[v3,1/1] net/pcap: imissed stats support

Message ID 20210203230750.4499-1-ido@cgstowernetworks.com (mailing list archive)
State Superseded, archived
Delegated to: Ferruh Yigit
Headers
Series [v3,1/1] net/pcap: imissed stats support |

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/Intel-compilation success Compilation OK
ci/iol-broadcom-Functional success Functional Testing PASS
ci/intel-Testing success Testing PASS
ci/iol-broadcom-Performance success Performance Testing PASS
ci/iol-intel-Performance success Performance Testing PASS
ci/travis-robot warning Travis build: failed
ci/iol-testing warning Testing issues

Commit Message

Ido Goshen Feb. 3, 2021, 11:07 p.m. UTC
  get value from pcap_stats.ps_drop (see man pcap_stats)
the value is adjusted in this cases:
 - port stop - pcap is closed and will lose count
 - stats reset - pcap doesn't provide reset api
 - rollover - pcap counter size is u_32 only

Signed-off-by: Ido Goshen <ido@cgstowernetworks.com>
---
v3:
* code cleanup by dedicated struct and functions extraction
* multi stop support by menmonic+= accumulation
* rollover fixup

v2:
* sum all queues (rx_missed_total += fix)
* null pcap protection
* inter stop/start persistancy (counter won't reset on stop)

 drivers/net/pcap/rte_eth_pcap.c | 59 +++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)
  

Comments

Ferruh Yigit Feb. 4, 2021, 12:13 a.m. UTC | #1
On 2/3/2021 11:07 PM, Ido Goshen wrote:
> get value from pcap_stats.ps_drop (see man pcap_stats)
> the value is adjusted in this cases:
>   - port stop - pcap is closed and will lose count
>   - stats reset - pcap doesn't provide reset api
>   - rollover - pcap counter size is u_32 only
> 
> Signed-off-by: Ido Goshen <ido@cgstowernetworks.com>
> ---
> v3:
> * code cleanup by dedicated struct and functions extraction
> * multi stop support by menmonic+= accumulation
> * rollover fixup
> 
> v2:
> * sum all queues (rx_missed_total += fix)
> * null pcap protection
> * inter stop/start persistancy (counter won't reset on stop)
> 
>   drivers/net/pcap/rte_eth_pcap.c | 59 +++++++++++++++++++++++++++++++++
>   1 file changed, 59 insertions(+)
> 
> diff --git a/drivers/net/pcap/rte_eth_pcap.c b/drivers/net/pcap/rte_eth_pcap.c
> index a32b1f3f3..16e8752f3 100644
> --- a/drivers/net/pcap/rte_eth_pcap.c
> +++ b/drivers/net/pcap/rte_eth_pcap.c
> @@ -60,11 +60,21 @@ struct queue_stat {
>   	volatile unsigned long err_pkts;
>   };
>   
> +struct queue_missed_stat {
> +	/* last value retrieved from pcap */
> +	volatile unsigned int pcap;
> +	/* stores values lost by pcap stop or rollover */
> +	volatile unsigned long mnemonic;
> +	/* value on last reset */
> +	volatile unsigned long reset;
> +};

I am aware other stats has 'volatile' keyword, but as far as I can see it is not 
needed, since these are new ones can you please drop the 'volatile'?

> +
>   struct pcap_rx_queue {
>   	uint16_t port_id;
>   	uint16_t queue_id;
>   	struct rte_mempool *mb_pool;
>   	struct queue_stat rx_stat;
> +	struct queue_missed_stat missed_stat;
>   	char name[PATH_MAX];
>   	char type[ETH_PCAP_ARG_MAXLEN];
>   
> @@ -144,6 +154,49 @@ RTE_LOG_REGISTER(eth_pcap_logtype, pmd.net.pcap, NOTICE);
>   	rte_log(RTE_LOG_ ## level, eth_pcap_logtype, \
>   		"%s(): " fmt "\n", __func__, ##args)
>   
> +static struct queue_missed_stat*
> +queue_missed_stat_update(struct rte_eth_dev *dev, unsigned int qid)
> +{
> +	struct pmd_internals *internals = dev->data->dev_private;
> +	struct queue_missed_stat *missed_stat =
> +			&internals->rx_queue[qid].missed_stat;
> +	const struct pmd_process_private *pp = dev->process_private;
> +	pcap_t *pcap = pp->rx_pcap[qid];
> +	struct pcap_stat stat;

Can you please put an empty line after variable declarations, and before return.

