On Tue, Oct 03, 2023 at 08:21:42PM -0700, Paul E. McKenney wrote:
> On Tue, Oct 03, 2023 at 05:35:31PM -0700, Paul E. McKenney wrote:
> > On Wed, Oct 04, 2023 at 01:28:58AM +0200, Frederic Weisbecker wrote:
> > > Hi,
> > >
> > > This contains a fix for "SRCU: kworker hung in synchronize_srcu":
> > >
> > >
> > > http://lore.kernel.org/CANZk6aR+CqZaqmMWrC2eRRPY12qAZnDZLwLnHZbNi=xxmb4...@mail.gmail.com
> > >
> > > And a few cleanups.
> > >
> > > Passed 50 hours of SRCU-P and SRCU-N.
> > >
> > > git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git
> > > srcu/fixes
> > >
> > > HEAD: 7ea5adc5673b42ef06e811dca75e43d558cc87e0
> > >
> > > Thanks,
> > > Frederic
> >
> > Very good, and a big "Thank You!!!" to all of you!
> >
> > I queued this series for testing purposes, and have started a bunch of
> > SRCU-P and SRCU-N tests on one set of systems, and a single SRCU-P and
> > SRCU-N on another system, but with both scenarios resized to 40 CPU each.
The 200*1h of SRCU-N and the 100*1h of SRCU-p passed other than the usual
tick-stop errors. (Is there a patch for that one?) The 40-CPU SRCU-N
run was fine, but the 40-CPU SRCU-P run failed due to the fanouts setting
a maximum of 16 CPUs. So I started a 10-hour 40-CPU SRCU-P and a pair
of 10-hour 16-CPU SRCU-N runs on one system, and 200*10h of SRCU-N and
100*10h of SRCU-P.
I will let you know how it goes.
Thanx, Paul
> > While that is in flight, a few questions:
> >
> > o Please check the Co-developed-by rules. Last I knew, it was
> > necessary to have a Signed-off-by after each Co-developed-by.
> >
> > o Is it possible to get a Tested-by from the original reporter?
> > Or is this not reproducible?
> >
> > o Is it possible to convince rcutorture to find this sort of
> > bug? Seems like it should be, but easy to say...
>
> And one other thing...
>
> o What other bugs like this one are hiding elsewhere
> in RCU?
>
> > o Frederic, would you like to include this in your upcoming
> > pull request? Or does it need more time?
>
> Thanx, Paul
>
> > > ---
> > >
> > > Frederic Weisbecker (5):
> > > srcu: Fix callbacks acceleration mishandling
> > > srcu: Only accelerate on enqueue time
> > > srcu: Remove superfluous callbacks advancing from srcu_start_gp()
> > > srcu: No need to advance/accelerate if no callback enqueued
> > > srcu: Explain why callbacks invocations can't run concurrently
> > >
> > >
> > > kernel/rcu/srcutree.c | 55
> > > ++++++++++++++++++++++++++++++++++++---------------
> > > 1 file changed, 39 insertions(+), 16 deletions(-)
