Hello,
Kain wrote:
> impossible 888
> divide error: 0000
> > > EIP; c024c5ea <fib_select_multipath+5a/a0> <=====
> Trace; c02232e8 <ip_route_output_slow+318/670>
There is no write locking in fib_select_multipath,
combined with high rate of route resolutions and ... boom,
fi->fib_power is 0:
w = jiffies % fi->fib_power;
What about a different algorithm to apply weighted
round robin (idea mostly from LVS), something like
this code (entirely not tested) where fi->fib_power is not used
and where fib_sync_up and fib_sync_down don't need to play
with nh_power on nh_flags change:
void fib_select_multipath(const struct rt_key *key, struct fib_result *res)
{
struct fib_info *fi = res->fi;
int w = -1, sel = 0;
write_lock(&fib_info_lock);
repeat:
change_nexthops(fi) {
if (nh->nh_power > w && !(nh->nh_flags&RTNH_F_DEAD)) {
w = nh->nh_power;
sel = nhsel;
}
} endfor_nexthops(fi);
if (w > 0) {
fi->fib_nh[sel].nh_power--;
write_unlock(&fib_info_lock);
res->nh_sel = sel;
return;
}
if (!w) {
change_nexthops(fi) {
if (!(nh->nh_flags&RTNH_F_DEAD)) {
nh->nh_power = nh->nh_weight;
}
} endfor_nexthops(fi);
w = -1;
goto repeat;
}
write_unlock(&fib_info_lock);
#if 1
printk(KERN_CRIT "impossible 888\n");
#endif
return;
}
Regards
-- Julian Anastasov <ja@ssi.bg>- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Thu Mar 07 2002 - 21:00:20 EST