Re: [PATCH 3/3] hrtimer: Use for_each_active_base() to iterate over active clock bases

On 06/09/2014 09:38 PM, Viresh Kumar wrote:

At several instances we iterate over all possible clock-bases for a particular cpu-base. Whereas, we only need to iterate over active bases.

We already have for_each_active_base() now, which can be used at these places to generate more efficient code.

This patch updates all possible sites which were iterating over all possible clock-bases.

Signed-off-by: Viresh Kumar viresh.kumar@linaro.org

kernel/hrtimer.c | 56 ++++++++++++++++++++++---------------------------------- 1 file changed, 22 insertions(+), 34 deletions(-)

diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 3aae27a..4dec883 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -556,20 +556,16 @@ static void hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base, int skip_equal) { int i;

• struct hrtimer_clock_base *base = cpu_base->clock_base;

• struct hrtimer_clock_base *base;

• struct hrtimer *timer; ktime_t expires, expires_next;

• unsigned int active_bases;

  expires_next.tv64 = KTIME_MAX;

• for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {

• struct hrtimer *timer;
  

• struct timerqueue_node *next;
  

• next = timerqueue_getnext(&base->active);
  

• if (!next)
  

• 	continue;
  

• timer = container_of(next, struct hrtimer, node);
  

• for_each_active_base(i, base, cpu_base, active_bases) {

• timer = container_of(timerqueue_getnext(&base->active),
  

• 		     struct hrtimer, node);
  

  expires = ktime_sub(hrtimer_get_expires(timer), base->offset); /*
  • clock_was_set() has changed base->offset so the

@@ -1168,23 +1164,19 @@ EXPORT_SYMBOL_GPL(hrtimer_get_remaining); ktime_t hrtimer_get_next_event(void) { struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);

• struct hrtimer_clock_base *base = cpu_base->clock_base;

• struct hrtimer_clock_base *base; ktime_t delta, mindelta = { .tv64 = KTIME_MAX };

• struct hrtimer *timer;

• unsigned int active_bases; unsigned long flags; int i;

  raw_spin_lock_irqsave(&cpu_base->lock, flags);

  if (!hrtimer_hres_active()) {

• for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
  

• 	struct hrtimer *timer;
  

• 	struct timerqueue_node *next;
  

• 	next = timerqueue_getnext(&base->active);
  

• 	if (!next)
  

• 		continue;
  

• 	timer = container_of(next, struct hrtimer, node);
  

• for_each_active_base(i, base, cpu_base, active_bases) {
  

• 	timer = container_of(timerqueue_getnext(&base->active),
  

• 			     struct hrtimer, node);
  delta.tv64 = hrtimer_get_expires_tv64(timer);
  delta = ktime_sub(delta, base->get_time());
  if (delta.tv64 < mindelta.tv64)
  

@@ -1307,7 +1299,9 @@ static void __run_hrtimer(struct hrtimer *timer, ktime_t *now) 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, entry_time, delta;

• unsigned int active_bases; int i, retries = 0;

  BUG_ON(!cpu_base->hres_active);

@@ -1327,15 +1321,10 @@ retry: */ cpu_base->expires_next.tv64 = KTIME_MAX;

• for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {

• struct hrtimer_clock_base *base;
  

• for_each_active_base(i, base, cpu_base, active_bases) { struct timerqueue_node *node; ktime_t basenow;

• if (!(cpu_base->active_bases & (1 << i)))
  

• 	continue;
  

• base = cpu_base->clock_base + i;
  

  basenow = ktime_add(now, base->offset);

  while ((node = timerqueue_getnext(&base->active))) {

@@ -1506,16 +1495,13 @@ void hrtimer_run_queues(void) struct timerqueue_node *node; struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); struct hrtimer_clock_base *base;

• unsigned int active_bases; int index, gettime = 1;

  if (hrtimer_hres_active()) return;

• for (index = 0; index < HRTIMER_MAX_CLOCK_BASES; index++) {

• base = &cpu_base->clock_base[index];
  

• if (!timerqueue_getnext(&base->active))
  

• 	continue;
  

• for_each_active_base(index, base, cpu_base, active_bases) { if (gettime) { hrtimer_get_softirq_time(cpu_base); gettime = 0;

@@ -1735,6 +1721,8 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base, static void migrate_hrtimers(int scpu) { struct hrtimer_cpu_base *old_base, *new_base;

• struct hrtimer_clock_base *clock_base;

• unsigned int active_bases; int i;

  BUG_ON(cpu_online(scpu));

@@ -1750,9 +1738,9 @@ static void migrate_hrtimers(int scpu) raw_spin_lock(&new_base->lock); raw_spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);

• for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {

• migrate_hrtimer_list(&old_base->clock_base[i],
  

• 		     &new_base->clock_base[i]);
  

• for_each_active_base(i, clock_base, old_base, active_bases) {

• migrate_hrtimer_list(clock_base,
  

• 		     &new_base->clock_base[clock_base->index]);
  

  }

  raw_spin_unlock(&old_base->lock);

Reviewed-by: Preeti U Murthy preeti@linux.vnet.ibm.com