Re: [BUG] ixgbe: something wrong with queue selection ?

Jeff Kirsher
2012-04-17T09:16:28Z

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On Tue, 2012-04-17 at 11:06 +0200, Eric Dumazet wrote:
> Hi guys
>
> I have bad feelings with ixgbe and its multiqueue selection.
>
> On a quad core machine (Q6600), I get lots of reorderings on a single
> TCP stream.
>
>
> Apparently packets happily spread on all available queues, instead of a
> single one.
>
> This defeats GRO at receiver and TCP performance is really bad.
>
> # ethtool -S eth5|egrep "x_queue_[0123]_packets" ; taskset 1 netperf -H
> 192.168.99.1 ; ethtool -S eth5|egrep "x_queue_[0123]_packets"
> tx_queue_0_packets: 24
> tx_queue_1_packets: 26
> tx_queue_2_packets: 32
> tx_queue_3_packets: 16
> rx_queue_0_packets: 11
> rx_queue_1_packets: 47
> rx_queue_2_packets: 27
> rx_queue_3_packets: 22
> MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to
> 192.168.99.1 (192.168.99.1) port 0 AF_INET
> Recv Send Send
> Socket Socket Message Elapsed
> Size Size Size Time Throughput
> bytes bytes bytes secs. 10^6bits/sec
>
> 87380 16384 16384 10.00 3866.43
> tx_queue_0_packets: 1653201
> tx_queue_1_packets: 608000
> tx_queue_2_packets: 541382
> tx_queue_3_packets: 536543
> rx_queue_0_packets: 434703
> rx_queue_1_packets: 137444
> rx_queue_2_packets: 131023
> rx_queue_3_packets: 128407
>
> # ip ro get 192.168.99.1
> 192.168.99.1 dev eth5 src 192.168.99.2
> cache ipid 0x438b rtt 4ms rttvar 4ms cwnd 57 reordering 127
>
> # lspci -v -s 02:00.0
> 02:00.0 Ethernet controller: Intel Corporation 82599EB 10-Gigabit
> SFI/SFP+ Network Connection (rev 01)
> Subsystem: Intel Corporation Ethernet Server Adapter X520-2
> Flags: bus master, fast devsel, latency 0, IRQ 16
> Memory at f1100000 (64-bit, prefetchable) [size=512K]
> I/O ports at b000 [size=32]
> Memory at f1200000 (64-bit, prefetchable) [size=16K]
> Capabilities: [40] Power Management version 3
> Capabilities: [50] MSI: Enable- Count=1/1 Maskable+ 64bit+
> Capabilities: [70] MSI-X: Enable+ Count=64 Masked-
> Capabilities: [a0] Express Endpoint, MSI 00
> Capabilities: [100] Advanced Error Reporting
> Capabilities: [140] Device Serial Number 00-1b-21-ff-ff-4a-fe-54
> Capabilities: [150] Alternative Routing-ID Interpretation (ARI)
> Capabilities: [160] Single Root I/O Virtualization (SR-IOV)
> Kernel driver in use: ixgbe
> Kernel modules: ixgbe
>
>

Adding Don Skidmore and Alex Duyck...

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