HIGH_RES_TIMERS */
/*
@@ -1429,8 +1279,6 @@ static void run_hrtimer_softirq(struct softirq_action *h)
*/
void hrtimer_run_pending(void)
{
- struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
-
if (hrtimer_hres_active())
return;
@@ -1444,8 +1292,6 @@ void hrtimer_run_pending(void)
*/
if (tick_check_oneshot_change(!hrtimer_is_hres_enabled()))
hrtimer_switch_to_hres();
-
- run_hrtimer_pending(cpu_base);
}
/*
@@ -1482,14 +1328,6 @@ void hrtimer_run_queues(void)
hrtimer_get_expires_tv64(timer))
break;
- if (timer->cb_mode == HRTIMER_CB_SOFTIRQ) {
- __remove_hrtimer(timer, base,
- HRTIMER_STATE_PENDING, 0);
- list_add_tail(&timer->cb_entry,
- &base->cpu_base->cb_pending);
- continue;
- }
-
__run_hrtimer(timer);
}
spin_unlock(&cpu_base->lock);
@@ -1516,9 +1354,6 @@ void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task)
{
sl->timer.function = hrtimer_wakeup;
sl->task = task;
-#ifdef CONFIG_HIGH_RES_TIMERS
- sl->timer.cb_mode = HRTIMER_CB_IRQSAFE_UNLOCKED;
-#endif
}
static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode)
@@ -1655,18 +1490,16 @@ static void __cpuinit init_hrtimers_cpu(int cpu)
for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++)
cpu_base->clock_base[i].cpu_base = cpu_base;
- INIT_LIST_HEAD(&cpu_base->cb_pending);
hrtimer_init_hres(cpu_base);
}
#ifdef CONFIG_HOTPLUG_CPU
-static int migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
- struct hrtimer_clock_base *new_base, int dcpu)
+static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
+ struct hrtimer_clock_base *new_base)
{
struct hrtimer *timer;
struct rb_node *node;
- int raise = 0;
while ((node = rb_first(&old_base->active))) {
timer = rb_entry(node, struct hrtimer, node);
@@ -1674,18 +1507,6 @@ static int migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
debug_hrtimer_deactivate(timer);
/*
- * Should not happen. Per CPU timers should be
- * canceled _before_ the migration code is called
- */
- if (timer->cb_mode == HRTIMER_CB_IRQSAFE_PERCPU) {
- __remove_hrtimer(timer, old_base,
- HRTIMER_STATE_INACTIVE, 0);
- WARN(1, "hrtimer (%p %p)active but cpu %d dead\n",
- timer, timer->function, dcpu);
- continue;
- }
-
- /*
* Mark it as STATE_MIGRATE not INACTIVE otherwise the
* timer could be seen as !active and just vanish away
* under us on another CPU
@@ -1693,69 +1514,34 @@ static int migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
__remove_hrtimer(timer, old_base, HRTIMER_STATE_MIGRATE, 0);
timer->base = new_base;
/*
- * Enqueue the timer. Allow reprogramming of the event device
+ * Enqueue the timers on the new cpu, but do not reprogram
+ * the timer as that would enable a deadlock between
+ * hrtimer_enqueue_reprogramm() running the timer and us still
+ * holding a nested base lock.
+ *
+ * Instead we tickle the hrtimer interrupt after the migration
+ * is done, which will run all expired timers and re-programm
+ * the timer device.
*/
- enqueue_hrtimer(timer, new_base, 1);
+ enqueue_hrtimer(timer, new_base, 0);
-#ifdef CONFIG_HIGH_RES_TIMERS
- /*
- * Happens with high res enabled when the timer was
- * already expired and the callback mode is
- * HRTIMER_CB_IRQSAFE_UNLOCKED (hrtimer_sleeper). The
- * enqueue code does not move them to the soft irq
- * pending list for performance/latency reasons, but
- * in the migration state, we need to do that
- * otherwise we end up with a stale timer.