> +	if (!pcap || (pcap_stats(pcap, &stat) != 0))
> +		return missed_stat;
> +	/* rollover check - best effort fixup assuming single rollover */
> +	if (stat.ps_drop < missed_stat->pcap)
> +		missed_stat->mnemonic += UINT_MAX;
> +	missed_stat->pcap = stat.ps_drop;

here.

> +	return missed_stat;
> +}
> +
> +static void
> +queue_missed_stat_on_stop_update(struct rte_eth_dev *dev, unsigned int qid)
> +{
> +	struct queue_missed_stat *missed_stat =
> +			queue_missed_stat_update(dev, qid);
> +	missed_stat->mnemonic += missed_stat->pcap;

Better to reset 'missed_stat->pcap' afterwards, in case stats requested before 
port started again:
  missed_stat->pcap = 0;

> +}
> +
> +static void
> +queue_missed_stat_reset(struct rte_eth_dev *dev, unsigned int qid)
> +{
> +	struct queue_missed_stat *missed_stat =
> +			queue_missed_stat_update(dev, qid);
> +	missed_stat->reset = missed_stat->pcap;

I guess this should be:
"missed_stat->reset = missed_stat->pcap + missed_stat->mnemonic;"

> +	missed_stat->mnemonic = 0;
> +}
> +
> +static unsigned long
> +queue_missed_stat_get(struct rte_eth_dev *dev, unsigned int qid)
> +{
> +	const struct queue_missed_stat *missed_stat =
> +			queue_missed_stat_update(dev, qid);
> +	return missed_stat->pcap + missed_stat->mnemonic - missed_stat->reset;
> +}
> +

<...>
  
Ido Goshen Feb. 4, 2021, 7:56 a.m. UTC | #2
> -----Original Message-----
> From: Ferruh Yigit <ferruh.yigit@intel.com>
> Sent: Thursday, 4 February 2021 2:13
> To: Ido Goshen <Ido@cgstowernetworks.com>
> Cc: dev@dpdk.org
> Subject: Re: [PATCH v3 1/1] net/pcap: imissed stats support
> 
> On 2/3/2021 11:07 PM, Ido Goshen wrote:
> > get value from pcap_stats.ps_drop (see man pcap_stats) the value is
> > adjusted in this cases:
> >   - port stop - pcap is closed and will lose count
> >   - stats reset - pcap doesn't provide reset api
> >   - rollover - pcap counter size is u_32 only
> >
> > Signed-off-by: Ido Goshen <ido@cgstowernetworks.com>
> > ---
> > v3:
> > * code cleanup by dedicated struct and functions extraction
> > * multi stop support by menmonic+= accumulation
> > * rollover fixup
> >
> > v2:
> > * sum all queues (rx_missed_total += fix)
> > * null pcap protection
> > * inter stop/start persistancy (counter won't reset on stop)
> >
> >   drivers/net/pcap/rte_eth_pcap.c | 59
> +++++++++++++++++++++++++++++++++
> >   1 file changed, 59 insertions(+)
> >
> > diff --git a/drivers/net/pcap/rte_eth_pcap.c
> > b/drivers/net/pcap/rte_eth_pcap.c index a32b1f3f3..16e8752f3 100644
> > --- a/drivers/net/pcap/rte_eth_pcap.c
> > +++ b/drivers/net/pcap/rte_eth_pcap.c
> > @@ -60,11 +60,21 @@ struct queue_stat {
> >   	volatile unsigned long err_pkts;
> >   };
> >
> > +struct queue_missed_stat {
> > +	/* last value retrieved from pcap */
> > +	volatile unsigned int pcap;
> > +	/* stores values lost by pcap stop or rollover */
> > +	volatile unsigned long mnemonic;
> > +	/* value on last reset */
> > +	volatile unsigned long reset;
> > +};
> 
> I am aware other stats has 'volatile' keyword, but as far as I can see it is not
> needed, since these are new ones can you please drop the 'volatile'?

