linux-kernel - Re: [PATCH v2 22/32] selftests/ftrace: Add ringbuffer size changing testcase

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 30 Aug 2018 16:12:18 +0900
From:   Masami Hiramatsu <mhiramat@...nel.org>
To:     Steven Rostedt <rostedt@...dmis.org>
Cc:     Shuah Khan <shuah@...nel.org>, Ingo Molnar <mingo@...hat.com>,
        linux-kselftest@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 22/32] selftests/ftrace: Add ringbuffer size changing
 testcase

On Fri, 24 Aug 2018 19:18:36 -0400
Steven Rostedt <rostedt@...dmis.org> wrote:

> On Fri, 17 Aug 2018 01:39:34 +0900
> Masami Hiramatsu <mhiramat@...nel.org> wrote:
> 
> > Add a testcase for changing ringbuffer size. This tests
> > not only ringbuffer size but also tests the imbalance
> > per-cpu buffer size change too.
> > 
> > Signed-off-by: Masami Hiramatsu <mhiramat@...nel.org>
> 
> I'm fine with this, but one day I need to port over some of my other
> tests. I have a test that stresses the ring buffer size (basically
> checks to see if it can cause an oom). I need to port that to
> selftests. But for now...

Hmm, such stress test is not good for kselftest, since it can cause
oom and kill some test process. Maybe we should have such stresstest
framework (which allows test to crash kernel)

> 
> Acked-by: Steven Rostedt (VMware) <rostedt@...dmis.org>
> 
> But, one more thing..
> 
> > ---
> >  .../ftrace/test.d/00basic/ringbuffer_size.tc       |   21 ++++++++++++++++++++
> >  1 file changed, 21 insertions(+)
> >  create mode 100644 tools/testing/selftests/ftrace/test.d/00basic/ringbuffer_size.tc
> > 
> > diff --git a/tools/testing/selftests/ftrace/test.d/00basic/ringbuffer_size.tc b/tools/testing/selftests/ftrace/test.d/00basic/ringbuffer_size.tc
> > new file mode 100644
> > index 000000000000..9224f33b3194
> > --- /dev/null
> > +++ b/tools/testing/selftests/ftrace/test.d/00basic/ringbuffer_size.tc
> > @@ -0,0 +1,21 @@
> > +#!/bin/sh
> > +# SPDX-License-Identifier: GPL-2.0
> > +# description: Change the ringbuffer size
> 
> Should add:
> 
>  # flags: instance

OK, I'll add it.

Thank you!

> 
> As this works for instances as well.
> 
> -- Steve
> 
> > +
> > +rb_size_test() {
> > +ORIG=`cat buffer_size_kb`
> > +
> > +expr $ORIG / 2 > buffer_size_kb
> > +
> > +expr $ORIG \* 2 > buffer_size_kb
> > +
> > +echo $ORIG > buffer_size_kb
> > +}
> > +
> > +rb_size_test
> > +
> > +: "If per-cpu buffer is supported, imbalance it"
> > +if [ -d per_cpu/cpu0 ]; then
> > +  cd per_cpu/cpu0
> > +  rb_size_test
> > +fi
> 


-- 
Masami Hiramatsu <mhiramat@...nel.org>