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

[Steven Rostedt]

On Fri, 31 Aug 2018 08:35:28 +0900
Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote:

> On Thu, 30 Aug 2018 11:50:55 -0400
> Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> 
> > On Thu, 30 Aug 2018 16:12:18 +0900
> > Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote:
> >   
> > > > 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)  
> > 
> > The point of the test is to make sure that it doesn't kill
> > everything :-)  The ring buffer code is suppose to detect that it will
> > cause an OOM, and if it does that's considered a failure.  
> 
> Ah, OK, so the test itself must not cause OOM. That's reasonable. :)
> 
> > 
> > Just like any other test, if it fails, it can crash the kernel. But the
> > ring buffer code is suppose to be able to keep the kernel from crashing
> > (including triggering OOM) if the buffer size is stressed.
> > 
> > Maybe I'll port that over today :-/  
> 
> Looking forward it!
> 

Unfortunately, I didn't get to it, and will be on PTO for the next 4
days. Perhaps next week.

-- Steve