lkml.org 
[lkml]   [2002]   [Mar]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectDropped packets on SUN GEM
From
Date
Hi David,

I've been running some more tests on the GEM card. It seems to be
recovering from the RX hangs ok, but when I ping another host on the
network (with a .1s interval).. I get the following


monkey:/home/andy# ping -s 1472 -i .1 10.0.0.15
PING 10.0.0.15 (10.0.0.15) from 10.0.0.12 : 1472(1500) bytes of data.
1480 bytes from 10.0.0.15: icmp_seq=1 ttl=255 time=0.586 ms
1480 bytes from 10.0.0.15: icmp_seq=2 ttl=255 time=0.554 ms
1480 bytes from 10.0.0.15: icmp_seq=3 ttl=255 time=0.561 ms
1480 bytes from 10.0.0.15: icmp_seq=4 ttl=255 time=0.565 ms
<snip>
1480 bytes from 10.0.0.15: icmp_seq=570 ttl=255 time=0.557 ms
1480 bytes from 10.0.0.15: icmp_seq=571 ttl=255 time=0.550 ms
1480 bytes from 10.0.0.15: icmp_seq=572 ttl=255 time=0.558 ms
1480 bytes from 10.0.0.15: icmp_seq=573 ttl=255 time=0.552 ms
1480 bytes from 10.0.0.15: icmp_seq=574 ttl=255 time=0.558 ms
1480 bytes from 10.0.0.15: icmp_seq=575 ttl=255 time=0.570 ms
1480 bytes from 10.0.0.15: icmp_seq=590 ttl=255 time=0.565 ms
1480 bytes from 10.0.0.15: icmp_seq=591 ttl=255 time=0.562 ms
1480 bytes from 10.0.0.15: icmp_seq=592 ttl=255 time=0.567 ms
1480 bytes from 10.0.0.15: icmp_seq=593 ttl=255 time=0.526 ms
1480 bytes from 10.0.0.15: icmp_seq=594 ttl=255 time=0.560 ms
1480 bytes from 10.0.0.15: icmp_seq=595 ttl=255 time=0.562 ms

notice the missing 14 packets.

Now, if I reproduce the test with a .2s interval between pings, I get
the following results.

monkey:/home/andy# ping -s 1472 -i .2 10.0.0.15
PING 10.0.0.15 (10.0.0.15) from 10.0.0.12 : 1472(1500) bytes of data.
1480 bytes from 10.0.0.15: icmp_seq=1 ttl=255 time=0.645 ms
1480 bytes from 10.0.0.15: icmp_seq=2 ttl=255 time=0.578 ms
1480 bytes from 10.0.0.15: icmp_seq=3 ttl=255 time=0.592 ms
1480 bytes from 10.0.0.15: icmp_seq=4 ttl=255 time=0.585 ms
1480 bytes from 10.0.0.15: icmp_seq=5 ttl=255 time=0.575 ms
1480 bytes from 10.0.0.15: icmp_seq=6 ttl=255 time=0.577 ms
<snip>
1480 bytes from 10.0.0.15: icmp_seq=292 ttl=255 time=0.564 ms
1480 bytes from 10.0.0.15: icmp_seq=293 ttl=255 time=0.559 ms
1480 bytes from 10.0.0.15: icmp_seq=294 ttl=255 time=0.568 ms
1480 bytes from 10.0.0.15: icmp_seq=295 ttl=255 time=0.561 ms
1480 bytes from 10.0.0.15: icmp_seq=310 ttl=255 time=0.588 ms
1480 bytes from 10.0.0.15: icmp_seq=311 ttl=255 time=0.568 ms
1480 bytes from 10.0.0.15: icmp_seq=312 ttl=255 time=0.572 ms
1480 bytes from 10.0.0.15: icmp_seq=313 ttl=255 time=0.576 ms
1480 bytes from 10.0.0.15: icmp_seq=314 ttl=255 time=0.569 ms

notice, 14 missing packets again.

I'm pretty confident (as confident I can be whilst doing a "watch -n1
ifconfig"!) that it's doing this *during* the RX hang recovery, so it
appears that the RX hang recovery is taking 15 packets-worth of time,
rather than a set period of time (as I would expect - incorrectly?).

Is this normal? - Because it seems the amount of time to recover from a
hang is inversely proportional to the amount of work it is doing, I am
able to artificially improve the "uptime" of the card by permanantly
running a ping -f <host> on the box!!

Cheers,

Beezly


[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2005-03-22 13:21    [from the cache]
©2003-2011 Jasper Spaans