From: Viktor Rosendahl <viktor.rosendahl@gmail.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Joel Fernandes <joel@joelfernandes.org>,
Ingo Molnar <mingo@redhat.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 1/4] ftrace: Implement fs notification for preempt/irqsoff tracers
Date: Mon, 6 May 2019 01:54:04 +0200 [thread overview]
Message-ID: <b415ea04-e078-a73c-3609-56fb195841c3@gmail.com> (raw)
In-Reply-To: <20190505190133.49b5ea46@oasis.local.home>
On 5/6/19 1:01 AM, Steven Rostedt wrote:
> On Mon, 6 May 2019 00:39:15 +0200
> Viktor Rosendahl <viktor.rosendahl@gmail.com> wrote:
>
>> Can you explain more precisely what you agree with?
>>
>> The general idea of being able to trace bursts of latencies?
>
> One thing I have an issue with the current approach is the use of the
> trace file for this.
You mean that using fsnotify is kind of okayish but that it's confusing
for the
user because only a subset of tracers would send the fsnotify event when the
trace file is updated?
>
> Hmm, what about adding a notifier to tracing_max_latency instead? And
> do it not as a config option, but have it always enabled. It would send a
> notification when it changes, and that only happens when there's a new
> max latency. Would that work for you?
Yes, it seems to be OK since the tracing_max_latency is updated also
with the latest latency that exceeds the threshold when we are using
tracing_thresh. I will try to send a new version of the patch series
soon, with the modifications that have been discussed so far.
best regards,
Viktor
next prev parent reply other threads:[~2019-05-05 23:54 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-01 20:36 [PATCH v2 0/4] Some new features for the preempt/irqsoff tracers Viktor Rosendahl
2019-05-01 20:36 ` [PATCH v2 1/4] ftrace: Implement fs notification for " Viktor Rosendahl
2019-05-04 16:47 ` Joel Fernandes
2019-05-05 19:43 ` Steven Rostedt
2019-05-05 22:39 ` Viktor Rosendahl
2019-05-05 23:01 ` Steven Rostedt
2019-05-05 23:54 ` Viktor Rosendahl [this message]
2019-05-06 14:00 ` Joel Fernandes
2019-05-01 20:36 ` [PATCH v2 2/4] preemptirq_delay_test: Add the burst feature and a sysfs trigger Viktor Rosendahl
2019-05-01 20:36 ` [PATCH v2 3/4] Add the latency-collector to tools Viktor Rosendahl
2019-05-01 20:36 ` [PATCH v2 4/4] ftrace: Add an option for tracing console latencies Viktor Rosendahl
2019-05-02 1:38 ` Steven Rostedt
2019-05-02 18:37 ` Viktor Rosendahl
2019-05-02 21:12 ` Steven Rostedt
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