Re: [PATCH v4 3/3] tracing: add additional marks to signal very large delay
From: Byungchul Park
Date: Thu Nov 20 2014 - 01:33:36 EST
On Thu, Nov 20, 2014 at 03:11:19PM +0900, Namhyung Kim wrote:
> 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?
Yes it is okay. Steve asked for changing the value. :)
> >> + ' ' - less than or equal to 10 microsecond.
> >> The rest is the same as the 'trace' file.
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