Messages in this thread | | | Date | Wed, 14 Dec 2022 16:04:33 -0800 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH RFC] srcu: Yet more detail for srcu_readers_active_idx_check() comments |
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On Wed, Dec 14, 2022 at 11:14:48PM +0000, Joel Fernandes wrote: > On Wed, Dec 14, 2022 at 11:10 PM Joel Fernandes <joel@joelfernandes.org> wrote: > > > > On Wed, Dec 14, 2022 at 11:07 PM Joel Fernandes <joel@joelfernandes.org> wrote: > > > > > > On Wed, Dec 14, 2022 at 9:24 PM Paul E. McKenney <paulmck@kernel.org> wrote: > > > > > I also did not get why you care about readers that come and ago (you > > > > > mentioned the first reader seeing incorrect idx and the second reader > > > > > seeing the right flipped one, etc). Those readers are irrelevant > > > > > AFAICS since they came and went, and need not be waited on , right?. > > > > > > > > The comment is attempting to show (among other things) that we don't > > > > need to care about readers that come and go more than twice during that > > > > critical interval of time during the counter scans. > > > > > > Why do we need to care about readers that come and go even once? Once > > > they are gone, they have already done an unlock() and their RSCS is > > > over, so they need to be considered AFAICS. > > > > > > > Aargh, I meant: "so they need to be considered AFAICS". > > Trying again: "so they need not be considered AFAICS".
Give or take counter wrap, which can make it appear that still-present readers have finished.
> Anyway, my 1 year old son is sick so signing off for now. Thanks.
Ouch! I hope he recovers quickly and completely!!!
Thanx, Paul
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