1 files changed, 59 insertions, 86 deletions

diff --git a/kernel/timer.c b/kernel/timer.c
index cffffad01c31..a7f07d5a6241 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -37,6 +37,8 @@
 #include <linux/delay.h>
 #include <linux/tick.h>
 #include <linux/kallsyms.h>
+#include <linux/perf_counter.h>
+#include <linux/sched.h>
 
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
@@ -378,6 +380,8 @@ static void timer_stats_account_timer(struct timer_list *timer)
 {
         unsigned int flag = 0;
 
+        if (likely(!timer->start_site))
+                return;
         if (unlikely(tbase_get_deferrable(timer->base)))
                 flag |= TIMER_STATS_FLAG_DEFERRABLE;
 
@@ -604,13 +608,12 @@ static struct tvec_base *lock_timer_base(struct timer_list *timer,
 }
 
 static inline int
-__mod_timer(struct timer_list *timer, unsigned long expires, bool pending_only)
+__mod_timer(struct timer_list *timer, unsigned long expires,
+                                                bool pending_only, int pinned)
 {
         struct tvec_base *base, *new_base;
         unsigned long flags;
-        int ret;
-
-        ret = 0;
+        int ret = 0 , cpu;
 
         timer_stats_timer_set_start_info(timer);
         BUG_ON(!timer->function);
@@ -629,6 +632,18 @@ __mod_timer(struct timer_list *timer, unsigned long expires, bool pending_only)
 
         new_base = __get_cpu_var(tvec_bases);
 
+        cpu = smp_processor_id();
+
+#if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP)
+        if (!pinned && get_sysctl_timer_migration() && idle_cpu(cpu)) {
+                int preferred_cpu = get_nohz_load_balancer();
+
+                if (preferred_cpu >= 0)
+                        cpu = preferred_cpu;
+        }
+#endif
+        new_base = per_cpu(tvec_bases, cpu);
+
         if (base != new_base) {
                 /*
                  * We are trying to schedule the timer on the local CPU.
@@ -668,7 +683,7 @@ out_unlock:
  */
 int mod_timer_pending(struct timer_list *timer, unsigned long expires)
 {
-        return __mod_timer(timer, expires, true);
+        return __mod_timer(timer, expires, true, TIMER_NOT_PINNED);
 }
 EXPORT_SYMBOL(mod_timer_pending);
 
@@ -699,14 +714,36 @@ int mod_timer(struct timer_list *timer, unsigned long expires)
          * networking code - if the timer is re-modified
          * to be the same thing then just return:
          */
-        if (timer->expires == expires && timer_pending(timer))
+        if (timer_pending(timer) && timer->expires == expires)
                 return 1;
 
-        return __mod_timer(timer, expires, false);
+        return __mod_timer(timer, expires, false, TIMER_NOT_PINNED);
 }
 EXPORT_SYMBOL(mod_timer);
 
 /**
+ * mod_timer_pinned - modify a timer's timeout
+ * @timer: the timer to be modified
+ * @expires: new timeout in jiffies
+ *
+ * mod_timer_pinned() is a way to update the expire field of an
+ * active timer (if the timer is inactive it will be activated)
+ * and not allow the timer to be migrated to a different CPU.
+ *
+ * mod_timer_pinned(timer, expires) is equivalent to:
+ *
+ *     del_timer(timer); timer->expires = expires; add_timer(timer);
+ */
+int mod_timer_pinned(struct timer_list *timer, unsigned long expires)
+{
+        if (timer->expires == expires && timer_pending(timer))
+                return 1;
+
+        return __mod_timer(timer, expires, false, TIMER_PINNED);
+}
+EXPORT_SYMBOL(mod_timer_pinned);
+
+/**
  * add_timer - start a timer
  * @timer: the timer to be added
  *
@@ -756,6 +793,7 @@ void add_timer_on(struct timer_list *timer, int cpu)
         wake_up_idle_cpu(cpu);
         spin_unlock_irqrestore(&base->lock, flags);
 }
+EXPORT_SYMBOL_GPL(add_timer_on);
 
 /**
  * del_timer - deactive a timer.
@@ -1015,6 +1053,9 @@ cascade:
                 index = slot = timer_jiffies & TVN_MASK;
                 do {
                         list_for_each_entry(nte, varp->vec + slot, entry) {
+                                if (tbase_get_deferrable(nte->base))
+                                        continue;
+
                                 found = 1;
                                 if (time_before(nte->expires, expires))
                                         expires = nte->expires;
@@ -1123,53 +1164,14 @@ void update_process_times(int user_tick)
 }
 