- */
- if (timer->state == HRTIMER_STATE_MIGRATE) {
- timer->state = HRTIMER_STATE_PENDING;
- list_add_tail(&timer->cb_entry,
- &new_base->cpu_base->cb_pending);
- raise = 1;
- }
-#endif
/* Clear the migration state bit */
timer->state &= ~HRTIMER_STATE_MIGRATE;
}
- return raise;
-}
-
-#ifdef CONFIG_HIGH_RES_TIMERS
-static int migrate_hrtimer_pending(struct hrtimer_cpu_base *old_base,
- struct hrtimer_cpu_base *new_base)
-{
- struct hrtimer *timer;
- int raise = 0;
-
- while (!list_empty(&old_base->cb_pending)) {
- timer = list_entry(old_base->cb_pending.next,
- struct hrtimer, cb_entry);
-
- __remove_hrtimer(timer, timer->base, HRTIMER_STATE_PENDING, 0);
- timer->base = &new_base->clock_base[timer->base->index];
- list_add_tail(&timer->cb_entry, &new_base->cb_pending);
- raise = 1;
- }
- return raise;
-}
-#else
-static int migrate_hrtimer_pending(struct hrtimer_cpu_base *old_base,
- struct hrtimer_cpu_base *new_base)
-{
- return 0;
}
-#endif
-static void migrate_hrtimers(int cpu)
+static int migrate_hrtimers(int scpu)
{
struct hrtimer_cpu_base *old_base, *new_base;
- int i, raise = 0;
+ int dcpu, i;
- BUG_ON(cpu_online(cpu));
- old_base = &per_cpu(hrtimer_bases, cpu);
+ BUG_ON(cpu_online(scpu));
+ old_base = &per_cpu(hrtimer_bases, scpu);
new_base = &get_cpu_var(hrtimer_bases);
- tick_cancel_sched_timer(cpu);
+ dcpu = smp_processor_id();
+
+ tick_cancel_sched_timer(scpu);
/*
* The caller is globally serialized and nobody else
* takes two locks at once, deadlock is not possible.
@@ -1764,41 +1550,47 @@ static void migrate_hrtimers(int cpu)
spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);
for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
- if (migrate_hrtimer_list(&old_base->clock_base[i],
- &new_base->clock_base[i], cpu))
- raise = 1;
+ migrate_hrtimer_list(&old_base->clock_base[i],
+ &new_base->clock_base[i]);
}
- if (migrate_hrtimer_pending(old_base, new_base))
- raise = 1;
-
spin_unlock(&old_base->lock);
spin_unlock_irq(&new_base->lock);
put_cpu_var(hrtimer_bases);
- if (raise)
- hrtimer_raise_softirq();
+ return dcpu;
+}
+
+static void tickle_timers(void *arg)
+{
+ hrtimer_peek_ahead_timers();
}
+
#endif /* CONFIG_HOTPLUG_CPU */
static int __cpuinit hrtimer_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
{
- unsigned int cpu = (long)hcpu;
+ int scpu = (long)hcpu;
switch (action) {
case CPU_UP_PREPARE:
case CPU_UP_PREPARE_FROZEN:
- init_hrtimers_cpu(cpu);
+ init_hrtimers_cpu(scpu);
break;
#ifdef CONFIG_HOTPLUG_CPU
case CPU_DEAD:
case CPU_DEAD_FROZEN:
- clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DEAD, &cpu);
- migrate_hrtimers(cpu);
+ {
+ int dcpu;
+
+ clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DEAD, &scpu);
+ dcpu = migrate_hrtimers(scpu);
+ smp_call_function_single(dcpu, tickle_timers, NULL, 0);
break;
+ }
#endif
default:
@@ -1817,9 +1609,6 @@ void __init hrtimers_init(void)
hrtimer_cpu_notify(&hrtimers_nb, (unsigned long)CPU_UP_PREPARE,
(void *)(long)smp_processor_id());
register_cpu_notifier(&hrtimers_nb);
-#ifdef CONFIG_HIGH_RES_TIMERS
- open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq);
-#endif
}
/**
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index a140e44..887c637 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -116,7 +116,7 @@ static DEFINE_SPINLOCK(idr_lock);
* must supply functions here, even if the function just returns
* ENOSYS. The standard POSIX timer management code assumes the
* following: 1.) The k_itimer struct (sched.h) is used for the
- * timer. 2.) The list, it_lock, it_clock, it_id and it_process
+ * timer. 2.) The list, it_lock, it_clock, it_id and it_pid
* fields are not modified by timer code.
*
* At this time all functions EXCEPT clock_nanosleep can be
@@ -319,7 +319,8 @@ void do_schedule_next_timer(struct siginfo *info)
int posix_timer_event(struct k_itimer *timr, int si_private)
{
- int shared, ret;
+ struct task_struct *task;
+ int shared, ret = -1;
/*
* FIXME: if ->sigq is queued we can race with
* dequeue_signal()->do_schedule_next_timer().
