Re: [v2,04/12] rcutorture: Make torture.sh --do-rt use CONFIG_PREEMPT_RT

From: Paul E. McKenney
Date: Sat Apr 05 2025 - 13:10:33 EST


On Sat, Apr 05, 2025 at 07:01:13AM -0400, Joel Fernandes wrote:
>
>
> On 4/2/2025 3:17 PM, Paul E. McKenney wrote:
> > On Wed, Apr 02, 2025 at 12:19:13PM -0400, Joel Fernandes wrote:
> >> Hello,
> >>
> >> On Wed, 2 Apr 2025 16:17:06 GMT, Sebastian Andrzej Siewior wrote:
> >>> On 2025-03-31 14:03:06 [-0700], Paul E. McKenney wrote:
> >>>> The torture.sh --do-rt command-line parameter is intended to mimic -rt
> >>>> kernels. Now that CONFIG_PREEMPT_RT is upstream, this commit makes this
> >>>> mimicking more precise.
> >>>>
> >>>> Note that testing of RCU priority boosting is disabled in favor
> >>>> of forward-progress testing of RCU callbacks. If it turns out to be
> >>>> possible to make kernels built with CONFIG_PREEMPT_RT=y to tolerate
> >>>> testing of both, both will be enabled.
> >>>
> >>> Not sure what you point at here: You can build a PREEMPT_RT kernel and
> >>> RCU boosting is enabled by default. You could disable it if needed.
> >>
> >> Yeah, RCU_BOOST has default y if PREEMPT_RT.
> >>
> >> Paul, should we be disabling it in the --do-rt script?
> >
> > You should have a "rcutorture.test_boost=0" from f2ac55968df2
> > ("rcutorture: Make torture.sh --do-rt use CONFIG_PREEMPT_RT").
> >
> > Plus I just now made additional adjustments based on Sebastian Siewior's
> > feedback. He is likely to have additional feedback, so this is currently
> > a "squash!" commit in my tree.
> Ok, thanks. If you could repost whenever it is ready to the list, I'll pull it.

If there are no complaints by Monday, Pacific Time, I will resend it.

> Also I'm guessing that checkpatch one does not need any changes, but we've to
> add a reminder to revert it in the future.

I have added a reminder in my usual todo.txt file. I have no objection
to it being added to a more visible location. On possible place would
be the RCU Design Documents gdoc, but I will let you guys choose.

Thanx, Paul