ok 

> 
> > +
> >   struct pcap_rx_queue {
> >   	uint16_t port_id;
> >   	uint16_t queue_id;
> >   	struct rte_mempool *mb_pool;
> >   	struct queue_stat rx_stat;
> > +	struct queue_missed_stat missed_stat;
> >   	char name[PATH_MAX];
> >   	char type[ETH_PCAP_ARG_MAXLEN];
> >
> > @@ -144,6 +154,49 @@ RTE_LOG_REGISTER(eth_pcap_logtype,
> pmd.net.pcap, NOTICE);
> >   	rte_log(RTE_LOG_ ## level, eth_pcap_logtype, \
> >   		"%s(): " fmt "\n", __func__, ##args)
> >
> > +static struct queue_missed_stat*
> > +queue_missed_stat_update(struct rte_eth_dev *dev, unsigned int qid) {
> > +	struct pmd_internals *internals = dev->data->dev_private;
> > +	struct queue_missed_stat *missed_stat =
> > +			&internals->rx_queue[qid].missed_stat;
> > +	const struct pmd_process_private *pp = dev->process_private;
> > +	pcap_t *pcap = pp->rx_pcap[qid];
> > +	struct pcap_stat stat;
> 
> Can you please put an empty line after variable declarations, and before return.

ok

> 
> > +	if (!pcap || (pcap_stats(pcap, &stat) != 0))
> > +		return missed_stat;
> > +	/* rollover check - best effort fixup assuming single rollover */
> > +	if (stat.ps_drop < missed_stat->pcap)
> > +		missed_stat->mnemonic += UINT_MAX;
> > +	missed_stat->pcap = stat.ps_drop;
> 
> here.
> 
> > +	return missed_stat;
> > +}
> > +
> > +static void
> > +queue_missed_stat_on_stop_update(struct rte_eth_dev *dev, unsigned
> > +int qid) {
> > +	struct queue_missed_stat *missed_stat =
> > +			queue_missed_stat_update(dev, qid);
> > +	missed_stat->mnemonic += missed_stat->pcap;
> 
> Better to reset 'missed_stat->pcap' afterwards, in case stats requested before
> port started again:
>   missed_stat->pcap = 0;

right, should be careful not to double count it
but maybe better to set it to 0 in queue_missed_stat_update in the stop return case
	if (!pcap || (pcap_stats(pcap, &stat) != 0))
	{
		missed_stat->pcap = 0;
		return missed_stat;
	}
this way the missed_stat->pcap will always represent the current value from pcap and not hold old value
specifically in case port is stopped it will be 0 and not re-added 
agree?

> 
> > +}
> > +
> > +static void
> > +queue_missed_stat_reset(struct rte_eth_dev *dev, unsigned int qid) {
> > +	struct queue_missed_stat *missed_stat =
> > +			queue_missed_stat_update(dev, qid);
> > +	missed_stat->reset = missed_stat->pcap;
> 
> I guess this should be:
> "missed_stat->reset = missed_stat->pcap + missed_stat->mnemonic;"

I don't think so
reset should only remember where pcap was at the reset point and not store old values
trying it immediately results in

testpmd> show port stats 0

  ######################## NIC statistics for port 0  ########################
  RX-packets: 0          RX-missed: 1940       RX-bytes:  0
  RX-errors: 0
  RX-nombuf:  0         
  TX-packets: 0          TX-errors: 0          TX-bytes:  0

  Throughput (since last show)
  Rx-pps:            0          Rx-bps:            0
  Tx-pps:            0          Tx-bps:            0
  ############################################################################
testpmd> clear port stats 0

  NIC statistics for port 0 cleared
testpmd> show port stats 0

  ######################## NIC statistics for port 0  ########################
  RX-packets: 0          RX-missed: 18446744073709550646 RX-bytes:  0
  RX-errors: 0
  RX-nombuf:  0         
  TX-packets: 0          TX-errors: 0          TX-bytes:  0

  Throughput (since last show)
  Rx-pps:            0          Rx-bps:            0
  Tx-pps:            0          Tx-bps:            0
  ############################################################################

> > +	missed_stat->mnemonic = 0;
> > +}
> > +
> > +static unsigned long
> > +queue_missed_stat_get(struct rte_eth_dev *dev, unsigned int qid) {
> > +	const struct queue_missed_stat *missed_stat =
> > +			queue_missed_stat_update(dev, qid);
> > +	return missed_stat->pcap + missed_stat->mnemonic -
> > +missed_stat->reset; }
> > +
> 
> <...>
  