@@ -333,8 +334,13 @@ int posix_timer_event(struct k_itimer *timr, int si_private)
*/
timr->sigq->info.si_sys_private = si_private;
- shared = !(timr->it_sigev_notify & SIGEV_THREAD_ID);
- ret = send_sigqueue(timr->sigq, timr->it_process, shared);
+ rcu_read_lock();
+ task = pid_task(timr->it_pid, PIDTYPE_PID);
+ if (task) {
+ shared = !(timr->it_sigev_notify & SIGEV_THREAD_ID);
+ ret = send_sigqueue(timr->sigq, task, shared);
+ }
+ rcu_read_unlock();
/* If we failed to send the signal the timer stops. */
return ret > 0;
}
@@ -411,7 +417,7 @@ static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer)
return ret;
}
-static struct task_struct * good_sigevent(sigevent_t * event)
+static struct pid *good_sigevent(sigevent_t * event)
{
struct task_struct *rtn = current->group_leader;
@@ -425,7 +431,7 @@ static struct task_struct * good_sigevent(sigevent_t * event)
((event->sigev_signo <= 0) || (event->sigev_signo > SIGRTMAX)))
return NULL;
- return rtn;
+ return task_pid(rtn);
}
void register_posix_clock(const clockid_t clock_id, struct k_clock *new_clock)
@@ -464,6 +470,7 @@ static void release_posix_timer(struct k_itimer *tmr, int it_id_set)
idr_remove(&posix_timers_id, tmr->it_id);
spin_unlock_irqrestore(&idr_lock, flags);
}
+ put_pid(tmr->it_pid);
sigqueue_free(tmr->sigq);
kmem_cache_free(posix_timers_cache, tmr);
}
@@ -477,7 +484,6 @@ sys_timer_create(const clockid_t which_clock,
{
struct k_itimer *new_timer;
int error, new_timer_id;
- struct task_struct *process;
sigevent_t event;
int it_id_set = IT_ID_NOT_SET;
@@ -531,11 +537,9 @@ sys_timer_create(const clockid_t which_clock,
goto out;
}
rcu_read_lock();
- process = good_sigevent(&event);
- if (process)
- get_task_struct(process);
+ new_timer->it_pid = get_pid(good_sigevent(&event));
rcu_read_unlock();
- if (!process) {
+ if (!new_timer->it_pid) {
error = -EINVAL;
goto out;
}
@@ -543,8 +547,7 @@ sys_timer_create(const clockid_t which_clock,
event.sigev_notify = SIGEV_SIGNAL;
event.sigev_signo = SIGALRM;
event.sigev_value.sival_int = new_timer->it_id;
- process = current->group_leader;
- get_task_struct(process);
+ new_timer->it_pid = get_pid(task_tgid(current));
}
new_timer->it_sigev_notify = event.sigev_notify;
@@ -554,7 +557,7 @@ sys_timer_create(const clockid_t which_clock,
new_timer->sigq->info.si_code = SI_TIMER;
spin_lock_irq(¤t->sighand->siglock);
- new_timer->it_process = process;
+ new_timer->it_signal = current->signal;
list_add(&new_timer->list, ¤t->signal->posix_timers);
spin_unlock_irq(¤t->sighand->siglock);
@@ -589,8 +592,7 @@ static struct k_itimer *lock_timer(timer_t timer_id, unsigned long *flags)
timr = idr_find(&posix_timers_id, (int)timer_id);
if (timr) {
spin_lock(&timr->it_lock);
- if (timr->it_process &&
- same_thread_group(timr->it_process, current)) {
+ if (timr->it_signal == current->signal) {
spin_unlock(&idr_lock);
return timr;
}
@@ -837,8 +839,7 @@ retry_delete:
* This keeps any tasks waiting on the spin lock from thinking
* they got something (see the lock code above).
*/
- put_task_struct(timer->it_process);
- timer->it_process = NULL;
+ timer->it_signal = NULL;
unlock_timer(timer, flags);
release_posix_timer(timer, IT_ID_SET);
@@ -864,8 +865,7 @@ retry_delete:
* This keeps any tasks waiting on the spin lock from thinking
* they got something (see the lock code above).
