[PATCH 3/8] cpumask: convert kernel time functions

Mike Travis
2008-12-19T16:03:32Z

[-- Attachment #1: cpumask:convert-kernel_time.patch --]
[-- Type: text/plain, Size: 14212 bytes --]

Impact: Reduce stack usage, use new cpumask API.

Convert kernel/time functions to use struct cpumask *.

Note the ugly bitmap declarations in tick-broadcast.c. These should
be cpumask_var_t, but there was no obvious initialization function to
put the alloc_cpumask_var() calls in. This was safe.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
---
include/linux/tick.h | 4 -
kernel/time/clocksource.c | 9 +--
kernel/time/tick-broadcast.c | 115 ++++++++++++++++++++++---------------------
kernel/time/tick-common.c | 6 +-
4 files changed, 69 insertions(+), 65 deletions(-)

--- linux-2.6-for-ingo.orig/include/linux/tick.h
+++ linux-2.6-for-ingo/include/linux/tick.h
@@ -84,10 +84,10 @@ static inline void tick_cancel_sched_tim

# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
extern struct tick_device *tick_get_broadcast_device(void);
-extern cpumask_t *tick_get_broadcast_mask(void);
+extern struct cpumask *tick_get_broadcast_mask(void);

# ifdef CONFIG_TICK_ONESHOT
-extern cpumask_t *tick_get_broadcast_oneshot_mask(void);
+extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
# endif

# endif /* BROADCAST */
--- linux-2.6-for-ingo.orig/kernel/time/clocksource.c
+++ linux-2.6-for-ingo/kernel/time/clocksource.c
@@ -145,10 +145,11 @@ static void clocksource_watchdog(unsigne
* Cycle through CPUs to check if the CPUs stay
* synchronized to each other.
*/
- int next_cpu = next_cpu_nr(raw_smp_processor_id(), cpu_online_map);
+ int next_cpu = cpumask_next(raw_smp_processor_id(),
+ cpu_online_mask);

if (next_cpu >= nr_cpu_ids)
- next_cpu = first_cpu(cpu_online_map);
+ next_cpu = cpumask_first(cpu_online_mask);
watchdog_timer.expires += WATCHDOG_INTERVAL;
add_timer_on(&watchdog_timer, next_cpu);
}
@@ -173,7 +174,7 @@ static void clocksource_check_watchdog(s
watchdog_last = watchdog->read();
watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL;
add_timer_on(&watchdog_timer,
- first_cpu(cpu_online_map));
+ cpumask_first(cpu_online_mask));
}
} else {
if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS)
@@ -195,7 +196,7 @@ static void clocksource_check_watchdog(s
watchdog_timer.expires =
jiffies + WATCHDOG_INTERVAL;
add_timer_on(&watchdog_timer,
- first_cpu(cpu_online_map));
+ cpumask_first(cpu_online_mask));
}
}
}
--- linux-2.6-for-ingo.orig/kernel/time/tick-broadcast.c
+++ linux-2.6-for-ingo/kernel/time/tick-broadcast.c
@@ -28,7 +28,9 @@
*/

struct tick_device tick_broadcast_device;
-static cpumask_t tick_broadcast_mask;
+/* FIXME: Use cpumask_var_t. */
+static DECLARE_BITMAP(tick_broadcast_mask, CONFIG_NR_CPUS);
+static DECLARE_BITMAP(tmpmask, CONFIG_NR_CPUS);
static DEFINE_SPINLOCK(tick_broadcast_lock);
static int tick_broadcast_force;

@@ -46,9 +48,9 @@ struct tick_device *tick_get_broadcast_d
return &tick_broadcast_device;
}

-cpumask_t *tick_get_broadcast_mask(void)
+struct cpumask *tick_get_broadcast_mask(void)
{
- return &tick_broadcast_mask;
+ return to_cpumask(tick_broadcast_mask);
}

/*
@@ -72,7 +74,7 @@ int tick_check_broadcast_device(struct c

clockevents_exchange_device(NULL, dev);
tick_broadcast_device.evtdev = dev;
- if (!cpus_empty(tick_broadcast_mask))
+ if (!cpumask_empty(tick_get_broadcast_mask()))
tick_broadcast_start_periodic(dev);
return 1;
}
@@ -104,7 +106,7 @@ int tick_device_uses_broadcast(struct cl
*/
if (!tick_device_is_functional(dev)) {
dev->event_handler = tick_handle_periodic;
- cpu_set(cpu, tick_broadcast_mask);
+ cpumask_set_cpu(cpu, tick_get_broadcast_mask());
tick_broadcast_start_periodic(tick_broadcast_device.evtdev);
ret = 1;
} else {
@@ -116,7 +118,7 @@ int tick_device_uses_broadcast(struct cl
if (!(dev->features & CLOCK_EVT_FEAT_C3STOP)) {
int cpu = smp_processor_id();

