Obtaining More Accurate Timestamps from simple_switch Logs for bmV2

Architecture Working Group
1

Hi,

Is there any way to get more accurate timestamps for the simple_switch logs?

For example, take a look at the logs below:

[16:24:38.133] [bmv2] [D] [thread 28315] [794.0] [cxt 0] Processing packet received on port 2
[16:24:38.133] [bmv2] [D] [thread 28315] [794.0] [cxt 0] Parser ‘parser’: start
[16:24:38.133] [bmv2] [D] [thread 28315] [794.0] [cxt 0] Parser ‘parser’ entering state ‘start’
[16:24:38.133] [bmv2] [D] [thread 28315] [794.0] [cxt 0] Extracting header ‘ethernet’
[16:24:38.133] [bmv2] [D] [thread 28315] [794.0] [cxt 0] Parser state ‘start’: key is 0027
[16:24:38.133] [bmv2] [T] [thread 28315] [794.0] [cxt 0] Bytes parsed: 14
[16:24:38.133] [bmv2] [D] [thread 28315] [794.0] [cxt 0] Parser ‘parser’: end
[16:24:38.133] [bmv2] [D] [thread 28315] [794.0] [cxt 0] Pipeline ‘ingress’: start
[16:24:38.133] [bmv2] [T] [thread 28315] [794.0] [cxt 0] Applying table ‘MyIngress.phy_forward’
[16:24:38.133] [bmv2] [D] [thread 28315] [794.0] [cxt 0] Looking up key:

  • standard_metadata.ingress_port: 0002

[16:24:38.133] [bmv2] [D] [thread 28315] [794.0] [cxt 0] Table ‘MyIngress.phy_forward’: hit with handle 0
[16:24:38.133] [bmv2] [D] [thread 28315] [794.0] [cxt 0] Dumping entry 0
Match key:

  • standard_metadata.ingress_port: EXACT 0002
    Action entry: MyIngress.forward - 1,

[16:24:38.133] [bmv2] [D] [thread 28315] [794.0] [cxt 0] Action entry is MyIngress.forward - 1,
[16:24:38.133] [bmv2] [T] [thread 28315] [794.0] [cxt 0] Action MyIngress.forward
[16:24:38.133] [bmv2] [T] [thread 28315] [794.0] [cxt 0] parsertest.p4(220) Primitive standard_metadata.egress_spec = port
[16:24:38.133] [bmv2] [D] [thread 28315] [794.0] [cxt 0] Pipeline ‘ingress’: end
[16:24:38.133] [bmv2] [D] [thread 28315] [794.0] [cxt 0] Egress port is 1
[16:24:38.133] [bmv2] [D] [thread 28317] [794.0] [cxt 0] Pipeline ‘egress’: start
[16:24:38.133] [bmv2] [D] [thread 28317] [794.0] [cxt 0] Pipeline ‘egress’: end
[16:24:38.133] [bmv2] [D] [thread 28317] [794.0] [cxt 0] Deparser ‘deparser’: start
[16:24:38.133] [bmv2] [D] [thread 28317] [794.0] [cxt 0] Deparsing header ‘ethernet’
[16:24:38.133] [bmv2] [D] [thread 28317] [794.0] [cxt 0] Deparser ‘deparser’: end
[16:24:38.133] [bmv2] [D] [thread 28320] [794.0] [cxt 0] Transmitting packet of size 60 out of port 1

As of now, each process of the bmv2 is timestamped to milliseconds. Is there any way to obtain much more accurate timestamps that is precise upto micro or nano seconds?

2

The only way I know to do this would be to modify the source code of BMv2, recompile it, and install that modified binary on your system.

3

Oh I see. Thank you very much. Are there any ongoing projects for making bmv2 production grade?

4

It depends on what you mean by “production grade”. If you mean “intended to forward packets in a production environment, as efficiently as any other software switch can do”, then I suspect the answer is “no”. There are significant development efforts being put right now into the open source p4c compiler’s DPDK back end, I believe with the intent of making it become useful in production scenarios.

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