| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <Yz1cEtPLzbPkBCtV@boxer>
Date: Wed, 5 Oct 2022 12:27:30 +0200
From: Maciej Fijalkowski <maciej.fijalkowski@...el.com>
To: Joe Damato <jdamato@...tly.com>
CC: <intel-wired-lan@...ts.osuosl.org>, <netdev@...r.kernel.org>,
<kuba@...nel.org>, <davem@...emloft.net>,
<anthony.l.nguyen@...el.com>, <jesse.brandeburg@...el.com>
Subject: Re: [next-queue 3/3] i40e: Add i40e_napi_poll tracepoint
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@...tly.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
>
Powered by blists - more mailing lists