 /*
- * Nr of active tasks - counted in fixed-point numbers
- */
-static unsigned long count_active_tasks(void)
-{
-        return nr_active() * FIXED_1;
-}
-
-/*
- * Hmm.. Changed this, as the GNU make sources (load.c) seems to
- * imply that avenrun[] is the standard name for this kind of thing.
- * Nothing else seems to be standardized: the fractional size etc
- * all seem to differ on different machines.
- *
- * Requires xtime_lock to access.
- */
-unsigned long avenrun[3];
-
-EXPORT_SYMBOL(avenrun);
-
-/*
- * calc_load - given tick count, update the avenrun load estimates.
- * This is called while holding a write_lock on xtime_lock.
- */
-static inline void calc_load(unsigned long ticks)
-{
-        unsigned long active_tasks; /* fixed-point */
-        static int count = LOAD_FREQ;
-
-        count -= ticks;
-        if (unlikely(count < 0)) {
-                active_tasks = count_active_tasks();
-                do {
-                        CALC_LOAD(avenrun[0], EXP_1, active_tasks);
-                        CALC_LOAD(avenrun[1], EXP_5, active_tasks);
-                        CALC_LOAD(avenrun[2], EXP_15, active_tasks);
-                        count += LOAD_FREQ;
-                } while (count < 0);
-        }
-}
-
-/*
  * This function runs timers and the timer-tq in bottom half context.
  */
 static void run_timer_softirq(struct softirq_action *h)
 {
         struct tvec_base *base = __get_cpu_var(tvec_bases);
 
+        perf_counter_do_pending();
+
         hrtimer_run_pending();
 
         if (time_after_eq(jiffies, base->timer_jiffies))
@@ -1187,16 +1189,6 @@ void run_local_timers(void)
 }
 
 /*
- * Called by the timer interrupt. xtime_lock must already be taken
- * by the timer IRQ!
- */
-static inline void update_times(unsigned long ticks)
-{
-        update_wall_time();
-        calc_load(ticks);
-}
-
-/*
  * The 64-bit jiffies value is not atomic - you MUST NOT read it
  * without sampling the sequence number in xtime_lock.
  * jiffies is defined in the linker script...
@@ -1205,7 +1197,8 @@ static inline void update_times(unsigned long ticks)
 void do_timer(unsigned long ticks)
 {
         jiffies_64 += ticks;
-        update_times(ticks);
+        update_wall_time();
+        calc_global_load();
 }
 
 #ifdef __ARCH_WANT_SYS_ALARM
@@ -1353,7 +1346,7 @@ signed long __sched schedule_timeout(signed long timeout)
         expire = timeout + jiffies;
 
         setup_timer_on_stack(&timer, process_timeout, (unsigned long)current);
-        __mod_timer(&timer, expire, false);
+        __mod_timer(&timer, expire, false, TIMER_NOT_PINNED);
         schedule();
         del_singleshot_timer_sync(&timer);
 
@@ -1406,37 +1399,17 @@ int do_sysinfo(struct sysinfo *info)
 {
         unsigned long mem_total, sav_total;
         unsigned int mem_unit, bitcount;
-        unsigned long seq;
+        struct timespec tp;
 
         memset(info, 0, sizeof(struct sysinfo));
 
-        do {
-                struct timespec tp;
-                seq = read_seqbegin(&xtime_lock);
-
-                /*
-                 * This is annoying.  The below is the same thing
-                 * posix_get_clock_monotonic() does, but it wants to
-                 * take the lock which we want to cover the loads stuff
-                 * too.
-                 */
-
-                getnstimeofday(&tp);
-                tp.tv_sec += wall_to_monotonic.tv_sec;
-                tp.tv_nsec += wall_to_monotonic.tv_nsec;
-                monotonic_to_bootbased(&tp);
-                if (tp.tv_nsec - NSEC_PER_SEC >= 0) {
-                        tp.tv_nsec = tp.tv_nsec - NSEC_PER_SEC;
-                        tp.tv_sec++;
-                }
-                info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
+        ktime_get_ts(&tp);
+        monotonic_to_bootbased(&tp);
+        info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
 
-                info->loads[0] = avenrun[0] << (SI_LOAD_SHIFT - FSHIFT);
-                info->loads[1] = avenrun[1] << (SI_LOAD_SHIFT - FSHIFT);
-                info->loads[2] = avenrun[2] << (SI_LOAD_SHIFT - FSHIFT);
+        get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
 
-                info->procs = nr_threads;
-        } while (read_seqretry(&xtime_lock, seq));
+        info->procs = nr_threads;
 
         si_meminfo(info);
         si_swapinfo(info);