| From | Valentin Schneider <> | Subject | Re: [RFC PATCH v2 16/20] rcu: Make RCU dynticks counter size configurable | Date | Fri, 21 Jul 2023 09:17:53 +0100 |
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On 20/07/23 17:30, Valentin Schneider wrote: > index bdd7eadb33d8f..1ff2aab24e964 100644 > --- a/kernel/rcu/Kconfig > +++ b/kernel/rcu/Kconfig > @@ -332,4 +332,37 @@ config RCU_DOUBLE_CHECK_CB_TIME > Say Y here if you need tighter callback-limit enforcement. > Say N here if you are unsure. > > +config RCU_DYNTICKS_RANGE_BEGIN > + int > + depends on !RCU_EXPERT > + default 31 if !CONTEXT_TRACKING_WORK
You'll note that this should be 30 really, because the lower *2* bits are taken by the context state (CONTEXT_GUEST has a value of 3).
This highlights the fragile part of this: the Kconfig values are hardcoded, but they depend on CT_STATE_SIZE, CONTEXT_MASK and CONTEXT_WORK_MAX. The static_assert() will at least capture any misconfiguration, but having that enforced by the actual Kconfig ranges would be less awkward.
Do we currently have a way of e.g. making a Kconfig file depend on and use values generated by a C header?
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