On Tue, Jun 14, 2016 at 08:05:49PM +0200, Thomas Gleixner wrote:
> On Tue, 14 Jun 2016, Arjan van de Ven wrote:
>
> > evaluating a 120 hours timer ever 37 hours to see if it should fire...
> > not too horrid.
>
> Well that thing is doing weird stuff anyway:
>
> swapper 0 [001] 1789995.305532: timer:timer_start:
> timer=0xffff8800c8346920 function=death_by_timeout expires=4850639994
> [timeout=108000000]
You're running a HZ=250 kernel, right?
inet/netfilter/nf_conntrack_proto_tcp.c:
#define SECS * HZ
#define MINS * 60 SECS
#define HOURS * 60 MINS
#define DAYS * 24 HOURS
static unsigned int tcp_timeouts[TCP_CONNTRACK_TIMEOUT_MAX] __read_mostly = {
[TCP_CONNTRACK_SYN_SENT] = 2 MINS,
[TCP_CONNTRACK_SYN_RECV] = 60 SECS,
[TCP_CONNTRACK_ESTABLISHED] = 5 DAYS,
^^^^^^ that
ends up being 108000000 for HZ == 250.
[TCP_CONNTRACK_FIN_WAIT] = 2 MINS,
[TCP_CONNTRACK_CLOSE_WAIT] = 60 SECS,
[TCP_CONNTRACK_LAST_ACK] = 30 SECS,
[TCP_CONNTRACK_TIME_WAIT] = 2 MINS,
[TCP_CONNTRACK_CLOSE] = 10 SECS,
[TCP_CONNTRACK_SYN_SENT2] = 2 MINS,
/* RFC1122 says the R2 limit should be at least 100 seconds.
Linux uses 15 packets as limit, which corresponds
to ~13-30min depending on RTO. */
[TCP_CONNTRACK_RETRANS] = 5 MINS,
[TCP_CONNTRACK_UNACK] = 5 MINS,
};
> ssh 3870 [001] 1790025.284704: timer:timer_cancel:
> timer=0xffff8800c8346920
> ssh 3870 [001] 1790025.284707: timer:timer_start:
> timer=0xffff8800c8346920 function=death_by_timeout expires=4742722493
> [timeout=75000]
And that one would then be one of the 5 MINS ones.