- cpu_clear(cpu, tick_broadcast_mask);
+ cpumask_clear_cpu(cpu, tick_get_broadcast_mask());
tick_broadcast_clear_oneshot(cpu);
}
}
@@ -125,9 +127,9 @@ int tick_device_uses_broadcast(struct cl
}

/*
- * Broadcast the event to the cpus, which are set in the mask
+ * Broadcast the event to the cpus, which are set in the mask (mangled).
*/
-static void tick_do_broadcast(cpumask_t mask)
+static void tick_do_broadcast(struct cpumask *mask)
{
int cpu = smp_processor_id();
struct tick_device *td;
@@ -135,22 +137,21 @@ static void tick_do_broadcast(cpumask_t
/*
* Check, if the current cpu is in the mask
*/
- if (cpu_isset(cpu, mask)) {
- cpu_clear(cpu, mask);
+ if (cpumask_test_cpu(cpu, mask)) {
+ cpumask_clear_cpu(cpu, mask);
td = &per_cpu(tick_cpu_device, cpu);
td->evtdev->event_handler(td->evtdev);
}

- if (!cpus_empty(mask)) {
+ if (!cpumask_empty(mask)) {
/*
* It might be necessary to actually check whether the devices
* have different broadcast functions. For now, just use the
* one of the first device. This works as long as we have this
* misfeature only on x86 (lapic)
*/
- cpu = first_cpu(mask);
- td = &per_cpu(tick_cpu_device, cpu);
- td->evtdev->broadcast(&mask);
+ td = &per_cpu(tick_cpu_device, cpumask_first(mask));
+ td->evtdev->broadcast(mask);
}
}

@@ -160,12 +161,11 @@ static void tick_do_broadcast(cpumask_t
*/
static void tick_do_periodic_broadcast(void)
{
- cpumask_t mask;
-
spin_lock(&tick_broadcast_lock);

- cpus_and(mask, cpu_online_map, tick_broadcast_mask);
- tick_do_broadcast(mask);
+ cpumask_and(to_cpumask(tmpmask),
+ cpu_online_mask, tick_get_broadcast_mask());
+ tick_do_broadcast(to_cpumask(tmpmask));

spin_unlock(&tick_broadcast_lock);
}
@@ -228,13 +228,13 @@ static void tick_do_broadcast_on_off(voi
if (!tick_device_is_functional(dev))
goto out;

- bc_stopped = cpus_empty(tick_broadcast_mask);
+ bc_stopped = cpumask_empty(tick_get_broadcast_mask());

switch (*reason) {
case CLOCK_EVT_NOTIFY_BROADCAST_ON:
case CLOCK_EVT_NOTIFY_BROADCAST_FORCE:
- if (!cpu_isset(cpu, tick_broadcast_mask)) {
- cpu_set(cpu, tick_broadcast_mask);
+ if (!cpumask_test_cpu(cpu, tick_get_broadcast_mask())) {
+ cpumask_set_cpu(cpu, tick_get_broadcast_mask());
if (tick_broadcast_device.mode ==
TICKDEV_MODE_PERIODIC)
clockevents_shutdown(dev);
@@ -244,8 +244,8 @@ static void tick_do_broadcast_on_off(voi
break;
case CLOCK_EVT_NOTIFY_BROADCAST_OFF:
if (!tick_broadcast_force &&
- cpu_isset(cpu, tick_broadcast_mask)) {
- cpu_clear(cpu, tick_broadcast_mask);
+ cpumask_test_cpu(cpu, tick_get_broadcast_mask())) {
+ cpumask_clear_cpu(cpu, tick_get_broadcast_mask());
if (tick_broadcast_device.mode ==
TICKDEV_MODE_PERIODIC)
tick_setup_periodic(dev, 0);
@@ -253,7 +253,7 @@ static void tick_do_broadcast_on_off(voi
break;
}

