[LibreQoS] Fwd: [next-queue v4 4/4] i40e: Add i40e_napi_poll tracepoint

[Dave Taht]

---------- Forwarded message ---------
From: Joe Damato <jdamato at fastly.com>
Date: Fri, Oct 7, 2022, 2:43 PM
Subject: [next-queue v4 4/4] i40e: Add i40e_napi_poll tracepoint
To: <intel-wired-lan at lists.osuosl.org>
Cc: <netdev at vger.kernel.org>, <kuba at kernel.org>, <davem at davemloft.net>, <
anthony.l.nguyen at intel.com>, <jesse.brandeburg at intel.com>, <
maciej.fijalkowski at intel.com>, <sridhar.samudrala at intel.com>, Joe Damato <
jdamato at 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.

When perf is attached, this tracepoint only fires when not in XDP mode.

An example of the output from this tracepoint:

$ sudo perf trace -e i40e:i40e_napi_poll -a --call-graph=fp
--libtraceevent_print

[..snip..]

388.258 :0/0 i40e:i40e_napi_poll(i40e_napi_poll on dev eth2 q
i40e-eth2-TxRx-9 irq 346 irq_mask
00000000,00000000,00000000,00000000,00000000,00800000 curr_cpu 23 budget 64
bpr 64 rx_cleaned 28 tx_cleaned 0 rx_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 at fastly.com>
Acked-by: Jesse Brandeburg <jesse.brandeburg at intel.com>
Acked-by: Sridhar Samudrala <sridhar.samudrala at intel.com>
---
 drivers/net/ethernet/intel/i40e/i40e_trace.h | 49
++++++++++++++++++++++++++++
 drivers/net/ethernet/intel/i40e/i40e_txrx.c  |  4 +++
 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..79d587a 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_trace.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_trace.h
@@ -55,6 +55,55 @@
  * 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, unsigned int rx_cleaned, unsigned int
tx_cleaned,
+                bool rx_clean_complete, bool tx_clean_complete),
+
+       TP_ARGS(napi, q, budget, budget_per_ring, rx_cleaned, tx_cleaned,
+               rx_clean_complete, tx_clean_complete),
+
+       TP_STRUCT__entry(
+               __field(int, budget)
+               __field(int, budget_per_ring)
+               __field(unsigned int, rx_cleaned)
+               __field(unsigned int, tx_cleaned)
+               __field(int, rx_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->rx_cleaned = rx_cleaned;
+               __entry->tx_cleaned = tx_cleaned;
+               __entry->rx_clean_complete = rx_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 rx_cleaned %u tx_cleaned %u "
+                 "rx_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->rx_cleaned,
__entry->tx_cleaned,
+               __entry->rx_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 5901e58..f2b1b94 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -2752,6 +2752,10 @@ int i40e_napi_poll(struct napi_struct *napi, int
budget)
                        clean_complete = rx_clean_complete = false;
        }

+       if (!i40e_enabled_xdp_vsi(vsi))
+               trace_i40e_napi_poll(napi, q_vector, budget,
budget_per_ring, rx_cleaned,
+                                    tx_cleaned, rx_clean_complete,
tx_clean_complete);
+
        /* If work not completed, return budget and polling will return */
        if (!clean_complete) {
                int cpu_id = smp_processor_id();
-- 
2.7.4
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