diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/ring_buffer.c | 40 |
1 files changed, 35 insertions, 5 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 9607918..5040d44 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -445,7 +445,10 @@ int ring_buffer_print_page_header(struct trace_seq *s) struct rb_irq_work { struct irq_work work; wait_queue_head_t waiters; + wait_queue_head_t full_waiters; bool waiters_pending; + bool full_waiters_pending; + bool wakeup_full; }; /* @@ -527,6 +530,10 @@ static void rb_wake_up_waiters(struct irq_work *work) struct rb_irq_work *rbwork = container_of(work, struct rb_irq_work, work); wake_up_all(&rbwork->waiters); + if (rbwork->wakeup_full) { + rbwork->wakeup_full = false; + wake_up_all(&rbwork->full_waiters); + } } /** @@ -551,9 +558,11 @@ int ring_buffer_wait(struct ring_buffer *buffer, int cpu, bool full) * data in any cpu buffer, or a specific buffer, put the * caller on the appropriate wait queue. */ - if (cpu == RING_BUFFER_ALL_CPUS) + if (cpu == RING_BUFFER_ALL_CPUS) { work = &buffer->irq_work; - else { + /* Full only makes sense on per cpu reads */ + full = false; + } else { if (!cpumask_test_cpu(cpu, buffer->cpumask)) return -ENODEV; cpu_buffer = buffer->buffers[cpu]; @@ -562,7 +571,10 @@ int ring_buffer_wait(struct ring_buffer *buffer, int cpu, bool full) while (true) { - prepare_to_wait(&work->waiters, &wait, TASK_INTERRUPTIBLE); + if (full) + prepare_to_wait(&work->full_waiters, &wait, TASK_INTERRUPTIBLE); + else + prepare_to_wait(&work->waiters, &wait, TASK_INTERRUPTIBLE); /* * The events can happen in critical sections where @@ -584,7 +596,10 @@ int ring_buffer_wait(struct ring_buffer *buffer, int cpu, bool full) * that is necessary is that the wake up happens after * a task has been queued. It's OK for spurious wake ups. */ - work->waiters_pending = true; + if (full) + work->full_waiters_pending = true; + else + work->waiters_pending = true; if (signal_pending(current)) { ret = -EINTR; @@ -613,7 +628,10 @@ int ring_buffer_wait(struct ring_buffer *buffer, int cpu, bool full) schedule(); } - finish_wait(&work->waiters, &wait); + if (full) + finish_wait(&work->full_waiters, &wait); + else + finish_wait(&work->waiters, &wait); return ret; } @@ -1228,6 +1246,7 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int nr_pages, int cpu) init_completion(&cpu_buffer->update_done); init_irq_work(&cpu_buffer->irq_work.work, rb_wake_up_waiters); init_waitqueue_head(&cpu_buffer->irq_work.waiters); + init_waitqueue_head(&cpu_buffer->irq_work.full_waiters); bpage = kzalloc_node(ALIGN(sizeof(*bpage), cache_line_size()), GFP_KERNEL, cpu_to_node(cpu)); @@ -2799,6 +2818,8 @@ static void rb_commit(struct ring_buffer_per_cpu *cpu_buffer, static __always_inline void rb_wakeups(struct ring_buffer *buffer, struct ring_buffer_per_cpu *cpu_buffer) { + bool pagebusy; + if (buffer->irq_work.waiters_pending) { buffer->irq_work.waiters_pending = false; /* irq_work_queue() supplies it's own memory barriers */ @@ -2810,6 +2831,15 @@ rb_wakeups(struct ring_buffer *buffer, struct ring_buffer_per_cpu *cpu_buffer) /* irq_work_queue() supplies it's own memory barriers */ irq_work_queue(&cpu_buffer->irq_work.work); } + + pagebusy = cpu_buffer->reader_page == cpu_buffer->commit_page; + + if (!pagebusy && cpu_buffer->irq_work.full_waiters_pending) { + cpu_buffer->irq_work.wakeup_full = true; + cpu_buffer->irq_work.full_waiters_pending = false; + /* irq_work_queue() supplies it's own memory barriers */ + irq_work_queue(&cpu_buffer->irq_work.work); + } } /** |
