On Tue, Sep 13, 2016 at 12:03:05PM +0800, Cheng Chao wrote: > > Peter, Is it as a new patch?
I wanted both changes in one pathc, but I fudged my git-diff. > > --- > > kernel/stop_machine.c | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c > > index ae6f41fb9cba..637798d6b554 100644 > > --- a/kernel/stop_machine.c > > +++ b/kernel/stop_machine.c > > @@ -121,6 +121,11 @@ int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, > > void *arg) > > cpu_stop_init_done(&done, 1); > > if (!cpu_stop_queue_work(cpu, &work)) > > return -ENOENT; > > + /* > > + * In case @cpu == smp_proccessor_id() we can avoid a sleep+wakeup > > + * by doing a preemption. > > + */ > > + cond_resched(); > > wait_for_completion(&done.completion); > > return done.ret; > > } > > > > I agree to use cond_resched(). https://lkml.org/lkml/2016/9/12/1228 > > so we really don't need "if defined(CONFIG_PREEMPT_NONE)"? > I also think without the "if defined(CONFIG_PREEMPT_NONE)", > the code is more clean,and the logic is still ok. You really don't need the #ifdef, look at the actual code, not the Kconfig language.