- if (cpus_empty(tick_broadcast_mask)) {
+ if (cpumask_empty(tick_get_broadcast_mask())) {
if (!bc_stopped)
clockevents_shutdown(bc);
} else if (bc_stopped) {
@@ -272,7 +272,7 @@ out:
*/
void tick_broadcast_on_off(unsigned long reason, int *oncpu)
{
- if (!cpu_isset(*oncpu, cpu_online_map))
+ if (!cpumask_test_cpu(*oncpu, cpu_online_mask))
printk(KERN_ERR "tick-broadcast: ignoring broadcast for "
"offline CPU #%d\n", *oncpu);
else
@@ -303,10 +303,10 @@ void tick_shutdown_broadcast(unsigned in
spin_lock_irqsave(&tick_broadcast_lock, flags);

bc = tick_broadcast_device.evtdev;
- cpu_clear(cpu, tick_broadcast_mask);
+ cpumask_clear_cpu(cpu, tick_get_broadcast_mask());

if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) {
- if (bc && cpus_empty(tick_broadcast_mask))
+ if (bc && cpumask_empty(tick_get_broadcast_mask()))
clockevents_shutdown(bc);
}

@@ -342,10 +342,10 @@ int tick_resume_broadcast(void)

switch (tick_broadcast_device.mode) {
case TICKDEV_MODE_PERIODIC:
- if(!cpus_empty(tick_broadcast_mask))
+ if (!cpumask_empty(tick_get_broadcast_mask()))
tick_broadcast_start_periodic(bc);
- broadcast = cpu_isset(smp_processor_id(),
- tick_broadcast_mask);
+ broadcast = cpumask_test_cpu(smp_processor_id(),
+ tick_get_broadcast_mask());
break;
case TICKDEV_MODE_ONESHOT:
broadcast = tick_resume_broadcast_oneshot(bc);
@@ -360,14 +360,15 @@ int tick_resume_broadcast(void)

#ifdef CONFIG_TICK_ONESHOT

-static cpumask_t tick_broadcast_oneshot_mask;
+/* FIXME: use cpumask_var_t. */
+static DECLARE_BITMAP(tick_broadcast_oneshot_mask, CONFIG_NR_CPUS);

/*
- * Debugging: see timer_list.c
+ * Exposed for debugging: see timer_list.c
*/
-cpumask_t *tick_get_broadcast_oneshot_mask(void)
+struct cpumask *tick_get_broadcast_oneshot_mask(void)
{
- return &tick_broadcast_oneshot_mask;
+ return to_cpumask(tick_broadcast_oneshot_mask);
}

static int tick_broadcast_set_event(ktime_t expires, int force)
@@ -389,7 +390,7 @@ int tick_resume_broadcast_oneshot(struct
*/
void tick_check_oneshot_broadcast(int cpu)
{
- if (cpu_isset(cpu, tick_broadcast_oneshot_mask)) {
+ if (cpumask_test_cpu(cpu, to_cpumask(tick_broadcast_oneshot_mask))) {
struct tick_device *td = &per_cpu(tick_cpu_device, cpu);

clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_ONESHOT);
@@ -402,7 +403,6 @@ void tick_check_oneshot_broadcast(int cp
static void tick_handle_oneshot_broadcast(struct clock_event_device *dev)
{
struct tick_device *td;
- cpumask_t mask;
ktime_t now, next_event;
int cpu;

@@ -410,13 +410,13 @@ static void tick_handle_oneshot_broadcas
again:
dev->next_event.tv64 = KTIME_MAX;
next_event.tv64 = KTIME_MAX;
- mask = CPU_MASK_NONE;
+ cpumask_clear(to_cpumask(tmpmask));
now = ktime_get();
/* Find all expired events */
- for_each_cpu_mask_nr(cpu, tick_broadcast_oneshot_mask) {
+ for_each_cpu(cpu, tick_get_broadcast_oneshot_mask()) {
td = &per_cpu(tick_cpu_device, cpu);
if (td->evtdev->next_event.tv64 <= now.tv64)
- cpu_set(cpu, mask);
+ cpumask_set_cpu(cpu, to_cpumask(tmpmask));
else if (td->evtdev->next_event.tv64 < next_event.tv64)
next_event.tv64 = td->evtdev->next_event.tv64;
}
@@ -424,7 +424,7 @@ again:
/*
* Wakeup the cpus which have an expired event.
*/
- tick_do_broadcast(mask);
+ tick_do_broadcast(to_cpumask(tmpmask));