Ferruh Yigit Feb. 4, 2021, 9:26 a.m. UTC | #3
On 2/4/2021 7:56 AM, Ido Goshen wrote:
> 
> 
>> -----Original Message-----
>> From: Ferruh Yigit <ferruh.yigit@intel.com>
>> Sent: Thursday, 4 February 2021 2:13
>> To: Ido Goshen <Ido@cgstowernetworks.com>
>> Cc: dev@dpdk.org
>> Subject: Re: [PATCH v3 1/1] net/pcap: imissed stats support
>>
>> On 2/3/2021 11:07 PM, Ido Goshen wrote:
>>> get value from pcap_stats.ps_drop (see man pcap_stats) the value is
>>> adjusted in this cases:
>>>    - port stop - pcap is closed and will lose count
>>>    - stats reset - pcap doesn't provide reset api
>>>    - rollover - pcap counter size is u_32 only
>>>
>>> Signed-off-by: Ido Goshen <ido@cgstowernetworks.com>
>>> ---
>>> v3:
>>> * code cleanup by dedicated struct and functions extraction
>>> * multi stop support by menmonic+= accumulation
>>> * rollover fixup
>>>
>>> v2:
>>> * sum all queues (rx_missed_total += fix)
>>> * null pcap protection
>>> * inter stop/start persistancy (counter won't reset on stop)
>>>
>>>    drivers/net/pcap/rte_eth_pcap.c | 59
>> +++++++++++++++++++++++++++++++++
>>>    1 file changed, 59 insertions(+)
>>>
>>> diff --git a/drivers/net/pcap/rte_eth_pcap.c
>>> b/drivers/net/pcap/rte_eth_pcap.c index a32b1f3f3..16e8752f3 100644
>>> --- a/drivers/net/pcap/rte_eth_pcap.c
>>> +++ b/drivers/net/pcap/rte_eth_pcap.c
>>> @@ -60,11 +60,21 @@ struct queue_stat {
>>>    	volatile unsigned long err_pkts;
>>>    };
>>>
>>> +struct queue_missed_stat {
>>> +	/* last value retrieved from pcap */
>>> +	volatile unsigned int pcap;
>>> +	/* stores values lost by pcap stop or rollover */
>>> +	volatile unsigned long mnemonic;
>>> +	/* value on last reset */
>>> +	volatile unsigned long reset;
>>> +};
>>
>> I am aware other stats has 'volatile' keyword, but as far as I can see it is not
>> needed, since these are new ones can you please drop the 'volatile'?
> 
> ok
> 
>>
>>> +
>>>    struct pcap_rx_queue {
>>>    	uint16_t port_id;
>>>    	uint16_t queue_id;
>>>    	struct rte_mempool *mb_pool;
>>>    	struct queue_stat rx_stat;
>>> +	struct queue_missed_stat missed_stat;
>>>    	char name[PATH_MAX];
>>>    	char type[ETH_PCAP_ARG_MAXLEN];
>>>
>>> @@ -144,6 +154,49 @@ RTE_LOG_REGISTER(eth_pcap_logtype,
>> pmd.net.pcap, NOTICE);
>>>    	rte_log(RTE_LOG_ ## level, eth_pcap_logtype, \
>>>    		"%s(): " fmt "\n", __func__, ##args)
>>>
>>> +static struct queue_missed_stat*
>>> +queue_missed_stat_update(struct rte_eth_dev *dev, unsigned int qid) {
>>> +	struct pmd_internals *internals = dev->data->dev_private;
>>> +	struct queue_missed_stat *missed_stat =
>>> +			&internals->rx_queue[qid].missed_stat;
>>> +	const struct pmd_process_private *pp = dev->process_private;
>>> +	pcap_t *pcap = pp->rx_pcap[qid];
>>> +	struct pcap_stat stat;
>>
>> Can you please put an empty line after variable declarations, and before return.
> 
> ok
> 
>>
>>> +	if (!pcap || (pcap_stats(pcap, &stat) != 0))
>>> +		return missed_stat;
>>> +	/* rollover check - best effort fixup assuming single rollover */
>>> +	if (stat.ps_drop < missed_stat->pcap)
>>> +		missed_stat->mnemonic += UINT_MAX;
>>> +	missed_stat->pcap = stat.ps_drop;
>>
>> here.
>>
>>> +	return missed_stat;
>>> +}
>>> +
>>> +static void
>>> +queue_missed_stat_on_stop_update(struct rte_eth_dev *dev, unsigned
>>> +int qid) {
>>> +	struct queue_missed_stat *missed_stat =
>>> +			queue_missed_stat_update(dev, qid);
>>> +	missed_stat->mnemonic += missed_stat->pcap;
>>
>> Better to reset 'missed_stat->pcap' afterwards, in case stats requested before
>> port started again:
>>    missed_stat->pcap = 0;
> 
> right, should be careful not to double count it
> but maybe better to set it to 0 in queue_missed_stat_update in the stop return case
> 	if (!pcap || (pcap_stats(pcap, &stat) != 0))
> 	{
> 		missed_stat->pcap = 0;
> 		return missed_stat;
> 	}
> this way the missed_stat->pcap will always represent the current value from pcap and not hold old value
> specifically in case port is stopped it will be 0 and not re-added
> agree?
> 

