[E1000-devel] igb 2.1.1 increased ping times on 82571EB

[amnon c. <amn...@go...>]

Hi,
I have upgraded my igb driver from version  1.3.16-k2 (kernel.org) to 2.1.1
from sourceforge.
Ping times to a neighboring machine have increased from

rtt min/avg/max/mdev = 0.043/0.045/0.047/0.004 ms

to
rtt min/avg/max/mdev = 0.052/0.055/0.065/0.002 ms

The new driver was loaded with command line arguments I
nterruptThrottleRate=0,0,0,0

Any ideas where these extra 10us of latency come from?

Other info:
Kernel version: 2.6.32

lspci -vv output:


01:00.1 Ethernet controller: Intel Corporation 82575EB Gigabit Network
Connection (rev 02)
        Subsystem: Sun Microsystems Computer Corp. Device 0000
        Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr+
Stepping- SERR+ FastB2B- DisINTx+
        Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort-
<TAbort- <MAbort- >SERR- <PERR- INTx-
        Latency: 0, Cache Line Size: 64 bytes
        Interrupt: pin B routed to IRQ 40
        Region 0: Memory at fa9e0000 (32-bit, non-prefetchable) [size=128K]
        Region 1: Memory at fa9c0000 (32-bit, non-prefetchable) [size=128K]
        Region 2: I/O ports at ac00 [size=32]
        Region 3: Memory at fa9bc000 (32-bit, non-prefetchable) [size=16K]
        Expansion ROM at fa980000 [disabled] [size=128K]
        Capabilities: [40] Power Management version 2
                Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA
PME(D0+,D1-,D2-,D3hot+,D3cold+)
                Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=1 PME-
        Capabilities: [50] MSI: Enable- Count=1/1 Maskable- 64bit+
                Address: 0000000000000000  Data: 0000
        Capabilities: [60] MSI-X: Enable+ Count=10 Masked-
                Vector table: BAR=3 offset=00000000
                PBA: BAR=3 offset=00002000
        Capabilities: [a0] Express (v2) Endpoint, MSI 00
                DevCap: MaxPayload 256 bytes, PhantFunc 0, Latency L0s
<512ns, L1 <64us
                        ExtTag- AttnBtn- AttnInd- PwrInd- RBE+ FLReset-
                DevCtl: Report errors: Correctable+ Non-Fatal+ Fatal+
Unsupported-
                        RlxdOrd+ ExtTag- PhantFunc- AuxPwr- NoSnoop+
                        MaxPayload 128 bytes, MaxReadReq 512 bytes
                DevSta: CorrErr+ UncorrErr- FatalErr- UnsuppReq+ AuxPwr+
TransPend-
                LnkCap: Port #0, Speed 2.5GT/s, Width x2, ASPM L0s L1,
Latency L0 <4us, L1 <64us
                        ClockPM- Surprise- LLActRep- BwNot-
                LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- Retrain-
CommClk+
                        ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
                LnkSta: Speed 2.5GT/s, Width x2, TrErr- Train- SlotClk+
DLActive- BWMgmt- ABWMgmt-
                DevCap2: Completion Timeout: Range ABCD, TimeoutDis+
                DevCtl2: Completion Timeout: 16ms to 55ms, TimeoutDis-
                LnkCtl2: Target Link Speed: 2.5GT/s, EnterCompliance-
SpeedDis-, Selectable De-emphasis: -6dB
                         Transmit Margin: Normal Operating Range,
EnterModifiedCompliance- ComplianceSOS-
                         Compliance De-emphasis: -6dB
                LnkSta2: Current De-emphasis Level: -6dB
        Kernel driver in use: igb
        Kernel modules: igb

Thanks,
   Amnon