On Wed, 19 Dec 2007 08:23:43 +0100
Eric Dumazet <[EMAIL PROTECTED]> wrote:
> Stephen Hemminger a écrit :
> > The neighbor GC timer runs once a second, but it doesn't need to wake
> > up the machine.
> >
> > Signed-off-by: Stephen Hemminger <[EMAIL PROTECTED]>
> >
> > --- a/net/core/neighbour.c 2007-12-18 07:46:07.000000000 -0800
> > +++ b/net/core/neighbour.c 2007-12-18 07:47:36.000000000 -0800
> > @@ -270,7 +270,7 @@ static struct neighbour *neigh_alloc(str
> > n->nud_state = NUD_NONE;
> > n->output = neigh_blackhole;
> > n->parms = neigh_parms_clone(&tbl->parms);
> > - init_timer(&n->timer);
> > + init_timer_deferrable(&n->timer);
> > n->timer.function = neigh_timer_handler;
> > n->timer.data = (unsigned long)n;
> >
> > @@ -740,7 +740,7 @@ static void neigh_timer_handler(unsigned
> >
> > state = neigh->nud_state;
> > now = jiffies;
> > - next = now + HZ;
> > + next = round_jiffies(now + HZ);
> >
> > if (!(state & NUD_IN_TIMER)) {
> > #ifndef CONFIG_SMP
> > @@ -1372,7 +1372,7 @@ void neigh_table_init_no_netlink(struct
> > get_random_bytes(&tbl->hash_rnd, sizeof(tbl->hash_rnd));
> >
> > rwlock_init(&tbl->lock);
> > - init_timer(&tbl->gc_timer);
> > + init_timer_deferrable(&tbl->gc_timer);
> > tbl->gc_timer.data = (unsigned long)tbl;
> > tbl->gc_timer.function = neigh_periodic_timer;
> > tbl->gc_timer.expires = now + 1;
>
> I wonder if this deferrable timer thing is the right way to go.
>
> (like read_mostly thing if you want :) )
>
> We are going to convert 99% timers to deferrable.
>
> Maybe the right move should be to have the reverse attribute, to mark a timer
> as non deferrable...
>
> Also, why use round_jiffies() on a deferrable timer ? That sounds unecessary ?
Thinking about it more, this looks like a case for just using round_jiffies().
The GC timer needs to run to clean up under DoS attack, and deferring it
probably
isn't a good idea.
--
Stephen Hemminger <[EMAIL PROTECTED]>
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