/*
* Two reasons for reprogram:
@@ -476,15 +476,16 @@ void tick_broadcast_oneshot_control(unsi
goto out;

if (reason == CLOCK_EVT_NOTIFY_BROADCAST_ENTER) {
- if (!cpu_isset(cpu, tick_broadcast_oneshot_mask)) {
- cpu_set(cpu, tick_broadcast_oneshot_mask);
+ if (!cpumask_test_cpu(cpu, tick_get_broadcast_oneshot_mask())) {
+ cpumask_set_cpu(cpu, tick_get_broadcast_oneshot_mask());
clockevents_set_mode(dev, CLOCK_EVT_MODE_SHUTDOWN);
if (dev->next_event.tv64 < bc->next_event.tv64)
tick_broadcast_set_event(dev->next_event, 1);
}
} else {
- if (cpu_isset(cpu, tick_broadcast_oneshot_mask)) {
- cpu_clear(cpu, tick_broadcast_oneshot_mask);
+ if (cpumask_test_cpu(cpu, tick_get_broadcast_oneshot_mask())) {
+ cpumask_clear_cpu(cpu,
+ tick_get_broadcast_oneshot_mask());
clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT);
if (dev->next_event.tv64 != KTIME_MAX)
tick_program_event(dev->next_event, 1);
@@ -502,15 +503,16 @@ out:
*/
static void tick_broadcast_clear_oneshot(int cpu)
{
- cpu_clear(cpu, tick_broadcast_oneshot_mask);
+ cpumask_clear_cpu(cpu, tick_get_broadcast_oneshot_mask());
}

-static void tick_broadcast_init_next_event(cpumask_t *mask, ktime_t expires)
+static void tick_broadcast_init_next_event(struct cpumask *mask,
+ ktime_t expires)
{
struct tick_device *td;
int cpu;

- for_each_cpu_mask_nr(cpu, *mask) {
+ for_each_cpu(cpu, mask) {
td = &per_cpu(tick_cpu_device, cpu);
if (td->evtdev)
td->evtdev->next_event = expires;
@@ -526,7 +528,6 @@ void tick_broadcast_setup_oneshot(struct
if (bc->event_handler != tick_handle_oneshot_broadcast) {
int was_periodic = bc->mode == CLOCK_EVT_MODE_PERIODIC;
int cpu = smp_processor_id();
- cpumask_t mask;

bc->event_handler = tick_handle_oneshot_broadcast;
clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT);
@@ -540,13 +541,15 @@ void tick_broadcast_setup_oneshot(struct
* oneshot_mask bits for those and program the
* broadcast device to fire.
*/
- mask = tick_broadcast_mask;
- cpu_clear(cpu, mask);
- cpus_or(tick_broadcast_oneshot_mask,
- tick_broadcast_oneshot_mask, mask);
-
- if (was_periodic && !cpus_empty(mask)) {
- tick_broadcast_init_next_event(&mask, tick_next_period);
+ cpumask_copy(to_cpumask(tmpmask), tick_get_broadcast_mask());
+ cpumask_clear_cpu(cpu, to_cpumask(tmpmask));
+ cpumask_or(tick_get_broadcast_oneshot_mask(),
+ tick_get_broadcast_oneshot_mask(),
+ to_cpumask(tmpmask));
+
+ if (was_periodic && !cpumask_empty(to_cpumask(tmpmask))) {
+ tick_broadcast_init_next_event(to_cpumask(tmpmask),
+ tick_next_period);
tick_broadcast_set_event(tick_next_period, 1);
} else
bc->next_event.tv64 = KTIME_MAX;
@@ -585,7 +588,7 @@ void tick_shutdown_broadcast_oneshot(uns
* Clear the broadcast mask flag for the dead cpu, but do not
* stop the broadcast device!
*/
- cpu_clear(cpu, tick_broadcast_oneshot_mask);
+ cpumask_clear_cpu(cpu, tick_get_broadcast_oneshot_mask());

spin_unlock_irqrestore(&tick_broadcast_lock, flags);
}
--- linux-2.6-for-ingo.orig/kernel/time/tick-common.c
+++ linux-2.6-for-ingo/kernel/time/tick-common.c
@@ -254,7 +254,7 @@ static int tick_check_new_device(struct
curdev = NULL;
}
clockevents_exchange_device(curdev, newdev);
- tick_setup_device(td, newdev, cpu, &cpumask_of_cpu(cpu));
+ tick_setup_device(td, newdev, cpu, cpumask_of(cpu));
if (newdev->features & CLOCK_EVT_FEAT_ONESHOT)
tick_oneshot_notify();

@@ -299,9 +299,9 @@ static void tick_shutdown(unsigned int *
}
/* Transfer the do_timer job away from this cpu */
if (*cpup == tick_do_timer_cpu) {
- int cpu = first_cpu(cpu_online_map);
+ int cpu = cpumask_first(cpu_online_mask);

- tick_do_timer_cpu = (cpu != NR_CPUS) ? cpu :
+ tick_do_timer_cpu = (cpu < nr_cpu_ids) ? cpu :
TICK_DO_TIMER_NONE;
}
spin_unlock_irqrestore(&tick_device_lock, flags);

--