buf->read_timer_enabled = 0;
}
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
-
enum cpuhp_state lttng_rb_hp_prepare;
enum cpuhp_state lttng_rb_hp_online;
}
EXPORT_SYMBOL_GPL(lttng_cpuhp_rb_frontend_offline);
-#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
-
-#ifdef CONFIG_HOTPLUG_CPU
-
-/**
- * lib_ring_buffer_cpu_hp_callback - CPU hotplug callback
- * @nb: notifier block
- * @action: hotplug action to take
- * @hcpu: CPU number
- *
- * Returns the success/failure of the operation. (%NOTIFY_OK, %NOTIFY_BAD)
- */
-static
-int lib_ring_buffer_cpu_hp_callback(struct notifier_block *nb,
- unsigned long action,
- void *hcpu)
-{
- unsigned int cpu = (unsigned long)hcpu;
- struct channel *chan = container_of(nb, struct channel,
- cpu_hp_notifier);
- struct lib_ring_buffer *buf = per_cpu_ptr(chan->backend.buf, cpu);
- const struct lib_ring_buffer_config *config = &chan->backend.config;
-
- if (!chan->cpu_hp_enable)
- return NOTIFY_DONE;
-
- CHAN_WARN_ON(chan, config->alloc == RING_BUFFER_ALLOC_GLOBAL);
-
- switch (action) {
- case CPU_DOWN_FAILED:
- case CPU_DOWN_FAILED_FROZEN:
- case CPU_ONLINE:
- case CPU_ONLINE_FROZEN:
- wake_up_interruptible(&chan->hp_wait);
- lib_ring_buffer_start_switch_timer(buf);
- lib_ring_buffer_start_read_timer(buf);
- return NOTIFY_OK;
-
- case CPU_DOWN_PREPARE:
- case CPU_DOWN_PREPARE_FROZEN:
- lib_ring_buffer_stop_switch_timer(buf);
- lib_ring_buffer_stop_read_timer(buf);
- return NOTIFY_OK;
-
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
- /*
- * Performing a buffer switch on a remote CPU. Performed by
- * the CPU responsible for doing the hotunplug after the target
- * CPU stopped running completely. Ensures that all data
- * from that remote CPU is flushed.
- */
- lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
- return NOTIFY_OK;
-
- default:
- return NOTIFY_DONE;
- }
-}
-
-#endif
-
-#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
-
#if defined(CONFIG_NO_HZ) && defined(CONFIG_LIB_RING_BUFFER)
/*
* For per-cpu buffers, call the reader wakeups before switching the buffer, so
* concurrency.
*/
#endif /* CONFIG_NO_HZ */
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
{
int ret;
&chan->cpuhp_prepare.node);
WARN_ON(ret);
}
-#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
- {
- int cpu;
-
-#ifdef CONFIG_HOTPLUG_CPU
- get_online_cpus();
- chan->cpu_hp_enable = 0;
- for_each_online_cpu(cpu) {
- struct lib_ring_buffer *buf = per_cpu_ptr(chan->backend.buf,
- cpu);
- lib_ring_buffer_stop_switch_timer(buf);
- lib_ring_buffer_stop_read_timer(buf);
- }
- put_online_cpus();
- unregister_cpu_notifier(&chan->cpu_hp_notifier);
-#else
- for_each_possible_cpu(cpu) {
- struct lib_ring_buffer *buf = per_cpu_ptr(chan->backend.buf,
- cpu);
- lib_ring_buffer_stop_switch_timer(buf);
- lib_ring_buffer_stop_read_timer(buf);
- }
-#endif
- }
-#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
} else {
struct lib_ring_buffer *buf = chan->backend.buf;
init_waitqueue_head(&chan->hp_wait);
if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
chan->cpuhp_prepare.component = LTTNG_RING_BUFFER_FRONTEND;
ret = cpuhp_state_add_instance_nocalls(lttng_rb_hp_prepare,
&chan->cpuhp_prepare.node);
&chan->cpuhp_online.node);
if (ret)
goto cpuhp_online_error;
-#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
- {
- int cpu;
- /*
- * In case of non-hotplug cpu, if the ring-buffer is allocated
- * in early initcall, it will not be notified of secondary cpus.
- * In that off case, we need to allocate for all possible cpus.
- */
-#ifdef CONFIG_HOTPLUG_CPU
- chan->cpu_hp_notifier.notifier_call =
- lib_ring_buffer_cpu_hp_callback;
- chan->cpu_hp_notifier.priority = 6;
- register_cpu_notifier(&chan->cpu_hp_notifier);
-
- get_online_cpus();
- for_each_online_cpu(cpu) {
- struct lib_ring_buffer *buf = per_cpu_ptr(chan->backend.buf,
- cpu);
- spin_lock(&per_cpu(ring_buffer_nohz_lock, cpu));
- lib_ring_buffer_start_switch_timer(buf);
- lib_ring_buffer_start_read_timer(buf);
- spin_unlock(&per_cpu(ring_buffer_nohz_lock, cpu));
- }
- chan->cpu_hp_enable = 1;
- put_online_cpus();
-#else
- for_each_possible_cpu(cpu) {
- struct lib_ring_buffer *buf = per_cpu_ptr(chan->backend.buf,
- cpu);
- spin_lock(&per_cpu(ring_buffer_nohz_lock, cpu));
- lib_ring_buffer_start_switch_timer(buf);
- lib_ring_buffer_start_read_timer(buf);
- spin_unlock(&per_cpu(ring_buffer_nohz_lock, cpu));
- }
-#endif
- }
-#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
#if defined(CONFIG_NO_HZ) && defined(CONFIG_LIB_RING_BUFFER)
/* Only benefit from NO_HZ idle with per-cpu buffers for now. */
return chan;
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
cpuhp_online_error:
ret = cpuhp_state_remove_instance_nocalls(lttng_rb_hp_prepare,
&chan->cpuhp_prepare.node);
WARN_ON(ret);
cpuhp_prepare_error:
-#endif /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
error_free_backend:
channel_backend_free(&chan->backend);
error: