From e77405ad80f53966524b5c31244e13fbbbecbd84 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2009 14:17:06 -0400 Subject: tracing: pass around ring buffer instead of tracer The latency tracers (irqsoff and wakeup) can swap trace buffers on the fly. If an event is happening and has reserved data on one of the buffers, and the latency tracer swaps the global buffer with the max buffer, the result is that the event may commit the data to the wrong buffer. This patch changes the API to the trace recording to be recieve the buffer that was used to reserve a commit. Then this buffer can be passed in to the commit. Signed-off-by: Steven Rostedt --- kernel/trace/trace_power.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) (limited to 'kernel/trace/trace_power.c') diff --git a/kernel/trace/trace_power.c b/kernel/trace/trace_power.c index a5d5a4f7745..fe1a00f1445 100644 --- a/kernel/trace/trace_power.c +++ b/kernel/trace/trace_power.c @@ -38,6 +38,7 @@ static void probe_power_end(struct power_trace *it) { struct ftrace_event_call *call = &event_power; struct ring_buffer_event *event; + struct ring_buffer *buffer; struct trace_power *entry; struct trace_array_cpu *data; struct trace_array *tr = power_trace; @@ -45,18 +46,20 @@ static void probe_power_end(struct power_trace *it) if (!trace_power_enabled) return; + buffer = tr->buffer; + preempt_disable(); it->end = ktime_get(); data = tr->data[smp_processor_id()]; - event = trace_buffer_lock_reserve(tr, TRACE_POWER, + event = trace_buffer_lock_reserve(buffer, TRACE_POWER, sizeof(*entry), 0, 0); if (!event) goto out; entry = ring_buffer_event_data(event); entry->state_data = *it; - if (!filter_check_discard(call, entry, tr->buffer, event)) - trace_buffer_unlock_commit(tr, event, 0, 0); + if (!filter_check_discard(call, entry, buffer, event)) + trace_buffer_unlock_commit(buffer, event, 0, 0); out: preempt_enable(); } @@ -66,6 +69,7 @@ static void probe_power_mark(struct power_trace *it, unsigned int type, { struct ftrace_event_call *call = &event_power; struct ring_buffer_event *event; + struct ring_buffer *buffer; struct trace_power *entry; struct trace_array_cpu *data; struct trace_array *tr = power_trace; @@ -73,6 +77,8 @@ static void probe_power_mark(struct power_trace *it, unsigned int type, if (!trace_power_enabled) return; + buffer = tr->buffer; + memset(it, 0, sizeof(struct power_trace)); it->state = level; it->type = type; @@ -81,14 +87,14 @@ static void probe_power_mark(struct power_trace *it, unsigned int type, it->end = it->stamp; data = tr->data[smp_processor_id()]; - event = trace_buffer_lock_reserve(tr, TRACE_POWER, + event = trace_buffer_lock_reserve(buffer, TRACE_POWER, sizeof(*entry), 0, 0); if (!event) goto out; entry = ring_buffer_event_data(event); entry->state_data = *it; - if (!filter_check_discard(call, entry, tr->buffer, event)) - trace_buffer_unlock_commit(tr, event, 0, 0); + if (!filter_check_discard(call, entry, buffer, event)) + trace_buffer_unlock_commit(buffer, event, 0, 0); out: preempt_enable(); } -- cgit v1.2.3