From e5fd91f1ef340da553f7a79da9540c3db711c937 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Tue, 8 Sep 2015 01:01:14 -0300 Subject: Linux-libre 4.2-gnu --- kernel/events/ring_buffer.c | 39 ++++++++++++++++++++++++++++++++------- 1 file changed, 32 insertions(+), 7 deletions(-) (limited to 'kernel/events/ring_buffer.c') diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c index 725c41608..c8aa3f75b 100644 --- a/kernel/events/ring_buffer.c +++ b/kernel/events/ring_buffer.c @@ -141,7 +141,7 @@ int perf_output_begin(struct perf_output_handle *handle, perf_output_get_handle(handle); do { - tail = ACCESS_ONCE(rb->user_page->data_tail); + tail = READ_ONCE_CTRL(rb->user_page->data_tail); offset = head = local_read(&rb->head); if (!rb->overwrite && unlikely(CIRC_SPACE(head, tail, perf_data_size(rb)) < size)) @@ -221,6 +221,8 @@ void perf_output_end(struct perf_output_handle *handle) rcu_read_unlock(); } +static void rb_irq_work(struct irq_work *work); + static void ring_buffer_init(struct ring_buffer *rb, long watermark, int flags) { @@ -241,6 +243,16 @@ ring_buffer_init(struct ring_buffer *rb, long watermark, int flags) INIT_LIST_HEAD(&rb->event_list); spin_lock_init(&rb->event_lock); + init_irq_work(&rb->irq_work, rb_irq_work); +} + +static void ring_buffer_put_async(struct ring_buffer *rb) +{ + if (!atomic_dec_and_test(&rb->refcount)) + return; + + rb->rcu_head.next = (void *)rb; + irq_work_queue(&rb->irq_work); } /* @@ -319,7 +331,7 @@ err_put: rb_free_aux(rb); err: - ring_buffer_put(rb); + ring_buffer_put_async(rb); handle->event = NULL; return NULL; @@ -370,7 +382,7 @@ void perf_aux_output_end(struct perf_output_handle *handle, unsigned long size, local_set(&rb->aux_nest, 0); rb_free_aux(rb); - ring_buffer_put(rb); + ring_buffer_put_async(rb); } /* @@ -547,17 +559,30 @@ static void __rb_free_aux(struct ring_buffer *rb) rb->aux_priv = NULL; } - for (pg = 0; pg < rb->aux_nr_pages; pg++) - rb_free_aux_page(rb, pg); + if (rb->aux_nr_pages) { + for (pg = 0; pg < rb->aux_nr_pages; pg++) + rb_free_aux_page(rb, pg); - kfree(rb->aux_pages); - rb->aux_nr_pages = 0; + kfree(rb->aux_pages); + rb->aux_nr_pages = 0; + } } void rb_free_aux(struct ring_buffer *rb) { if (atomic_dec_and_test(&rb->aux_refcount)) + irq_work_queue(&rb->irq_work); +} + +static void rb_irq_work(struct irq_work *work) +{ + struct ring_buffer *rb = container_of(work, struct ring_buffer, irq_work); + + if (!atomic_read(&rb->aux_refcount)) __rb_free_aux(rb); + + if (rb->rcu_head.next == (void *)rb) + call_rcu(&rb->rcu_head, rb_free_rcu); } #ifndef CONFIG_PERF_USE_VMALLOC -- cgit v1.2.3-54-g00ecf