David Gwynne([email protected]) on 2016.05.30 17:16:24 +1000:
> llinfo_nd6 thinks its expiry may extend beyond a timeout interval.
>
> so it keeps track of the number of ticks it really wants via ln_ntick
> in llinfo_nd6 and schedules multiple timeouts to reach it.
>
> i think this is a waste of time for two reasons:
>
> 1. nd6_llinfo_settimer() (which sets this up) doesnt seem to be
> called with a timeout greater than what timeouts can handle. timeouts
> off the wire are ignored if theyre greater than an hour
> (MAX_REACHABLE_TIME), and the largest constant that ends up being
> passed is a day via nd6_gctimer. the fastest ticking arch we have
> is alpha with HZ at 1024, which wraps at about 24 days. we have
> space.
>
> 2. ln_ntick is a long, which is the same size as int on 32 bit
> archs. the semantics it wants dont exist on a bunch of platforms.
> it is kind of arguing its own uselesness.
>
> ok?
sounds reasonable.
ok benno
>
> Index: nd6.c
> ===================================================================
> RCS file: /cvs/src/sys/netinet6/nd6.c,v
> retrieving revision 1.179
> diff -u -p -r1.179 nd6.c
> --- nd6.c 17 May 2016 08:29:14 -0000 1.179
> +++ nd6.c 30 May 2016 07:08:09 -0000
> @@ -308,21 +308,16 @@ nd6_llinfo_settimer(struct llinfo_nd6 *l
> {
> int s;
>
> + KASSERT(tick <= INT_MAX);
> +
> s = splsoftnet();
>
> if (tick < 0) {
> ln->ln_expire = 0;
> - ln->ln_ntick = 0;
> timeout_del(&ln->ln_timer_ch);
> } else {
> ln->ln_expire = time_second + tick / hz;
> - if (tick > INT_MAX) {
> - ln->ln_ntick = tick - INT_MAX;
> - timeout_add(&ln->ln_timer_ch, INT_MAX);
> - } else {
> - ln->ln_ntick = 0;
> - timeout_add(&ln->ln_timer_ch, tick);
> - }
> + timeout_add(&ln->ln_timer_ch, tick);
> }
>
> splx(s);
> @@ -341,18 +336,6 @@ nd6_llinfo_timer(void *arg)
> s = splsoftnet();
>
> ln = (struct llinfo_nd6 *)arg;
> -
> - if (ln->ln_ntick > 0) {
> - if (ln->ln_ntick > INT_MAX) {
> - ln->ln_ntick -= INT_MAX;
> - nd6_llinfo_settimer(ln, INT_MAX);
> - } else {
> - ln->ln_ntick = 0;
> - nd6_llinfo_settimer(ln, ln->ln_ntick);
> - }
> - splx(s);
> - return;
> - }
>
> if ((rt = ln->ln_rt) == NULL)
> panic("ln->ln_rt == NULL");
> Index: nd6.h
> ===================================================================
> RCS file: /cvs/src/sys/netinet6/nd6.h,v
> retrieving revision 1.58
> diff -u -p -r1.58 nd6.h
> --- nd6.h 30 Mar 2016 10:13:14 -0000 1.58
> +++ nd6.h 30 May 2016 07:08:09 -0000
> @@ -150,7 +150,6 @@ struct llinfo_nd6 {
> short ln_state; /* reachability state */
> short ln_router; /* 2^0: ND6 router bit */
>
> - long ln_ntick;
> struct timeout ln_timer_ch;
> };
>
>
--
