From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Cc: Steven Rostedt <rostedt@goodmis.org>,
Ingo Molnar <mingo@redhat.com>, Shuah Khan <shuah@kernel.org>,
linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-rt-users@vger.kernel.org, joseph.salisbury@canonical.com,
Shuah Khan <skhan@linuxfoundation.org>
Subject: Re: [PATCH v2] selftests/ftrace: Do not trace do_softirq because of PREEMPT_RT
Date: Thu, 10 Feb 2022 15:10:44 +0100 [thread overview]
Message-ID: <YgUc5HxfIdJ0Z5AN@linutronix.de> (raw)
In-Reply-To: <546f147d-1682-fb92-42e5-7247dc19dcf1@canonical.com>
On 2022-02-10 15:05:24 [+0100], Krzysztof Kozlowski wrote:
> On 10/02/2022 14:47, Sebastian Andrzej Siewior wrote:
> > On 2022-02-10 09:33:56 [+0100], Krzysztof Kozlowski wrote:
> >> The PREEMPT_RT patchset does not use soft IRQs thus trying to filter for
> >> do_softirq fails for such kernel:
> >
> > PREEMPT_RT does use soft IRQs.
>
> Correct. It does not use do_softirq() code, but follows different path
> with ksoftirqd.
> Shall I rephrase it towards something like this? Or maybe you have some
> more accurate description?
It would be good to describe what the purpose of the change in terms of
the actual problem and the aimed solution.
> The implementation detail is that do_softirq() is in ifndef.
So let me ask again. We have
FUNC1="schedule"
FUNC2="do_softirq"
What is the purpose of this? Do you need FUNC2 when ksoftirqd is run or
when softirqs are served? Not sure how scheduler_tick fits in all this.
> Best regards,
> Krzysztof
Sebastian
next prev parent reply other threads:[~2022-02-10 14:10 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-10 8:33 [PATCH v2] selftests/ftrace: Do not trace do_softirq because of PREEMPT_RT Krzysztof Kozlowski
2022-02-10 13:47 ` Sebastian Andrzej Siewior
2022-02-10 14:05 ` Krzysztof Kozlowski
2022-02-10 14:10 ` Sebastian Andrzej Siewior [this message]
2022-02-10 14:13 ` Krzysztof Kozlowski
2022-02-10 14:48 ` Sebastian Andrzej Siewior
2022-02-10 15:07 ` Steven Rostedt
2022-02-10 15:05 ` Steven Rostedt
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YgUc5HxfIdJ0Z5AN@linutronix.de \
--to=bigeasy@linutronix.de \
--cc=joseph.salisbury@canonical.com \
--cc=krzysztof.kozlowski@canonical.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=linux-rt-users@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=rostedt@goodmis.org \
--cc=shuah@kernel.org \
--cc=skhan@linuxfoundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox