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Message-ID: <36D9DB17C6DE9E40B059440DB8D95F52044F8EC9@orsmsx418.amr.corp.intel.com>
Date: Thu, 31 Jan 2008 09:20:12 -0800
From: "Brandeburg, Jesse" <jesse.brandeburg@...el.com>
To: "Carsten Aulbert" <carsten.aulbert@....mpg.de>
Cc: "Bruce Allen" <ballen@...vity.phys.uwm.edu>,
<netdev@...r.kernel.org>,
"Henning Fehrmann" <henning.fehrmann@....mpg.de>,
"Bruce Allen" <bruce.allen@....mpg.de>
Subject: RE: e1000 full-duplex TCP performance well below wire speed
Carsten Aulbert wrote:
> We are using MSI, /proc/interrupts look like:
> n0003:~# cat /proc/interrupts
> 378: 17234866 0 0 0 PCI-MSI-edge
> eth1
> 379: 129826 0 0 0 PCI-MSI-edge
> eth0
> (sorry for the line break).
>
> What we don't understand is why only core0 gets the interrupts, since
> the affinity is set to f:
> # cat /proc/irq/378/smp_affinity
> f
without CONFIG_IRQBALANCE set, and no irqbalance daemon running, this is
expected. Seems it is also dependent upon your system hardware.
> Right now, irqbalance is not running, though I can give it shot if
> people think this will make a difference.
probably won't make much of a difference if you only have a single
interrupt source generating interrupts. If you are using both adapters
simultaneously, please use smp_affinity or turn on irqbalance.
>> I would suggest you try TCP_RR with a command line something like
>> this: netperf -t TCP_RR -H <hostname> -C -c -- -b 4 -r 64K
>
> I did that and the results can be found here:
> https://n0.aei.uni-hannover.de/wiki/index.php/NetworkTest
seems something went wrong and all you ran was the 1 byte tests, where
it should have been 64K both directions (request/response).
> The results with netperf running like
> netperf -t TCP_STREAM -H <host> -l 20
> can be found here:
> https://n0.aei.uni-hannover.de/wiki/index.php/NetworkTestNetperf1
> I reran the tests with
> netperf -t <test> -H <host> -l 20 -c -C
> or in the case of TCP_RR with the suggested burst settings -b 4 -r 64k
I get:
TCP REQUEST/RESPONSE TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to foo
(134.134.3.121) port 0 AF_INET : first burst 4
Local /Remote
Socket Size Request Resp. Elapsed Trans. CPU CPU S.dem
S.dem
Send Recv Size Size Time Rate local remote local
remote
bytes bytes bytes bytes secs. per sec % S % S us/Tr
us/Tr
16384 87380 65536 65536 10.00 1565.34 14.17 27.18 362.220
347.243
16384 87380
>> Yes, InterruptThrottleRate=8000 means there will be no more than 8000
>> ints/second from that adapter, and if interrupts are generated faster
>> than that they are "aggregated."
>>
>> Interestingly since you are interested in ultra low latency, and may
>> be willing to give up some cpu for it during bulk transfers you
>> should try InterruptThrottleRate=1 (can generate up to 70000 ints/s)
>>
>
> On the web page you'll see that there are about 4000 interrupts/s for
> most tests and up to 20,000/s for the TCP_RR test. Shall I change the
> throttle rate?
that's the auto-tuning, I suggest just InterruptThrottleRate=4000 or
8000 if all you're concerned about is bulk traffic performance.
>>>> just for completeness can you post the dump of ethtool -e eth0 and
>>>> lspci -vvv?
>>> Yup, we'll give that info also.
>
> n0002:~# ethtool -e eth1
> Offset Values
> ------ ------
> 0x0000 00 30 48 93 94 2d 20 0d 46 f7 57 00 ff ff ff ff
> 0x0010 ff ff ff ff 6b 02 9a 10 d9 15 9a 10 86 80 df 80
> 0x0020 00 00 00 20 54 7e 00 00 00 10 da 00 04 00 00 27
> 0x0030 c9 6c 50 31 32 07 0b 04 84 29 00 00 00 c0 06 07
> 0x0040 08 10 00 00 04 0f ff 7f 01 4d ff ff ff ff ff ff
> 0x0050 14 00 1d 00 14 00 1d 00 af aa 1e 00 00 00 1d 00
> 0x0060 00 01 00 40 1e 12 ff ff ff ff ff ff ff ff ff ff
> 0x0070 ff ff ff ff ff ff ff ff ff ff ff ff ff ff cf 2f
this looks fine.
> lspci -vvv for this card:
> 0e:00.0 Ethernet controller: Intel Corporation 82573L Gigabit Ethernet
> Controller
> Subsystem: Super Micro Computer Inc Unknown device 109a
> Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop-
> ParErr- Stepping- SERR+ FastB2B-
> Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast
> >TAbort- <TAbort- <MAbort- >SERR- <PERR-
> Latency: 0, Cache Line Size: 64 bytes
> Interrupt: pin A routed to IRQ 378
> Region 0: Memory at ee200000 (32-bit, non-prefetchable)
> [size=128K] Region 2: I/O ports at 5000 [size=32]
> Capabilities: [c8] Power Management version 2
> Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA
> PME(D0+,D1-,D2-,D3hot+,D3cold+)
> Status: D0 PME-Enable- DSel=0 DScale=1 PME-
> Capabilities: [d0] Message Signalled Interrupts: Mask- 64bit+
> Queue=0/0 Enable+
> Address: 00000000fee0f00c Data: 41b9
> Capabilities: [e0] Express Endpoint IRQ 0
> Device: Supported: MaxPayload 256 bytes, PhantFunc 0,
> ExtTag-
> Device: Latency L0s <512ns, L1 <64us
> Device: AtnBtn- AtnInd- PwrInd-
> Device: Errors: Correctable- Non-Fatal- Fatal-
> Unsupported- Device: RlxdOrd+ ExtTag- PhantFunc-
> AuxPwr- NoSnoop+ Device: MaxPayload 128 bytes,
> MaxReadReq 512 bytes Link: Supported Speed 2.5Gb/s,
> Width x1, ASPM unknown,
> Port 0
> Link: Latency L0s <128ns, L1 <64us
> Link: ASPM Disabled RCB 64 bytes CommClk- ExtSynch-
> Link: Speed 2.5Gb/s, Width x1
> Capabilities: [100] Advanced Error Reporting
> Capabilities: [140] Device Serial Number
> 2d-94-93-ff-ff-48-30-00
this also looks good, no APSM, MSI enabled,
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