*/
- put_task_struct(timer->it_process);
- timer->it_process = NULL;
+ timer->it_signal = NULL;
unlock_timer(timer, flags);
release_posix_timer(timer, IT_ID_SET);
diff --git a/kernel/sched.c b/kernel/sched.c
index e4bb1dd..22c532a 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -203,7 +203,6 @@ void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime)
hrtimer_init(&rt_b->rt_period_timer,
CLOCK_MONOTONIC, HRTIMER_MODE_REL);
rt_b->rt_period_timer.function = sched_rt_period_timer;
- rt_b->rt_period_timer.cb_mode = HRTIMER_CB_IRQSAFE_UNLOCKED;
}
static inline int rt_bandwidth_enabled(void)
@@ -1139,7 +1138,6 @@ static void init_rq_hrtick(struct rq *rq)
hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
rq->hrtick_timer.function = hrtick;
- rq->hrtick_timer.cb_mode = HRTIMER_CB_IRQSAFE_PERCPU;
}
#else /* CONFIG_SCHED_HRTICK */
static inline void hrtick_clear(struct rq *rq)
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 8ff15e5..f5f793d 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -131,7 +131,7 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
{
enum hrtimer_restart res = HRTIMER_NORESTART;
- write_seqlock_irq(&xtime_lock);
+ write_seqlock(&xtime_lock);
switch (time_state) {
case TIME_OK:
@@ -164,7 +164,7 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
}
update_vsyscall(&xtime, clock);
- write_sequnlock_irq(&xtime_lock);
+ write_sequnlock(&xtime_lock);
return res;
}
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 342fc9c..8f3fc25 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -247,7 +247,7 @@ void tick_nohz_stop_sched_tick(int inidle)
if (need_resched())
goto end;
- if (unlikely(local_softirq_pending())) {
+ if (unlikely(local_softirq_pending() && cpu_online(cpu))) {
static int ratelimit;
if (ratelimit < 10) {
@@ -282,8 +282,31 @@ void tick_nohz_stop_sched_tick(int inidle)
/* Schedule the tick, if we are at least one jiffie off */
if ((long)delta_jiffies >= 1) {
+ /*
+ * calculate the expiry time for the next timer wheel
+ * timer
+ */
+ expires = ktime_add_ns(last_update, tick_period.tv64 *
+ delta_jiffies);
+
+ /*
+ * If this cpu is the one which updates jiffies, then
+ * give up the assignment and let it be taken by the
+ * cpu which runs the tick timer next, which might be
+ * this cpu as well. If we don't drop this here the
+ * jiffies might be stale and do_timer() never
+ * invoked.
+ */
+ if (cpu == tick_do_timer_cpu)
+ tick_do_timer_cpu = TICK_DO_TIMER_NONE;
+
if (delta_jiffies > 1)
cpu_set(cpu, nohz_cpu_mask);
+
+ /* Skip reprogram of event if its not changed */
+ if (ts->tick_stopped && ktime_equal(expires, dev->next_event))
+ goto out;
+
/*
* nohz_stop_sched_tick can be called several times before
* the nohz_restart_sched_tick is called. This happens when
@@ -306,17 +329,6 @@ void tick_nohz_stop_sched_tick(int inidle)
rcu_enter_nohz();
}
- /*
- * If this cpu is the one which updates jiffies, then
- * give up the assignment and let it be taken by the
- * cpu which runs the tick timer next, which might be
- * this cpu as well. If we don't drop this here the
- * jiffies might be stale and do_timer() never
- * invoked.
- */
- if (cpu == tick_do_timer_cpu)
- tick_do_timer_cpu = TICK_DO_TIMER_NONE;
-
ts->idle_sleeps++;
/*
@@ -332,12 +344,7 @@ void tick_nohz_stop_sched_tick(int inidle)
goto out;
}
- /*
- * calculate the expiry time for the next timer wheel
- * timer
- */
- expires = ktime_add_ns(last_update, tick_period.tv64 *
- delta_jiffies);
+ /* Mark expiries */
ts->idle_expires = expires;
if (ts->nohz_mode == NOHZ_MODE_HIGHRES) {
@@ -681,7 +688,6 @@ void tick_setup_sched_timer(void)
*/
hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
ts->sched_timer.function = tick_sched_timer;
- ts->sched_timer.cb_mode = HRTIMER_CB_IRQSAFE_PERCPU;
/* Get the next period (per cpu) */
hrtimer_set_expires(&ts->sched_timer, tick_init_jiffy_update());
diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c
index 9587d3b..ae542e2 100644
--- a/kernel/trace/trace_sysprof.c
+++ b/kernel/trace/trace_sysprof.c
@@ -202,7 +202,6 @@ static void start_stack_timer(int cpu)
hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
hrtimer->function = stack_trace_timer_fn;
- hrtimer->cb_mode = HRTIMER_CB_IRQSAFE_PERCPU;
hrtimer_start(hrtimer, ns_to_ktime(sample_period), HRTIMER_MODE_REL);
}
diff --git a/sound/drivers/pcsp/pcsp.c b/sound/drivers/pcsp/pcsp.c
index 1899cf0..8e52b2a 100644
--- a/sound/drivers/pcsp/pcsp.c
+++ b/sound/drivers/pcsp/pcsp.c
@@ -96,7 +96,6 @@ static int __devinit snd_card_pcsp_probe(int devnum, struct device *dev)
return -EINVAL;
hrtimer_init(&pcsp_chip.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
- pcsp_chip.timer.cb_mode = HRTIMER_CB_SOFTIRQ;
pcsp_chip.timer.function = pcsp_do_timer;
card = snd_card_new(index, id, THIS_MODULE, 0);
--
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