On Tue, Oct 16, 2018 at 08:31:14AM +0200, Christian Ludwig wrote:
> Do not roll a custom for-loop, use the appropriate TAILQ function.
>
> Also use unsleep() instead of coding the same functionality here again.
> There is only one place in the system that resets p_wchan now. And the
> unsleep-part has the same pattern like in endtsleep().
> ---
> sys/kern/kern_synch.c | 12 +++++-------
> 1 file changed, 5 insertions(+), 7 deletions(-)
>
> diff --git a/sys/kern/kern_synch.c b/sys/kern/kern_synch.c
> index 684624428db..154686e924b 100644
> --- a/sys/kern/kern_synch.c
> +++ b/sys/kern/kern_synch.c
> @@ -436,15 +436,13 @@ unsleep(struct proc *p)
> void
> wakeup_n(const volatile void *ident, int n)
> {
> - struct slpque *qp;
> struct proc *p;
> - struct proc *pnext;
> int s;
>
> SCHED_LOCK(s);
> - qp = &slpque[LOOKUP(ident)];
> - for (p = TAILQ_FIRST(qp); p != NULL && n != 0; p = pnext) {
> - pnext = TAILQ_NEXT(p, p_runq);
> + TAILQ_FOREACH(p, &slpque[LOOKUP(ident)], p_runq) {
> + if (n == 0)
> + break;
I have big doubts about this change. There is a TAILQ_REMOVE inside this
loop so using TAILQ_FOREACH() is not right.
> #ifdef DIAGNOSTIC
> /*
> * If the rwlock passed to rwsleep() is contended, the
> @@ -460,10 +458,10 @@ wakeup_n(const volatile void *ident, int n)
> #endif
> if (p->p_wchan == ident) {
> --n;
> - p->p_wchan = 0;
> - TAILQ_REMOVE(qp, p, p_runq);
> if (p->p_stat == SSLEEP)
> setrunnable(p);
> + else
> + unsleep(p);
> }
> }
> SCHED_UNLOCK(s);
> --
> 2.19.0
>
--
:wq Claudio
