Messages in this thread | | | Date | Fri, 6 Aug 2021 20:20:49 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH] notifier: Make atomic_notifiers use raw_spinlock |
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On Fri, Aug 06, 2021 at 08:06:53PM +0200, Sebastian Andrzej Siewior wrote: > On 2021-08-06 20:02:42 [+0200], Peter Zijlstra wrote: > > On Fri, Aug 06, 2021 at 04:07:18PM +0200, Sebastian Andrzej Siewior wrote: > > > What do we do with this? > > > Do we merge this as-is, add another "robust atomic notifier" using only > > > raw_spinlock_t for registration and notification (for only > > > cpu_pm_notifier_chain) instead of switching to raw_spinlock_t for all > > > atomic notifier in -tree? > > > > Right, so the problem I see with this is that > > notifier_chain_{,un}register() are O(n). Hardly something we should be > > putting under raw_spin_lock :/ > > Yup, pretty much. So we make one robust notifier for > cpu_pm_notifier_chain?
Yeah, I suppose so :-( Ideally that whole pm notifier thing goes, but that's *far* more work and I really don't want to be responsible for the brain damange resulting from looking at all that 'special' idle code.
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