From ce412fd7d644a21db9f0a170b88084223b7ee0fe Mon Sep 17 00:00:00 2001 From: Dave Barach Date: Tue, 2 Jun 2020 08:57:36 -0400 Subject: docs: improve handoff queue writeup Type: docs Signed-off-by: Dave Barach Change-Id: I4d63a0fbbdb3cc00eac9116f122e5b831d059e33 --- docs/gettingstarted/developers/vlib.md | 196 +++++++++++++++++++++++++++++++++ 1 file changed, 196 insertions(+) diff --git a/docs/gettingstarted/developers/vlib.md b/docs/gettingstarted/developers/vlib.md index 504ee07a7a0..13844ab455a 100644 --- a/docs/gettingstarted/developers/vlib.md +++ b/docs/gettingstarted/developers/vlib.md @@ -645,3 +645,199 @@ enqueue node by freeing dropped packets, or by pushing them to "error-drop." Either of those actions would be a severe error. * It's perfectly OK to enqueue packets to the current thread. + +Handoff Demo Plugin +------------------- + +Check out the sample (plugin) example in +.../src/examples/handoffdemo. If you want to build the handoff demo plugin: + +``` +$ cd .../src/plugins +$ ln -s ../examples/handoffdemo +``` + +This plugin provides a simple example of how to hand off packets +between threads. We used it to debug packet-tracer handoff tracing +support. + +# Packet generator input script + +``` + packet-generator new { + name x + limit 5 + size 128-128 + interface local0 + node handoffdemo-1 + data { + incrementing 30 + } + } +``` +# Start vpp with 2 worker threads + +The demo plugin hands packets from worker 1 to worker 2. + +# Enable tracing, and start the packet generator + +``` + trace add pg-input 100 + packet-generator enable +``` + +# Sample Run + +``` + DBGvpp# ex /tmp/pg_input_script + DBGvpp# pa en + DBGvpp# sh err + Count Node Reason + 5 handoffdemo-1 packets handed off processed + 5 handoffdemo-2 completed packets + DBGvpp# show run + Thread 1 vpp_wk_0 (lcore 0) + Time 133.9, average vectors/node 5.00, last 128 main loops 0.00 per node 0.00 + vector rates in 3.7331e-2, out 0.0000e0, drop 0.0000e0, punt 0.0000e0 + Name State Calls Vectors Suspends Clocks Vectors/Call + handoffdemo-1 active 1 5 0 4.76e3 5.00 + pg-input disabled 2 5 0 5.58e4 2.50 + unix-epoll-input polling 22760 0 0 2.14e7 0.00 + --------------- + Thread 2 vpp_wk_1 (lcore 2) + Time 133.9, average vectors/node 5.00, last 128 main loops 0.00 per node 0.00 + vector rates in 0.0000e0, out 0.0000e0, drop 3.7331e-2, punt 0.0000e0 + Name State Calls Vectors Suspends Clocks Vectors/Call + drop active 1 5 0 1.35e4 5.00 + error-drop active 1 5 0 2.52e4 5.00 + handoffdemo-2 active 1 5 0 2.56e4 5.00 + unix-epoll-input polling 22406 0 0 2.18e7 0.00 +``` + +Enable the packet tracer and run it again... + +``` + DBGvpp# trace add pg-input 100 + DBGvpp# pa en + DBGvpp# sh trace + sh trace + ------------------- Start of thread 0 vpp_main ------------------- + No packets in trace buffer + ------------------- Start of thread 1 vpp_wk_0 ------------------- + Packet 1 + + 00:06:50:520688: pg-input + stream x, 128 bytes, 0 sw_if_index + current data 0, length 128, buffer-pool 0, ref-count 1, trace handle 0x1000000 + 00000000: 000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d0000 + 00000020: 0000000000000000000000000000000000000000000000000000000000000000 + 00000040: 0000000000000000000000000000000000000000000000000000000000000000 + 00000060: 0000000000000000000000000000000000000000000000000000000000000000 + 00:06:50:520762: handoffdemo-1 + HANDOFFDEMO: current thread 1 + + Packet 2 + + 00:06:50:520688: pg-input + stream