diff options
Diffstat (limited to 'kernel/softirq.c')
| -rw-r--r-- | kernel/softirq.c | 63 |
1 files changed, 41 insertions, 22 deletions
diff --git a/kernel/softirq.c b/kernel/softirq.c index 31e9f2a47928..3c44956ee7e2 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -356,7 +356,8 @@ void open_softirq(int nr, void (*action)(struct softirq_action*), void *data) /* Tasklets */ struct tasklet_head { - struct tasklet_struct *list; + struct tasklet_struct *head; + struct tasklet_struct **tail; }; /* Some compilers disobey section attribute on statics when not @@ -369,8 +370,9 @@ void __tasklet_schedule(struct tasklet_struct *t) unsigned long flags; local_irq_save(flags); - t->next = __get_cpu_var(tasklet_vec).list; - __get_cpu_var(tasklet_vec).list = t; + t->next = NULL; + *__get_cpu_var(tasklet_vec).tail = t; + __get_cpu_var(tasklet_vec).tail = &(t->next); raise_softirq_irqoff(TASKLET_SOFTIRQ); local_irq_restore(flags); } @@ -382,8 +384,9 @@ void __tasklet_hi_schedule(struct tasklet_struct *t) unsigned long flags; local_irq_save(flags); - t->next = __get_cpu_var(tasklet_hi_vec).list; - __get_cpu_var(tasklet_hi_vec).list = t; + t->next = NULL; + *__get_cpu_var(tasklet_hi_vec).tail = t; + __get_cpu_var(tasklet_hi_vec).tail = &(t->next); raise_softirq_irqoff(HI_SOFTIRQ); local_irq_restore(flags); } @@ -395,8 +398,9 @@ static void tasklet_action(struct softirq_action *a) struct tasklet_struct *list; local_irq_disable(); - list = __get_cpu_var(tasklet_vec).list; - __get_cpu_var(tasklet_vec).list = NULL; + list = __get_cpu_var(tasklet_vec).head; + __get_cpu_var(tasklet_vec).head = NULL; + __get_cpu_var(tasklet_vec).tail = &__get_cpu_var(tasklet_vec).head; local_irq_enable(); while (list) { @@ -416,8 +420,9 @@ static void tasklet_action(struct softirq_action *a) } local_irq_disable(); - t->next = __get_cpu_var(tasklet_vec).list; - __get_cpu_var(tasklet_vec).list = t; + t->next = NULL; + *__get_cpu_var(tasklet_vec).tail = t; + __get_cpu_var(tasklet_vec).tail = &(t->next); __raise_softirq_irqoff(TASKLET_SOFTIRQ); local_irq_enable(); } @@ -428,8 +433,9 @@ static void tasklet_hi_action(struct softirq_action *a) struct tasklet_struct *list; local_irq_disable(); - list = __get_cpu_var(tasklet_hi_vec).list; - __get_cpu_var(tasklet_hi_vec).list = NULL; + list = __get_cpu_var(tasklet_hi_vec).head; + __get_cpu_var(tasklet_hi_vec).head = NULL; + __get_cpu_var(tasklet_hi_vec).tail = &__get_cpu_var(tasklet_hi_vec).head; local_irq_enable(); while (list) { @@ -449,8 +455,9 @@ static void tasklet_hi_action(struct softirq_action *a) } local_irq_disable(); - t->next = __get_cpu_var(tasklet_hi_vec).list; - __get_cpu_var(tasklet_hi_vec).list = t; + t->next = NULL; + *__get_cpu_var(tasklet_hi_vec).tail = t; + __get_cpu_var(tasklet_hi_vec).tail = &(t->next); __raise_softirq_irqoff(HI_SOFTIRQ); local_irq_enable(); } @@ -487,6 +494,15 @@ EXPORT_SYMBOL(tasklet_kill); void __init softirq_init(void) { + int cpu; + + for_each_possible_cpu(cpu) { + per_cpu(tasklet_vec, cpu).tail = + &per_cpu(tasklet_vec, cpu).head; + per_cpu(tasklet_hi_vec, cpu).tail = + &per_cpu(tasklet_hi_vec, cpu).head; + } + open_softirq(TASKLET_SOFTIRQ, tasklet_action, NULL); open_softirq(HI_SOFTIRQ, tasklet_hi_action, NULL); } @@ -555,9 +571,12 @@ void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu) return; /* CPU is dead, so no lock needed. */ - for (i = &per_cpu(tasklet_vec, cpu).list; *i; i = &(*i)->next) { + for (i = &per_cpu(tasklet_vec, cpu).head; *i; i = &(*i)->next) { if (*i == t) { *i = t->next; + /* If this was the tail element, move the tail ptr */ + if (*i == NULL) + per_cpu(tasklet_vec, cpu).tail = i; return; } } @@ -566,20 +585,20 @@ void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu) static void takeover_tasklets(unsigned int cpu) { - struct tasklet_struct **i; - /* CPU is dead, so no lock needed. */ local_irq_disable(); /* Find end, append list for that CPU. */ - for (i = &__get_cpu_var(tasklet_vec).list; *i; i = &(*i)->next); - *i = per_cpu(tasklet_vec, cpu).list; - per_cpu(tasklet_vec, cpu).list = NULL; + *__get_cpu_var(tasklet_vec).tail = per_cpu(tasklet_vec, cpu).head; + __get_cpu_var(tasklet_vec).tail = per_cpu(tasklet_vec, cpu).tail; + per_cpu(tasklet_vec, cpu).head = NULL; + per_cpu(tasklet_vec, cpu).tail = &per_cpu(tasklet_vec, cpu).head; raise_softirq_irqoff(TASKLET_SOFTIRQ); - for (i = &__get_cpu_var(tasklet_hi_vec).list; *i; i = &(*i)->next); - *i = per_cpu(tasklet_hi_vec, cpu).list; - per_cpu(tasklet_hi_vec, cpu).list = NULL; + *__get_cpu_var(tasklet_hi_vec).tail = per_cpu(tasklet_hi_vec, cpu).head; + __get_cpu_var(tasklet_hi_vec).tail = per_cpu(tasklet_hi_vec, cpu).tail; + per_cpu(tasklet_hi_vec, cpu).head = NULL; + per_cpu(tasklet_hi_vec, cpu).tail = &per_cpu(tasklet_hi_vec, cpu).head; raise_softirq_irqoff(HI_SOFTIRQ); local_irq_enable(); |