Re: [vpp-dev] How to get source node of a buffer
See URL below. The vpp packet dispatch tracer will show you everything you would want to know about the nodes visited by individual packets: https://fd.io/docs/vpp/master/gettingstarted/developers/vnet.html#graph-dispatcher-pcap-tracing This is a developer tool, not a tool for post-mortem analysis. HTH... Dave From: vpp-dev@lists.fd.io On Behalf Of Neale Ranns via Lists.Fd.Io Sent: Tuesday, March 24, 2020 4:06 AM To: Satya Murthy ; vpp-dev@lists.fd.io Cc: vpp-dev@lists.fd.io Subject: Re: [vpp-dev] How to get source node of a buffer Hi Murthy, There is no way to get the source node. However, if you are debugging and you want to see the full history of the graph through which a packet has passed, you can turn on trajectory tracing. #define VLIB_BUFFER_TRACE_TRAJECTORY 1 In vlib/buffer.h /neale From: mailto:vpp-dev@lists.fd.io>> on behalf of Satya Murthy mailto:satyamurthy1...@gmail.com>> Date: Tuesday 24 March 2020 at 06:44 To: "vpp-dev@lists.fd.io<mailto:vpp-dev@lists.fd.io>" mailto:vpp-dev@lists.fd.io>> Subject: [vpp-dev] How to get source node of a buffer Hi , Is there any way to find the source node of a buffer. Basically, I want to know from which node this buffer came. I understand that each graph node shall have a design which is independant of the source node. However, the source node information may be useful in case of debugging some crashes while processing a buffer. Any inputs on this pls. -- Thanks & Regards, Murthy -=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#15852): https://lists.fd.io/g/vpp-dev/message/15852 Mute This Topic: https://lists.fd.io/mt/72511630/21656 Group Owner: vpp-dev+ow...@lists.fd.io Unsubscribe: https://lists.fd.io/g/vpp-dev/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
Re: [vpp-dev] How to get source node of a buffer
Thanks Neale for the quick inputs. I am planning to add src_node index in the buffer metadata ( opaque2) for this purpose. Hoping that this helps in our debugging. -- Thanks & Regards, Murthy -=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#15850): https://lists.fd.io/g/vpp-dev/message/15850 Mute This Topic: https://lists.fd.io/mt/72511630/21656 Group Owner: vpp-dev+ow...@lists.fd.io Unsubscribe: https://lists.fd.io/g/vpp-dev/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
Re: [vpp-dev] How to get source node of a buffer
> There is no way to get the source node. > However, if you are debugging and you want to see the full history of the > graph through which a packet has passed, you can turn on trajectory > tracing. > #define VLIB_BUFFER_TRACE_TRAJECTORY 1 > In vlib/buffer.h One issue I ran into you must be aware of is if buffer cloning happens you end up with 2 buffers using the same trajectory vector pointer in opaque2 - this did not ended well. I spent some time tracking all cloning to try to fix it w/o success in the past. Another technique which does not require recompiling is to enable buffer traces and dump to stderr from gdb with 'call (void)gdb_show_traces()' but you'll have to enable it for each source node to identify the culprit... ben > From: on behalf of Satya Murthy > > Date: Tuesday 24 March 2020 at 06:44 > To: "vpp-dev@lists.fd.io" > Subject: [vpp-dev] How to get source node of a buffer > > > > Hi , > > Is there any way to find the source node of a buffer. Basically, I want to > know from which node this buffer came. > I understand that each graph node shall have a design which is independant > of the source node. > However, the source node information may be useful in case of debugging > some crashes while processing a buffer. > > Any inputs on this pls. > > -- > Thanks & Regards, > Murthy -=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#15849): https://lists.fd.io/g/vpp-dev/message/15849 Mute This Topic: https://lists.fd.io/mt/72511630/21656 Group Owner: vpp-dev+ow...@lists.fd.io Unsubscribe: https://lists.fd.io/g/vpp-dev/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
Re: [vpp-dev] How to get source node of a buffer
Hi Murthy, There is no way to get the source node. However, if you are debugging and you want to see the full history of the graph through which a packet has passed, you can turn on trajectory tracing. #define VLIB_BUFFER_TRACE_TRAJECTORY 1 In vlib/buffer.h /neale From: on behalf of Satya Murthy Date: Tuesday 24 March 2020 at 06:44 To: "vpp-dev@lists.fd.io" Subject: [vpp-dev] How to get source node of a buffer Hi , Is there any way to find the source node of a buffer. Basically, I want to know from which node this buffer came. I understand that each graph node shall have a design which is independant of the source node. However, the source node information may be useful in case of debugging some crashes while processing a buffer. Any inputs on this pls. -- Thanks & Regards, Murthy -=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#15848): https://lists.fd.io/g/vpp-dev/message/15848 Mute This Topic: https://lists.fd.io/mt/72511630/21656 Group Owner: vpp-dev+ow...@lists.fd.io Unsubscribe: https://lists.fd.io/g/vpp-dev/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
[vpp-dev] How to get source node of a buffer
Hi , Is there any way to find the source node of a buffer. Basically, I want to know from which node this buffer came. I understand that each graph node shall have a design which is independant of the source node. However, the source node information may be useful in case of debugging some crashes while processing a buffer. Any inputs on this pls. -- Thanks & Regards, Murthy -=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#15846): https://lists.fd.io/g/vpp-dev/message/15846 Mute This Topic: https://lists.fd.io/mt/72511630/21656 Group Owner: vpp-dev+ow...@lists.fd.io Unsubscribe: https://lists.fd.io/g/vpp-dev/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
