diff mbox series

[next-queue,3/3] i40e: Add i40e_napi_poll tracepoint

Message ID 1664958703-4224-4-git-send-email-jdamato@fastly.com
State Superseded
Headers show
Series i40e: Add an i40e_napi_poll tracepoint | expand

Commit Message

Joe Damato Oct. 5, 2022, 8:31 a.m. UTC
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(+)

Comments

Maciej Fijalkowski Oct. 5, 2022, 10:27 a.m. UTC | #1
On Wed, Oct 05, 2022 at 01:31:43AM -0700, Joe Damato wrote:

Hi Joe,

> 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])

maybe you could also include how to configure this tracepoint for future
readers?

> 
> 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;

What if rx clean routines failed to do allocation of new rx bufs? then
this would be misinterpreted. maybe we should change the API to

static bool
i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget,
		  unsigned int *processed_pkts);

so you would return failure and at the end do
	*processed_pkts = total_rx_packets;

then also i would change the naming of tracepoint entry. I'm not a native
english speaker but having 'done' within the variable name suggests to me
that it is rather a boolean. what about something like 'rx_cleaned_pkts'
instead?

Generally I think this is useful, personally I was in need of tracing the
next_to_clean and next_to_use ring indexes a lot, but that is probably out
of the scope in here.

> +		__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
>
Joe Damato Oct. 5, 2022, 5:56 p.m. UTC | #2
On Wed, Oct 05, 2022 at 12:27:30PM +0200, Maciej Fijalkowski wrote:
> On Wed, Oct 05, 2022 at 01:31:43AM -0700, Joe Damato wrote:
> 
> Hi Joe,
> 
> > 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])
> 
> maybe you could also include how to configure this tracepoint for future
> readers?

Ah, for some reason I deleted that line from the commit message. Will
include it in the v2.

> > 
> > 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;
> 
> What if rx clean routines failed to do allocation of new rx bufs? then
> this would be misinterpreted. maybe we should change the API to
> 
> static bool
> i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget,
> 		  unsigned int *processed_pkts);
> 
> so you would return failure and at the end do
> 	*processed_pkts = total_rx_packets;

I reworked i40e_clean_rx_irq and i40e_clean_rx_irq_zc to do what you've
described -- this is also how I ended up approaching counting TX cleaned.

> 
> then also i would change the naming of tracepoint entry. I'm not a native
> english speaker but having 'done' within the variable name suggests to me
> that it is rather a boolean. what about something like 'rx_cleaned_pkts'
> instead?

Sure, I've changed the trace prototype, struct, and print statement to use
"rx_cleaned" and "tx_cleaned" instead of "work_done" and "tx_work_done".

>
> Generally I think this is useful, personally I was in need of tracing the
> next_to_clean and next_to_use ring indexes a lot, but that is probably out
> of the scope in here.

Yea, I've used those for debugging other things, as well - they are quite
useful, but I agree... I think that's out of scope for this set :)

Thank you very much for all your detailed feedback. Hopefully the v2 will
be a bit closer.

> > +		__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
> >
diff mbox series

Patch

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();