[opensuse] High interrupt rates (was about network interface overruns)
I wrote:
I'm testing a new fibre connection at 50/10Mbit, and the network interface card is showing an increasing number of overruns when I "stress" the link with a lengthy download from a high-speed source. In the last 4Gb download, I saw the counter increase by at least 10000.
Googling has informed me that "Receive overruns means that packets are arriving faster than you can receive". The firewall to which the fibre is connected is an elderly PIII 800MHz, but I can't quite imagine that causing this issue.
If you've followed the previous thread about network interface overruns, you will know that switching to a different network card didn't quite solve the problem, but it did significantly reduce the number of overruns. As Google suggested, it seems quite clear that the machine simply could not deal with the flow of interrupts, which was also evident in the slowing of the system clock! As far as I can tell, the clock was slowed down due to the system being unable to process the clock interrupt in a timely manner. Or is there another reason why the system clock would slow down during periods of many interrupts? Not just a few seconds, more than 1000s over e.g. 25-30mins. The question now remains - can this system be tuned/tweaked to process network interrupts better/faster? Any applicable kernel parameters? It is a dedicated firewall/router box with a PIII 800MHz and 512Mb RAM. The currently installed oS is 11.0 with kernel 2.6.25.5. -- Per Jessen, Zürich (10.1°C) -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
El 04/04/12 13:45, Per Jessen escribió:
The question now remains - can this system be tuned/tweaked to process network interrupts better/faster? Any applicable kernel parameters? It is a dedicated firewall/router box with a PIII 800MHz and 512Mb RAM. The currently installed oS is 11.0 with kernel 2.6.25.5.
While this is probably just that your hardware is too old, please try with a more recent kernel, I believe kernel-default from -stable repo will install in 11.0 -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
Cristian Rodríguez wrote:
El 04/04/12 13:45, Per Jessen escribió:
The question now remains - can this system be tuned/tweaked to process network interrupts better/faster? Any applicable kernel parameters? It is a dedicated firewall/router box with a PIII 800MHz and 512Mb RAM. The currently installed oS is 11.0 with kernel 2.6.25.5.
While this is probably just that your hardware is too old, please try with a more recent kernel, I believe kernel-default from -stable repo will install in 11.0
Yeah, I'm working on that just now. I agree the hardware is old, but the 800MHz clock-frequency is much higher than what would be needed to switch a mere 50Mbit/s. -- Per Jessen, Zürich (10.5°C) -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
Per Jessen wrote:
Cristian Rodríguez wrote:
El 04/04/12 13:45, Per Jessen escribió:
The question now remains - can this system be tuned/tweaked to process network interrupts better/faster? Any applicable kernel parameters? It is a dedicated firewall/router box with a PIII 800MHz and 512Mb RAM. The currently installed oS is 11.0 with kernel 2.6.25.5.
While this is probably just that your hardware is too old, please try with a more recent kernel, I believe kernel-default from -stable repo will install in 11.0
Yeah, I'm working on that just now.
I upgraded the kernel to 3.3.0-2-default a couple of days ago, then upgraded iptables due to some incompatiblity. Since then I have been trying to get my test setup to work again - afaict, there is a problem with iptables masquerading. I can't get it to work (same firewall/iptables setup) with kernel 3.3.0, but it worked fine with the much older 2.6.25. Others seem to think so too: http://ask.fedoraproject.org/question/1429/port-forwarding-with-kernel-330-n... I'm now pondering rolling back my iptables upgrades and running the firewall (on upgraded hardware) with the old kernel again. A bit annoying, but I have only so much time to test this new fibre-link before the meter starts ticking. Alternatively, can anyone point me to a slightly older 3.x kernel where iptables masquerading _does_ work? -- Per Jessen, Zürich (4.0°C) -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
Per Jessen wrote:
Per Jessen wrote:
Cristian Rodríguez wrote:
El 04/04/12 13:45, Per Jessen escribió:
The question now remains - can this system be tuned/tweaked to process network interrupts better/faster? Any applicable kernel parameters? It is a dedicated firewall/router box with a PIII 800MHz and 512Mb RAM. The currently installed oS is 11.0 with kernel 2.6.25.5.
While this is probably just that your hardware is too old, please try with a more recent kernel, I believe kernel-default from -stable repo will install in 11.0
Yeah, I'm working on that just now.
I upgraded the kernel to 3.3.0-2-default a couple of days ago, then upgraded iptables due to some incompatiblity. Since then I have been trying to get my test setup to work again - afaict, there is a problem with iptables masquerading. I can't get it to work (same firewall/iptables setup) with kernel 3.3.0, but it worked fine with the much older 2.6.25. Others seem to think so too:
http://ask.fedoraproject.org/question/1429/port-forwarding-with-kernel-330-n...
And this one: http://www.fedoraforum.de/viewtopic.php?f=6&p=124882 "Port forwarding (nat) geht seit Kernel 3.3 nicht mehr". -- Per Jessen, Zürich (3.9°C) -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
Per Jessen wrote:
I wrote:
The question now remains - can this system be tuned/tweaked to process network interrupts better/faster? Any applicable kernel parameters?
After some experimenting with newer kernels, I ended up going back to my starting point (kernel 2.6.25), except for a newer version of iptables (had to upgrade to work with kernel 3.3.0). Miraculously, the number of network interface overruns has now dropped to virtually nothing even under full network load. ssh access is even working with normal response times. Is it likely that the newer version of iptables (from factory) could have this kind of impact? -- Per Jessen, Zürich (7.6°C) -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
participants (2)
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Cristian Rodríguez -
Per Jessen