Re: Question about sched_setaffinity()

[Paul E. McKenney]

On Wed, May 01, 2019 at 03:16:55PM -0400, Steven Rostedt wrote:
> On Wed, 1 May 2019 12:12:13 -0700
> "Paul E. McKenney" <paulmck@xxxxxxxxxxxxx> wrote:
> 
> 
> > OK, what I did was to apply the patch at the end of this email to -rcu
> > branch dev, then run rcutorture as follows:
> > 
> > nohup tools/testing/selftests/rcutorture/bin/kvm.sh --cpus 8 --duration 2 --configs "TRIVIAL" --bootargs "trace_event=sched:sched_switch,sched:sched_wakeup ftrace=function_graph ftrace_graph_filter=sched_setaffinity,migration_cpu_stop"
> > 
> > This resulted in the console output that I placed here:
> > 
> > http://www2.rdrop.com/~paulmck/submission/console.log.gz
> > 
> > But I don't see calls to sched_setaffinity() or migration_cpu_stop().
> > Steve, is something else needed on the kernel command line in addition to
> > the following?
> > 
> > ftrace=function_graph ftrace_graph_filter=sched_setaffinity,migration_cpu_stop
> 
> Do you have function graph enabled in the config?
> 
> [    2.098303] ftrace bootup tracer 'function_graph' not registered.

I guess I don't!  Thank you, will fix.

Let's see...

My .config has CONFIG_HAVE_FUNCTION_GRAPH_TRACER=y.  It looks like I
need CONFIG_FUNCTION_GRAPH_TRACER=y, which I don't have.  And it looks
like that needs CONFIG_FUNCTION_TRACER=y, which I also don't have.
But I do have CONFIG_HAVE_FUNCTION_TRACER=y.  So I should add this
to my rcutorture command line:

--kconfig "CONFIG_FUNCTION_TRACER=y CONFIG_FUNCTION_GRAPH_TRACER=y".

I fired this up.  Here is hoping!  ;-)

And it does have sched_setaffinity(), woo-hoo!!!  I overwrote the old file:

	http://www2.rdrop.com/~paulmck/submission/console.log.gz

							Thanx, Paul