This also works, but there is other condition in that if block, I don't know 
when 'pcap_stats()' can fail, it has a risk of unexpected side affect to clear 
the stats randomly, I think safer to do it in 
'queue_missed_stat_on_stop_update()' and I believe logic is more clear that way.

>>
>>> +}
>>> +
>>> +static void
>>> +queue_missed_stat_reset(struct rte_eth_dev *dev, unsigned int qid) {
>>> +	struct queue_missed_stat *missed_stat =
>>> +			queue_missed_stat_update(dev, qid);
>>> +	missed_stat->reset = missed_stat->pcap;
>>
>> I guess this should be:
>> "missed_stat->reset = missed_stat->pcap + missed_stat->mnemonic;"
> 
> I don't think so
> reset should only remember where pcap was at the reset point and not store old values
> trying it immediately results in
> 
> testpmd> show port stats 0
> 
>    ######################## NIC statistics for port 0  ########################
>    RX-packets: 0          RX-missed: 1940       RX-bytes:  0
>    RX-errors: 0
>    RX-nombuf:  0
>    TX-packets: 0          TX-errors: 0          TX-bytes:  0
> 
>    Throughput (since last show)
>    Rx-pps:            0          Rx-bps:            0
>    Tx-pps:            0          Tx-bps:            0
>    ############################################################################
> testpmd> clear port stats 0
> 
>    NIC statistics for port 0 cleared
> testpmd> show port stats 0
> 
>    ######################## NIC statistics for port 0  ########################
>    RX-packets: 0          RX-missed: 18446744073709550646 RX-bytes:  0
>    RX-errors: 0
>    RX-nombuf:  0
>    TX-packets: 0          TX-errors: 0          TX-bytes:  0
> 
>    Throughput (since last show)
>    Rx-pps:            0          Rx-bps:            0
>    Tx-pps:            0          Tx-bps:            0
>    ############################################################################
> 

What above shows, is it output after suggested change?



missed = "(pcap + mnemonic) - reset"
Lets assume overflow limit is 16, with original code:
reset: 0, pcap: 2, mnemonic: 16, missed: 18

clear stats:
reset: 2, pcap: 2, mnemonic: 16, missed: 16 (wrong, it should be 0)


OR
reset: 0, pcap: 2, mnemonic: 0, missed: 2

port stop:
reset: 0, pcap: 0, mnemonic: 2, missed: 2

port start, some traffic:
reset: 0, pcap: 3, mnemonic: 2, missed: 5

clear stats:
reset: 3, pcap: 3, mnemonic: 2, missed: 2 (wrong, it should be 0)


'mnemonic' becomes part of the stats after overflow or "port stop", so I think 
it should be stored in the reset.

As far as I can see suggested code change is required if I am not missing anything.


