[Intel-wired-lan] [next-queue 3/3] i40e: Add i40e_napi_poll tracepoint

[Joe Damato <jdamato@fastly.com>]

Add a tracepoint for i40e_napi_poll that allows users to get detailed
information about the amount of work done. This information can help users
better tune the correct NAPI parameters (like weight and budget), as well
as debug NIC settings like rx-usecs and tx-usecs, etc.

An example of the output from this tracepoint:

[...snip...]

1029.268 :0/0 i40e:i40e_napi_poll(i40e_napi_poll on dev eth1 q i40e-eth1-TxRx-30 irq 172 irq_mask 00000000,00000000,00000000,00000010,00000000,00000000 curr_cpu 68 budget 64 bpr 64 work_done 0 tx_work_done 2 clean_complete 1 tx_clean_complete 1)
	i40e_napi_poll ([i40e])
	i40e_napi_poll ([i40e])
	__napi_poll ([kernel.kallsyms])
	net_rx_action ([kernel.kallsyms])
	__do_softirq ([kernel.kallsyms])
	common_interrupt ([kernel.kallsyms])
	asm_common_interrupt ([kernel.kallsyms])
	intel_idle_irq ([kernel.kallsyms])
	cpuidle_enter_state ([kernel.kallsyms])
	cpuidle_enter ([kernel.kallsyms])
	do_idle ([kernel.kallsyms])
	cpu_startup_entry ([kernel.kallsyms])
	[0x243fd8] ([kernel.kallsyms])
	secondary_startup_64_no_verify ([kernel.kallsyms])

Signed-off-by: Joe Damato <jdamato@fastly.com>
---
 drivers/net/ethernet/intel/i40e/i40e_trace.h | 50 ++++++++++++++++++++++++++++
 drivers/net/ethernet/intel/i40e/i40e_txrx.c  |  3 ++
 2 files changed, 53 insertions(+)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_trace.h b/drivers/net/ethernet/intel/i40e/i40e_trace.h
index b5b1229..779d046 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_trace.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_trace.h
@@ -55,6 +55,56 @@
  * being built from shared code.
  */
 
+#define NO_DEV "(i40e no_device)"
+
+TRACE_EVENT(i40e_napi_poll,
+
+	TP_PROTO(struct napi_struct *napi, struct i40e_q_vector *q, int budget,
+		 int budget_per_ring, int work_done, int tx_work_done, bool clean_complete,
+		 bool tx_clean_complete),
+
+	TP_ARGS(napi, q, budget, budget_per_ring, work_done, tx_work_done,
+		clean_complete, tx_clean_complete),
+
+	TP_STRUCT__entry(
+		__field(int, budget)
+		__field(int, budget_per_ring)
+		__field(int, work_done)
+		__field(int, tx_work_done)
+		__field(int, clean_complete)
+		__field(int, tx_clean_complete)
+		__field(int, irq_num)
+		__field(int, curr_cpu)
+		__string(qname, q->name)
+		__string(dev_name, napi->dev ? napi->dev->name : NO_DEV)
+		__bitmask(irq_affinity,	nr_cpumask_bits)
+	),
+
+	TP_fast_assign(
+		__entry->budget = budget;
+		__entry->budget_per_ring = budget_per_ring;
+		__entry->work_done = work_done;
+		__entry->tx_work_done = tx_work_done;
+		__entry->clean_complete = clean_complete;
+		__entry->tx_clean_complete = tx_clean_complete;
+		__entry->irq_num = q->irq_num;
+		__entry->curr_cpu = get_cpu();
+		__assign_str(qname, q->name);
+		__assign_str(dev_name, napi->dev ? napi->dev->name : NO_DEV);
+		__assign_bitmask(irq_affinity, cpumask_bits(&q->affinity_mask),
+				 nr_cpumask_bits);
+	),
+
+	TP_printk("i40e_napi_poll on dev %s q %s irq %d irq_mask %s curr_cpu %d "
+		  "budget %d bpr %d work_done %d tx_work_done %d "
+		  "clean_complete %d tx_clean_complete %d",
+		__get_str(dev_name), __get_str(qname), __entry->irq_num,
+		__get_bitmask(irq_affinity), __entry->curr_cpu, __entry->budget,
+		__entry->budget_per_ring, __entry->work_done,
+		__entry->tx_work_done,
+		__entry->clean_complete, __entry->tx_clean_complete)
+);
+
 /* Events related to a vsi & ring */
 DECLARE_EVENT_CLASS(
 	i40e_tx_template,
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index ed88309..8b72f1b 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -2743,6 +2743,9 @@ int i40e_napi_poll(struct napi_struct *napi, int budget)
 			clean_complete = false;
 	}
 
+	trace_i40e_napi_poll(napi, q_vector, budget, budget_per_ring, work_done, tx_wd,
+			     clean_complete, tx_clean_complete);
+
 	/* If work not completed, return budget and polling will return */
 	if (!clean_complete || !tx_clean_complete) {
 		int cpu_id = smp_processor_id();
-- 
2.7.4

_______________________________________________
Intel-wired-lan mailing list
Intel-wired-lan@osuosl.org
https://lists.osuosl.org/mailman/listinfo/intel-wired-lan