ring_buffer_alloc_read_page
ring_buffer_alloc_read_page(struct trace_buffer *buffer, int cpu);
EXPORT_SYMBOL_GPL(ring_buffer_alloc_read_page);
bpage = ring_buffer_alloc_read_page(buffer, cpu);
info->spare = ring_buffer_alloc_read_page(iter->array_buffer->buffer,
ref->page = ring_buffer_alloc_read_page(ref->buffer, iter->cpu_file);