From: Robert Richter Date: Fri, 31 Jul 2009 12:58:04 +0000 (+0200) Subject: ring-buffer: consolidate interface of rb_buffer_peek() X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=d8eeb2d3b26d25c44c10f28430e2157a2d20bd1d;p=linux-beck.git ring-buffer: consolidate interface of rb_buffer_peek() rb_buffer_peek() operates with struct ring_buffer_per_cpu *cpu_buffer only. Thus, instead of passing variables buffer and cpu it is better to use cpu_buffer directly. This also reduces the risk of races since cpu_buffer is not calculated twice. Signed-off-by: Robert Richter LKML-Reference: <1249045084-3028-1-git-send-email-robert.richter@amd.com> Signed-off-by: Steven Rostedt --- diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 454e74e718cf..8786c350b4ca 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2997,15 +2997,12 @@ static void rb_advance_iter(struct ring_buffer_iter *iter) } static struct ring_buffer_event * -rb_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts) +rb_buffer_peek(struct ring_buffer_per_cpu *cpu_buffer, u64 *ts) { - struct ring_buffer_per_cpu *cpu_buffer; struct ring_buffer_event *event; struct buffer_page *reader; int nr_loops = 0; - cpu_buffer = buffer->buffers[cpu]; - again: /* * We repeat when a timestamp is encountered. It is possible @@ -3049,7 +3046,7 @@ rb_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts) case RINGBUF_TYPE_DATA: if (ts) { *ts = cpu_buffer->read_stamp + event->time_delta; - ring_buffer_normalize_time_stamp(buffer, + ring_buffer_normalize_time_stamp(cpu_buffer->buffer, cpu_buffer->cpu, ts); } return event; @@ -3168,7 +3165,7 @@ ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts) local_irq_save(flags); if (dolock) spin_lock(&cpu_buffer->reader_lock); - event = rb_buffer_peek(buffer, cpu, ts); + event = rb_buffer_peek(cpu_buffer, ts); if (event && event->type_len == RINGBUF_TYPE_PADDING) rb_advance_reader(cpu_buffer); if (dolock) @@ -3237,7 +3234,7 @@ ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts) if (dolock) spin_lock(&cpu_buffer->reader_lock); - event = rb_buffer_peek(buffer, cpu, ts); + event = rb_buffer_peek(cpu_buffer, ts); if (event) rb_advance_reader(cpu_buffer);