>>> +	missed_stat->mnemonic = 0;
>>> +}
>>> +
>>> +static unsigned long
>>> +queue_missed_stat_get(struct rte_eth_dev *dev, unsigned int qid) {
>>> +	const struct queue_missed_stat *missed_stat =
>>> +			queue_missed_stat_update(dev, qid);
>>> +	return missed_stat->pcap + missed_stat->mnemonic -
>>> +missed_stat->reset; }
>>> +
>>
>> <...>
  
Ido Goshen Feb. 4, 2021, 10:02 a.m. UTC | #4
> -----Original Message-----
> From: Ferruh Yigit <ferruh.yigit@intel.com>
> Sent: Thursday, 4 February 2021 11:26
> To: Ido Goshen <Ido@cgstowernetworks.com>
> Cc: dev@dpdk.org
> Subject: Re: [PATCH v3 1/1] net/pcap: imissed stats support
> 
> On 2/4/2021 7:56 AM, Ido Goshen wrote:
> >
> >
> >> -----Original Message-----
> >> From: Ferruh Yigit <ferruh.yigit@intel.com>
> >> Sent: Thursday, 4 February 2021 2:13
> >> To: Ido Goshen <Ido@cgstowernetworks.com>
> >> Cc: dev@dpdk.org
> >> Subject: Re: [PATCH v3 1/1] net/pcap: imissed stats support
> >>
> >> On 2/3/2021 11:07 PM, Ido Goshen wrote:
> >>> get value from pcap_stats.ps_drop (see man pcap_stats) the value is
> >>> adjusted in this cases:
> >>>    - port stop - pcap is closed and will lose count
> >>>    - stats reset - pcap doesn't provide reset api
> >>>    - rollover - pcap counter size is u_32 only
> >>>
> >>> Signed-off-by: Ido Goshen <ido@cgstowernetworks.com>
> >>> ---
> >>> v3:
> >>> * code cleanup by dedicated struct and functions extraction
> >>> * multi stop support by menmonic+= accumulation
> >>> * rollover fixup
> >>>
> >>> v2:
> >>> * sum all queues (rx_missed_total += fix)
> >>> * null pcap protection
> >>> * inter stop/start persistancy (counter won't reset on stop)
> >>>
> >>>    drivers/net/pcap/rte_eth_pcap.c | 59
> >> +++++++++++++++++++++++++++++++++
> >>>    1 file changed, 59 insertions(+)
> >>>
> >>> diff --git a/drivers/net/pcap/rte_eth_pcap.c
> >>> b/drivers/net/pcap/rte_eth_pcap.c index a32b1f3f3..16e8752f3 100644
> >>> --- a/drivers/net/pcap/rte_eth_pcap.c
> >>> +++ b/drivers/net/pcap/rte_eth_pcap.c
> >>> @@ -60,11 +60,21 @@ struct queue_stat {
> >>>    	volatile unsigned long err_pkts;
> >>>    };
> >>>
> >>> +struct queue_missed_stat {
> >>> +	/* last value retrieved from pcap */
> >>> +	volatile unsigned int pcap;
> >>> +	/* stores values lost by pcap stop or rollover */
> >>> +	volatile unsigned long mnemonic;
> >>> +	/* value on last reset */
> >>> +	volatile unsigned long reset;
> >>> +};
> >>
> >> I am aware other stats has 'volatile' keyword, but as far as I can
> >> see it is not needed, since these are new ones can you please drop the
> 'volatile'?
> >
> > ok
> >
> >>
> >>> +
> >>>    struct pcap_rx_queue {
> >>>    	uint16_t port_id;
> >>>    	uint16_t queue_id;
> >>>    	struct rte_mempool *mb_pool;
> >>>    	struct queue_stat rx_stat;
> >>> +	struct queue_missed_stat missed_stat;
> >>>    	char name[PATH_MAX];
> >>>    	char type[ETH_PCAP_ARG_MAXLEN];
> >>>
> >>> @@ -144,6 +154,49 @@ RTE_LOG_REGISTER(eth_pcap_logtype,
> >> pmd.net.pcap, NOTICE);
> >>>    	rte_log(RTE_LOG_ ## level, eth_pcap_logtype, \
> >>>    		"%s(): " fmt "\n", __func__, ##args)
> >>>
> >>> +static struct queue_missed_stat*
> >>> +queue_missed_stat_update(struct rte_eth_dev *dev, unsigned int qid) {
> >>> +	struct pmd_internals *internals = dev->data->dev_private;
> >>> +	struct queue_missed_stat *missed_stat =
> >>> +			&internals->rx_queue[qid].missed_stat;
> >>> +	const struct pmd_process_private *pp = dev->process_private;
> >>> +	pcap_t *pcap = pp->rx_pcap[qid];
> >>> +	struct pcap_stat stat;
> >>
> >> Can you please put an empty line after variable declarations, and before
> return.
> >
> > ok
> >
> >>
> >>> +	if (!pcap || (pcap_stats(pcap, &stat) != 0))
> >>> +		return missed_stat;
> >>> +	/* rollover check - best effort fixup assuming single rollover */
> >>> +	if (stat.ps_drop < missed_stat->pcap)
> >>> +		missed_stat->mnemonic += UINT_MAX;
> >>> +	missed_stat->pcap = stat.ps_drop;
> >>
> >> here.
> >>
> >>> +	return missed_stat;
> >>> +}
> >>> +
> >>> +static void
> >>> +queue_missed_stat_on_stop_update(struct rte_eth_dev *dev, unsigned
> >>> +int qid) {
> >>> +	struct queue_missed_stat *missed_stat =
> >>> +			queue_missed_stat_update(dev, qid);
> >>> +	missed_stat->mnemonic += missed_stat->pcap;
> >>
> >> Better to reset 'missed_stat->pcap' afterwards, in case stats
> >> requested before port started again:
> >>    missed_stat->pcap = 0;
> >
> > right, should be careful not to double count it but maybe better to
> > set it to 0 in queue_missed_stat_update in the stop return case
> > 	if (!pcap || (pcap_stats(pcap, &stat) != 0))
> > 	{
> > 		missed_stat->pcap = 0;
> > 		return missed_stat;
> > 	}
> > this way the missed_stat->pcap will always represent the current value
> > from pcap and not hold old value specifically in case port is stopped
> > it will be 0 and not re-added agree?
> >
> 
> This also works, but there is other condition in that if block, I don't know when
> 'pcap_stats()' can fail, it has a risk of unexpected side affect to clear the stats
> randomly, I think safer to do it in 'queue_missed_stat_on_stop_update()' and I
> believe logic is more clear that way.
> 

