From: <Viktor.Rosendahl@bmw.de>
To: <rostedt@goodmis.org>
Cc: <linux-trace-devel@vger.kernel.org>
Subject: Re: Adding latency tracking to trace-cmd
Date: Tue, 6 Apr 2021 20:24:19 +0000 [thread overview]
Message-ID: <65f872664c4e15b1f37d9877f6fe914612a7de1b.camel@bmw.de> (raw)
In-Reply-To: <c85bd8239b17619cac002c3d4d820ec0d46a2362.camel@bmw.de>
On Tue, 2021-04-06 at 22:03 +0200, Viktor Rosendahl wrote:
>
>
> The usefulness lies in the case where you have latencies that systematically
> occur very close to each other.
>
I should have dropped the "very" from the statement above.
>
>
> Admittedly, I have never detected any real world case like the one described
> above in the kernel but I don't think that it's completely unthinkable.
>
I forgot to mention that the kernel has a synthetic example of this situation in
the preemptirq_delay_test module, if you use the burst_size parameter.
If you want to see all the functions preemptirqtest_[0-9] in your stack traces,
then you probably need to use the --random option.
Then again this burst feature was implemented by me in order to test the
latency-collector.
best regards,
Viktor
next prev parent reply other threads:[~2021-04-06 20:31 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-24 16:54 Adding latency tracking to trace-cmd Steven Rostedt
2021-02-24 19:22 ` Viktor.Rosendahl
2021-02-24 20:10 ` Steven Rostedt
2021-04-06 17:38 ` Steven Rostedt
2021-04-06 20:03 ` Viktor.Rosendahl
2021-04-06 20:24 ` Viktor.Rosendahl [this message]
2021-04-06 20:42 ` Steven Rostedt
2021-04-08 21:01 ` Viktor Rosendahl
2021-04-08 21:17 ` Steven Rostedt
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