*/
#include <linux/kernel_stat.h>
-#include <linux/module.h>
+#include <linux/export.h>
#include <linux/interrupt.h>
#include <linux/percpu.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/tick.h>
#include <linux/kallsyms.h>
-#include <linux/perf_event.h>
+#include <linux/irq_work.h>
#include <linux/sched.h>
#include <linux/slab.h>
static struct debug_obj_descr timer_debug_descr;
+static void *timer_debug_hint(void *addr)
+{
+ return ((struct timer_list *) addr)->function;
+}
+
/*
* fixup_init is called when:
* - an active object is initialized
static struct debug_obj_descr timer_debug_descr = {
.name = "timer_list",
+ .debug_hint = timer_debug_hint,
.fixup_init = timer_fixup_init,
.fixup_activate = timer_fixup_activate,
.fixup_free = timer_fixup_free,
unsigned long expires_limit, mask;
int bit;
- expires_limit = expires;
-
if (timer->slack >= 0) {
expires_limit = expires + timer->slack;
} else {
- unsigned long now = jiffies;
+ long delta = expires - jiffies;
- /* No slack, if already expired else auto slack 0.4% */
- if (time_after(expires, now))
- expires_limit = expires + (expires - now)/256;
+ if (delta < 256)
+ return expires;
+
+ expires_limit = expires + delta / 256;
}
mask = expires ^ expires_limit;
if (mask == 0)
*/
int mod_timer(struct timer_list *timer, unsigned long expires)
{
+ expires = apply_slack(timer, expires);
+
/*
* This is a common optimization triggered by the
* networking code - if the timer is re-modified
if (timer_pending(timer) && timer->expires == expires)
return 1;
- expires = apply_slack(timer, expires);
-
return __mod_timer(timer, expires, false, TIMER_NOT_PINNED);
}
EXPORT_SYMBOL(mod_timer);
*
* Synchronization rules: Callers must prevent restarting of the timer,
* otherwise this function is meaningless. It must not be called from
- * hardirq contexts. The caller must not hold locks which would prevent
+ * interrupt contexts. The caller must not hold locks which would prevent
* completion of the timer's handler. The timer's handler must not call
* add_timer_on(). Upon exit the timer is not queued and the handler is
* not running on any CPU.
*
+ * Note: You must not hold locks that are held in interrupt context
+ * while calling this function. Even if the lock has nothing to do
+ * with the timer in question. Here's why:
+ *
+ * CPU0 CPU1
+ * ---- ----
+ * <SOFTIRQ>
+ * call_timer_fn();
+ * base->running_timer = mytimer;
+ * spin_lock_irq(somelock);
+ * <IRQ>
+ * spin_lock(somelock);
+ * del_timer_sync(mytimer);
+ * while (base->running_timer == mytimer);
+ *
+ * Now del_timer_sync() will never return and never release somelock.
+ * The interrupt on the other CPU is waiting to grab somelock but
+ * it has interrupted the softirq that CPU0 is waiting to finish.
+ *
* The function returns whether it has deactivated a pending timer or not.
*/
int del_timer_sync(struct timer_list *timer)
{
#ifdef CONFIG_LOCKDEP
- local_bh_disable();
+ unsigned long flags;
+
+ /*
+ * If lockdep gives a backtrace here, please reference
+ * the synchronization rules above.
+ */
+ local_irq_save(flags);
lock_map_acquire(&timer->lockdep_map);
lock_map_release(&timer->lockdep_map);
- local_bh_enable();
+ local_irq_restore(flags);
#endif
/*
* don't use it in hardirq context, because it
*/
unsigned long get_next_timer_interrupt(unsigned long now)
{
- struct tvec_base *base = __get_cpu_var(tvec_bases);
+ struct tvec_base *base = __this_cpu_read(tvec_bases);
unsigned long expires;
+ /*
+ * Pretend that there is no timer pending if the cpu is offline.
+ * Possible pending timers will be migrated later to an active cpu.
+ */
+ if (cpu_is_offline(smp_processor_id()))
+ return now + NEXT_TIMER_MAX_DELTA;
spin_lock(&base->lock);
if (time_before_eq(base->next_timer, base->timer_jiffies))
base->next_timer = __next_timer_interrupt(base);
run_local_timers();
rcu_check_callbacks(cpu, user_tick);
printk_tick();
- perf_event_do_pending();
+#ifdef CONFIG_IRQ_WORK
+ if (in_irq())
+ irq_work_run();
+#endif
scheduler_tick();
run_posix_cpu_timers(p);
}
*/
static void run_timer_softirq(struct softirq_action *h)
{
- struct tvec_base *base = __get_cpu_var(tvec_bases);
+ struct tvec_base *base = __this_cpu_read(tvec_bases);
hrtimer_run_pending();
raise_softirq(TIMER_SOFTIRQ);
}
-/*
- * 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...
- */
-
-void do_timer(unsigned long ticks)
-{
- jiffies_64 += ticks;
- update_wall_time();
- calc_global_load();
-}
-
#ifdef __ARCH_WANT_SYS_ALARM
/*
int pid;
rcu_read_lock();
- pid = task_tgid_vnr(current->real_parent);
+ pid = task_tgid_vnr(rcu_dereference(current->real_parent));
rcu_read_unlock();
return pid;
projects / linux-flexiantxendom0.git / blobdiff