On Fri, 26 Jul 2019 16:54:11 +0200 Peter Zijlstra <pet...@infradead.org> wrote:
> Make sure the entire for loop has stop_cpus_in_progress set. > kernel/stop_machine.c | 2 ++ > 1 file changed, 2 insertions(+) > > --- a/kernel/stop_machine.c > +++ b/kernel/stop_machine.c > @@ -383,6 +383,7 @@ static bool queue_stop_cpus_work(const s > */ > preempt_disable(); > stop_cpus_in_progress = true; > + barrier(); Like smp_mb() shouldn't barrier() have a comment to what is being ordered and why? -- Steve > for_each_cpu(cpu, cpumask) { > work = &per_cpu(cpu_stopper.stop_work, cpu); > work->fn = fn; > @@ -391,6 +392,7 @@ static bool queue_stop_cpus_work(const s > if (cpu_stop_queue_work(cpu, work)) > queued = true; > } > + barrier(); > stop_cpus_in_progress = false; > preempt_enable(); > >