ok 

> >>
> >>> +}
> >>> +
> >>> +static void
> >>> +queue_missed_stat_reset(struct rte_eth_dev *dev, unsigned int qid) {
> >>> +	struct queue_missed_stat *missed_stat =
> >>> +			queue_missed_stat_update(dev, qid);
> >>> +	missed_stat->reset = missed_stat->pcap;
> >>
> >> I guess this should be:
> >> "missed_stat->reset = missed_stat->pcap + missed_stat->mnemonic;"
> >
> > I don't think so
> > reset should only remember where pcap was at the reset point and not store
> old values
> > trying it immediately results in
> >
> > testpmd> show port stats 0
> >
> >    ######################## NIC statistics for port 0
> ########################
> >    RX-packets: 0          RX-missed: 1940       RX-bytes:  0
> >    RX-errors: 0
> >    RX-nombuf:  0
> >    TX-packets: 0          TX-errors: 0          TX-bytes:  0
> >
> >    Throughput (since last show)
> >    Rx-pps:            0          Rx-bps:            0
> >    Tx-pps:            0          Tx-bps:            0
> >
> #################################################################
> ###########
> > testpmd> clear port stats 0
> >
> >    NIC statistics for port 0 cleared
> > testpmd> show port stats 0
> >
> >    ######################## NIC statistics for port 0
> ########################
> >    RX-packets: 0          RX-missed: 18446744073709550646 RX-bytes:  0
> >    RX-errors: 0
> >    RX-nombuf:  0
> >    TX-packets: 0          TX-errors: 0          TX-bytes:  0
> >
> >    Throughput (since last show)
> >    Rx-pps:            0          Rx-bps:            0
> >    Tx-pps:            0          Tx-bps:            0
> >
> #################################################################
> ###########
> >
> 
> What above shows, is it output after suggested change?
>

Yes it is **with** the suggested change (missed_stat->reset = missed_stat->pcap + missed_stat->mnemonic;)
Assume this sequence
port stop -> mnemonic = N, pcap = 0
reset stats -> reset = 0 + N, mnemonic = 0
show -> imissed = 0 + 0 - N


it works good w/o the suggested change (missed_stat->reset = missed_stat->pcap;)
testpmd> show port stats 0

  ######################## NIC statistics for port 0  ########################
  RX-packets: 0          RX-missed: 3932       RX-bytes:  0
  RX-errors: 0
  RX-nombuf:  0         
  TX-packets: 0          TX-errors: 0          TX-bytes:  0

