#include <linux/seq_file.h>
#include <linux/notifier.h>
#include <linux/irqflags.h>
-#include <linux/irq_work.h>
#include <linux/debugfs.h>
#include <linux/pagemap.h>
#include <linux/hardirq.h>
*/
static DEFINE_PER_CPU(bool, trace_cmdline_save);
-/*
- * When a reader is waiting for data, then this variable is
- * set to true.
- */
-static bool trace_wakeup_needed;
-
-static struct irq_work trace_work_wakeup;
-
/*
* Kill all tracing for good (never come back).
* It is initialized to 1 but will turn to zero if the initialization
#endif
-/* trace_wait is a waitqueue for tasks blocked on trace_poll */
-static DECLARE_WAIT_QUEUE_HEAD(trace_wait);
-
/* trace_flags holds trace_options default values */
unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK |
TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | TRACE_ITER_SLEEP_TIME |
TRACE_ITER_GRAPH_TIME | TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE |
TRACE_ITER_IRQ_INFO | TRACE_ITER_MARKERS;
-/**
- * trace_wake_up - wake up tasks waiting for trace input
- *
- * Schedules a delayed work to wake up any task that is blocked on the
- * trace_wait queue. These is used with trace_poll for tasks polling the
- * trace.
- */
-static void trace_wake_up(struct irq_work *work)
-{
- wake_up_all(&trace_wait);
-
-}
-
/**
* tracing_on - enable tracing buffers
*
static void default_wait_pipe(struct trace_iterator *iter)
{
- DEFINE_WAIT(wait);
-
- prepare_to_wait(&trace_wait, &wait, TASK_INTERRUPTIBLE);
-
- /*
- * The events can happen in critical sections where
- * checking a work queue can cause deadlocks.
- * After adding a task to the queue, this flag is set
- * only to notify events to try to wake up the queue
- * using irq_work.
- *
- * We don't clear it even if the buffer is no longer
- * empty. The flag only causes the next event to run
- * irq_work to do the work queue wake up. The worse
- * that can happen if we race with !trace_empty() is that
- * an event will cause an irq_work to try to wake up
- * an empty queue.
- *
- * There's no reason to protect this flag either, as
- * the work queue and irq_work logic will do the necessary
- * synchronization for the wake ups. The only thing
- * that is necessary is that the wake up happens after
- * a task has been queued. It's OK for spurious wake ups.
- */
- trace_wakeup_needed = true;
-
- if (trace_empty(iter))
- schedule();
+ /* Iterators are static, they should be filled or empty */
+ if (trace_buffer_iter(iter, iter->cpu_file))
+ return;
- finish_wait(&trace_wait, &wait);
+ ring_buffer_wait(iter->tr->buffer, iter->cpu_file);
}
/**
__buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *event)
{
__this_cpu_write(trace_cmdline_save, true);
- if (trace_wakeup_needed) {
- trace_wakeup_needed = false;
- /* irq_work_queue() supplies it's own memory barriers */
- irq_work_queue(&trace_work_wakeup);
- }
ring_buffer_unlock_commit(buffer, event);
}
static unsigned int
trace_poll(struct trace_iterator *iter, struct file *filp, poll_table *poll_table)
{
- if (trace_flags & TRACE_ITER_BLOCK) {
+ /* Iterators are static, they should be filled or empty */
+ if (trace_buffer_iter(iter, iter->cpu_file))
+ return POLLIN | POLLRDNORM;
+
+ if (trace_flags & TRACE_ITER_BLOCK)
/*
* Always select as readable when in blocking mode
*/
return POLLIN | POLLRDNORM;
- } else {
- if (!trace_empty(iter))
- return POLLIN | POLLRDNORM;
- trace_wakeup_needed = true;
- poll_wait(filp, &trace_wait, poll_table);
- if (!trace_empty(iter))
- return POLLIN | POLLRDNORM;
-
- return 0;
- }
+ else
+ return ring_buffer_poll_wait(iter->tr->buffer, iter->cpu_file,
+ filp, poll_table);
}
static unsigned int
#endif
trace_init_cmdlines();
- init_irq_work(&trace_work_wakeup, trace_wake_up);
register_tracer(&nop_trace);