x, 128 bytes, 0 sw_if_index + current data 0, length 128, buffer-pool 0, ref-count 1, trace handle 0x1000001 + 00000000: 000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d0000 + 00000020: 0000000000000000000000000000000000000000000000000000000000000000 + 00000040: 0000000000000000000000000000000000000000000000000000000000000000 + 00000060: 0000000000000000000000000000000000000000000000000000000000000000 + 00:06:50:520762: handoffdemo-1 + HANDOFFDEMO: current thread 1 + + Packet 3 + + 00:06:50:520688: pg-input + stream x, 128 bytes, 0 sw_if_index + current data 0, length 128, buffer-pool 0, ref-count 1, trace handle 0x1000002 + 00000000: 000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d0000 + 00000020: 0000000000000000000000000000000000000000000000000000000000000000 + 00000040: 0000000000000000000000000000000000000000000000000000000000000000 + 00000060: 0000000000000000000000000000000000000000000000000000000000000000 + 00:06:50:520762: handoffdemo-1 + HANDOFFDEMO: current thread 1 + + Packet 4 + + 00:06:50:520688: pg-input + stream x, 128 bytes, 0 sw_if_index + current data 0, length 128, buffer-pool 0, ref-count 1, trace handle 0x1000003 + 00000000: 000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d0000 + 00000020: 0000000000000000000000000000000000000000000000000000000000000000 + 00000040: 0000000000000000000000000000000000000000000000000000000000000000 + 00000060: 0000000000000000000000000000000000000000000000000000000000000000 + 00:06:50:520762: handoffdemo-1 + HANDOFFDEMO: current thread 1 + + Packet 5 + + 00:06:50:520688: pg-input + stream x, 128 bytes, 0 sw_if_index + current data 0, length 128, buffer-pool 0, ref-count 1, trace handle 0x1000004 + 00000000: 000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d0000 + 00000020: 0000000000000000000000000000000000000000000000000000000000000000 + 00000040: 0000000000000000000000000000000000000000000000000000000000000000 + 00000060: 0000000000000000000000000000000000000000000000000000000000000000 + 00:06:50:520762: handoffdemo-1 + HANDOFFDEMO: current thread 1 + + ------------------- Start of thread 2 vpp_wk_1 ------------------- + Packet 1 + + 00:06:50:520796: handoff_trace + HANDED-OFF: from thread 1 trace index 0 + 00:06:50:520796: handoffdemo-2 + HANDOFFDEMO: current thread 2 + 00:06:50:520867: error-drop + rx:local0 + 00:06:50:520914: drop + handoffdemo-2: completed packets + + Packet 2 + + 00:06:50:520796: handoff_trace + HANDED-OFF: from thread 1 trace index 1 + 00:06:50:520796: handoffdemo-2 + HANDOFFDEMO: current thread 2 + 00:06:50:520867: error-drop + rx:local0 + 00:06:50:520914: drop + handoffdemo-2: completed packets + + Packet 3 + + 00:06:50:520796: handoff_trace + HANDED-OFF: from thread 1 trace index 2 + 00:06:50:520796: handoffdemo-2 + HANDOFFDEMO: current thread 2 + 00:06:50:520867: error-drop + rx:local0 + 00:06:50:520914: drop + handoffdemo-2: completed packets + + Packet 4 + + 00:06:50:520796: handoff_trace + HANDED-OFF: from thread 1 trace index 3 + 00:06:50:520796: handoffdemo-2 + HANDOFFDEMO: current thread 2 + 00:06:50:520867: error-drop + rx:local0 + 00:06:50:520914: drop + handoffdemo-2: completed packets + + Packet 5 + + 00:06:50:520796: handoff_trace + HANDED-OFF: from thread 1 trace index 4 + 00:06:50:520796: handoffdemo-2 + HANDOFFDEMO: current thread 2 + 00:06:50:520867: error-drop + rx:local0 + 00:06:50:520914: drop + handoffdemo-2: completed packets + DBGvpp# +``` -- cgit 1.2.3-korg