Re: [PATCH V2 -tip 3/4] Tracing/ftrace: Adapt mmiotrace to the newtype of print_line

From: Frederic Weisbecker
Date: Tue Sep 30 2008 - 12:14:02 EST


Ingo Molnar wrote:
> * Frédéric Weisbecker <fweisbec@xxxxxxxxx> wrote:
>
>> 2008/9/30 Steven Rostedt <rostedt@xxxxxxxxxxx>:
>>> OK, I'll nuke the ring_buffer_lock :-/
>>>
>>> The trace_pipe calls that and then calls print_trace_line which will
>>> eventually lock the buffer again. This is a bug on my part. I'll fix that
>>> today.
>>>
>>> Thanks,
>> Strange, I can't see any case where print_trace_line could call the
>> ring_buffer_lock.
>> Hmm, I will see in your patch.
>>
>> Ingo, I just saw one damage from the merging, trace_empty() returns
>> TRACE_TYPE_HANDLED. The type is wrong, it should return 1. It's not
>> urgent since the value is the same. Should I send a patch for such a
>> small error?
>
> yes, please do. One too many patch is far better than one too few ;-)
>
> Ingo
>

:)

Here it is!

Subject: [PATCH -tip] Tracing/ftrace: correct return value of trace_empty

Correct the value's type of trace_empty function

Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
---
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 6a1c76b..da3789d 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1686,7 +1686,7 @@ static int trace_empty(struct trace_iterator *iter)
if (!ring_buffer_iter_empty(iter->buffer_iter[cpu]))
return 0;
}
- return TRACE_TYPE_HANDLED;
+ return 1;
}

static enum print_line_t print_trace_line(struct trace_iterator *iter)


diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 6a1c76b..da3789d 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1686,7 +1686,7 @@ static int trace_empty(struct trace_iterator *iter)
if (!ring_buffer_iter_empty(iter->buffer_iter[cpu]))
return 0;
}
- return TRACE_TYPE_HANDLED;
+ return 1;
}

static enum print_line_t print_trace_line(struct trace_iterator *iter)
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/