| Date | Tue, 7 May 2024 15:48:18 +0200 | From | Frederic Weisbecker <> | Subject | Re: [PATCH v2 18/27] rcu: Rename rcu_dynticks_in_eqs_since() into rcu_watching_changed_since() |
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Le Tue, Apr 30, 2024 at 11:17:22AM +0200, Valentin Schneider a écrit : > The context_tracking.state RCU_DYNTICKS subvariable has been renamed to > RCU_WATCHING, the dynticks prefix can go. > > Furthermore, the "in_eqs_since" part confuses me, as IIUC this only checks > for a change in watching/eqs state, not that RCU transitionned *into* a > EQS after the snapshot was taken. > > e.g. if > snap = 0b1000 (EQS) > and the following rcu_watching_snap(CPU) is: > 0b1100 (watching) > then > rcu_watching_in_eqs_since(rdp, snap) -> true > > but because RCU was already in EQS at the time of the > snap - it hasn't entered EQS "since" the snap was taken. > > Update the name to reflect that we're only looking at watching/EQS > transitions, not specifically transitions into EQS.
Indeed in practice the function only checks a change. But semantically it really checks a trip to eqs because this function is only ever called after a failing call to rcu_dynticks_in_eqs().
So not sure about that one rename. Paul?
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