[dpdk-dev] [RFC v2 2/2] test/rcu_qsbr: add API and functional tests

[Honnappa Nagarahalli]

> 
> On Sat, Dec 22, 2018 at 11:30:51PM -0800, Stephen Hemminger wrote:
> > On Fri, 21 Dec 2018 20:14:20 -0600
> > Honnappa Nagarahalli <honnappa.nagarahalli at arm.com> wrote:
> >
> > > From: Dharmik Thakkar <dharmik.thakkar at arm.com>
> > >
> > > Add API positive/negative test cases and functional tests.
> > >
> > > Signed-off-by: Malvika Gupta <malvika.gupta at arm.com>
> > > Signed-off-by: Dharmik Thakkar <dharmik.thakkar at arm.com>
> > > Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli at arm.com>
> > > Reviewed-by: Gavin Hu <gavin.hu at arm.com>
> >
> > Just a thought, could you build stress tests like the kernel RCU tests?
> > One worry is that RCU does not play well with blocking threads (and
> sometimes preemption).
Handling blocking threads is supported right now through register_thread/unregister_thread APIs. If a thread has to make a call to a blocking API, it is expected to unregister itself first. It will be improved further in V3.
However, I am not sure what needs to be done for preemption. I would imagine that the threads will be scheduled back at some point (depending on the scheduling policy). If they were using the data structure the updater has to wait.

> 
> There are similar tests in the userspace RCU library, as well, which can be
> found at http://liburcu.
I looked at these tests. There is perftest/rperftest(reader only)/uperftest(updater only)/stresstest/benchmark. Currently, we have covered perftest/stresstest/benchmark pretty well (perf numbers need to be added). We will add rperftest and uperftest.

> 
> 							Thanx, Paul