Re: Question about ->head field of rcu_segcblist

[Joel Fernandes]

On Sun, Sep 23, 2018 at 7:30 PM Joel Fernandes <joel@xxxxxxxxxxxxxxxxx> wrote:
>
> Hi Paul,
>
> I was parsing the Data-Structures document and had a question about
> the following "Important note" text.
>
> Could it be clarified in the below text better why "remaining
> callbacks are placed back on the RCU_DONE_TAIL segment", is a reason
> for not depending on ->head for determining if no callbacks are
> associated with the rcu_segcblist? If callbacks are added back to the
> DONE_TAIL segment, then I would think rcu_head should be != NULL.
> Infact the "rsclp->head = *rsclp->tails[RCU_DONE_TAIL];" in
> rcu_segcblist_extract_done_cbs should set the ->head to  NULL if I
> understand correctly.

Just to clarify, I meant set to NULL assuming all cbs were done
waiting and ready to be invoked.