Messages in this thread | | | Date | Mon, 22 Jun 2020 19:29:36 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH][v2] PM / s2idle: Clear _TIF_POLLING_NRFLAG before suspend to idle |
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On Mon, Jun 22, 2020 at 06:19:35PM +0200, Rafael J. Wysocki wrote: > > Fixes: b2a02fc43a1f ("smp: Optimize send_call_function_single_ipi()") > > Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> > > Reported-by: kbuild test robot <lkp@intel.com> > > Cc: "Rafael J. Wysocki" <rafael@kernel.org> > > Cc: Len Brown <lenb@kernel.org> > > Cc: Peter Zijlstra (Intel) <peterz@infradead.org> > > Signed-off-by: Chen Yu <yu.c.chen@intel.com> > > Peter, any more comments here?
Only that the whole s2idle stuff could do with a cleanup :-)
> > +static int call_s2idle(struct cpuidle_driver *drv, struct cpuidle_device *dev, > > + int index) > > +{ > > + if (!current_clr_polling_and_test()) > > + s2idle_enter(drv, dev, index); > > + > > + return index; > > Is the value returned here used at all? > > > +} > > + > > /** > > * cpuidle_enter_s2idle - Enter an idle state suitable for suspend-to-idle. > > * @drv: cpuidle driver for the given CPU. > > @@ -187,7 +197,7 @@ int cpuidle_enter_s2idle(struct cpuidle_driver *drv, struct cpuidle_device *dev) > > */ > > index = find_deepest_state(drv, dev, U64_MAX, 0, true); > > if (index > 0) > > - enter_s2idle_proper(drv, dev, index); > > + call_s2idle(drv, dev, index); > > I'm wondering why this can't be > > if (index > 0 && !current_clr_polling_and_test()) > enter_s2idle_proper(drv, dev, index);
Works for me. Some Wysocki guy wrote much of it, best ask him :-)
The thing that confused me is that all this is way different from the normal idle path and didn't keep the invariants.
Ideally; much of that gets folded back into the normal patch somehow.
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