Re: [PATCH v4 3/3] tracing: add additional marks to signal very large delay

From: Namhyung Kim
Date: Thu Nov 20 2014 - 01:11:27 EST


On Wed, 19 Nov 2014 13:35:15 -0500, Steven Rostedt wrote:
> On Tue, 18 Nov 2014 14:57:26 +0900
> byungchul.park@xxxxxxx wrote:
>
>> From: Byungchul Park <byungchul.park@xxxxxxx>
>>
>> Currently, some tracers tracing latency print "!" or "+" just after time
>> to signal overhead, depending on the interval between events. Even it is
>> usually enough to do that, we sometimes need to be signaled for bigger
>> interval than 100 micro seconds.
>>
>> Signed-off-by: Byungchul Park <byungchul.park@xxxxxxx>
>> ---
>> Documentation/trace/ftrace.txt | 8 +++++---
>> kernel/trace/trace_output.c | 23 ++++++++++++++++++-----
>> 2 files changed, 23 insertions(+), 8 deletions(-)
>>
>> diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt
>> index f827e2f..64efb3e 100644
>> --- a/Documentation/trace/ftrace.txt
>> +++ b/Documentation/trace/ftrace.txt
>> @@ -680,9 +680,11 @@ The above is mostly meaningful for kernel developers.
>> needs to be fixed to be only relative to the same CPU.
>> The marks are determined by the difference between this
>> current trace and the next trace.
>> - '!' - greater than preempt_mark_thresh (default 100)
>> - '+' - greater than 1 microsecond
>> - ' ' - less than or equal to 1 microsecond.
>> + '$' - greater than 1 second
>> + '#' - greater than 1000 microsecond
>> + '!' - greater than 100 microsecond
>> + '+' - greater than 10 microsecond

I've noticed that it's now changed from 1 msec to 10 msec. Is it okay?

Thanks,
Namhyung


>> + ' ' - less than or equal to 10 microsecond.
>>
>> The rest is the same as the 'trace' file.
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