irqbalance on HT capable PE4600?
jason at rtfmconsult.com
Sat Oct 18 17:20:00 CDT 2003
On Sat, 18 Oct 2003, Arjan van de Ven wrote:
i'm continuing to CC this to the PE list as i assume it'll be useful
for someone down the track for performance tuning information assuming
Arjan continues to reply :-)
> First of all; several network cards have ways of
> reducing the irq rate via so called interrupt mitigation; this is not
> always enabled since it CAN reduce network performance
> on low-use networking.
the current network is gigE which is pushing around 100-140Mbit/sec on
an Intel Pro/1000. it is anticipated this may need to double over the
next year. my own testing of the pro/1000 is that you can achieve full
line rate gigE on the card (if the machine is doing nothing else) so
i'm pretty confident it can handle 300-400Mbit/sec in normal operation.
however i need to try to do some more work to see why the current
config spends 70-80% of time in 'system' - i assume a chunk of that
is the nfsd but wanted to make sure there wasn't other things i'd
been overlooking previously (like the irq rate)
> For example, e1000 has several module parameters to enable this:
> parm: TxIntDelay description "Transmit Interrupt Delay"
> parm: TxAbsIntDelay description "Transmit Absolute Interrupt Delay"
> parm: RxIntDelay description "Receive Interrupt Delay"
> parm: RxAbsIntDelay description "Receive Absolute Interrupt Delay"
> setting these values to > 0 (eg somewhere between 2 and 10) will
> probably reduce your rate of interrupts quite significant (and
> increase performance due to better irq grouping)
the server in question is a NFS server so i'd definitely like to
improve performance (but not obviously at the cost of serving
less bytes to the front end boxes). i'll do some testing with
> Another thing you can do is install the RHL8 erratum or RHL9
> kernel-utils rpm and make sure the irqbalance service is started during
> boot (default for RHL9, the RHL8 erratum defaults to off)
(i assume the values below have wrapped)
8:17am up 59 days, 18:59, 5 users, load average: 11.25, 11.44, 12.11
0: 1322107066 1322871970 IO-APIC-edge timer
1: 273 264 IO-APIC-edge keyboard
2: 0 0 XT-PIC cascade
8: 0 1 IO-APIC-edge rtc
16: 253487196 253651272 IO-APIC-level eth0
20: 799452491 799875894 IO-APIC-level qla2200
22: 2366882687 2368370608 IO-APIC-level qla2200
24: 1316729851 1317548294 IO-APIC-level qla2200
26: 1147601730 1148380357 IO-APIC-level eth2
28: 959647645 1005132173 IO-APIC-level eth1
30: 2022 1991 IO-APIC-level aic7xxx
31: 518955144 519175867 IO-APIC-level aacraid
NMI: 0 0
LOC: 2645057853 2645057854
i am looking at replacing the current box (PE2400 w/ 2 933 P3s w/ 1G ram w/ RH7.3)
with a dual xeon P4/2.4 w/ 4G of ram and using RHEL 3 on it.
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