  Throughput (since last show)
  Rx-pps:            0          Rx-bps:            0
  Tx-pps:            0          Tx-bps:            0
  ############################################################################
testpmd> clear port stats 0

  NIC statistics for port 0 cleared
testpmd> show port stats 0

  ######################## NIC statistics for port 0  ########################
  RX-packets: 0          RX-missed: 0          RX-bytes:  0
  RX-errors: 0
  RX-nombuf:  0         
  TX-packets: 0          TX-errors: 0          TX-bytes:  0

  Throughput (since last show)
  Rx-pps:            0          Rx-bps:            0
  Tx-pps:            0          Tx-bps:            0
  ############################################################################



 
> 
> 
> missed = "(pcap + mnemonic) - reset"
> Lets assume overflow limit is 16, with original code:
> reset: 0, pcap: 2, mnemonic: 16, missed: 18
> 
> clear stats:
> reset: 2, pcap: 2, mnemonic: 16, missed: 16 (wrong, it should be 0)
> 
> 
> OR
> reset: 0, pcap: 2, mnemonic: 0, missed: 2
> 
> port stop:
> reset: 0, pcap: 0, mnemonic: 2, missed: 2
> 
> port start, some traffic:
> reset: 0, pcap: 3, mnemonic: 2, missed: 5
> 
> clear stats:
> reset: 3, pcap: 3, mnemonic: 2, missed: 2 (wrong, it should be 0)
> 
> 
> 'mnemonic' becomes part of the stats after overflow or "port stop", so I think
> it should be stored in the reset.
> 
> As far as I can see suggested code change is required if I am not missing
> anything.
> 
> 
> >>> +	missed_stat->mnemonic = 0;
> >>> +}
> >>> +
> >>> +static unsigned long
> >>> +queue_missed_stat_get(struct rte_eth_dev *dev, unsigned int qid) {
> >>> +	const struct queue_missed_stat *missed_stat =
> >>> +			queue_missed_stat_update(dev, qid);
> >>> +	return missed_stat->pcap + missed_stat->mnemonic -
> >>> +missed_stat->reset; }
> >>> +
> >>
> >> <...>
  
Ferruh Yigit Feb. 4, 2021, 10:27 a.m. UTC | #5
On 2/4/2021 10:02 AM, Ido Goshen wrote:
> 
> 
>> -----Original Message-----
>> From: Ferruh Yigit <ferruh.yigit@intel.com>
>> Sent: Thursday, 4 February 2021 11:26
>> To: Ido Goshen <Ido@cgstowernetworks.com>
>> Cc: dev@dpdk.org
>> Subject: Re: [PATCH v3 1/1] net/pcap: imissed stats support
>>
>> On 2/4/2021 7:56 AM, Ido Goshen wrote:
>>>
>>>
>>>> -----Original Message-----
>>>> From: Ferruh Yigit <ferruh.yigit@intel.com>
>>>> Sent: Thursday, 4 February 2021 2:13
>>>> To: Ido Goshen <Ido@cgstowernetworks.com>
>>>> Cc: dev@dpdk.org
>>>> Subject: Re: [PATCH v3 1/1] net/pcap: imissed stats support
>>>>
>>>> On 2/3/2021 11:07 PM, Ido Goshen wrote:
>>>>> get value from pcap_stats.ps_drop (see man pcap_stats) the value is
>>>>> adjusted in this cases:
>>>>>     - port stop - pcap is closed and will lose count
>>>>>     - stats reset - pcap doesn't provide reset api
>>>>>     - rollover - pcap counter size is u_32 only
>>>>>
>>>>> Signed-off-by: Ido Goshen <ido@cgstowernetworks.com>
>>>>> ---
>>>>> v3:
>>>>> * code cleanup by dedicated struct and functions extraction
>>>>> * multi stop support by menmonic+= accumulation
>>>>> * rollover fixup
>>>>>
>>>>> v2:
>>>>> * sum all queues (rx_missed_total += fix)
>>>>> * null pcap protection
>>>>> * inter stop/start persistancy (counter won't reset on stop)
>>>>>
>>>>>     drivers/net/pcap/rte_eth_pcap.c | 59
>>>> +++++++++++++++++++++++++++++++++
>>>>>     1 file changed, 59 insertions(+)
>>>>>
>>>>> diff --git a/drivers/net/pcap/rte_eth_pcap.c
>>>>> b/drivers/net/pcap/rte_eth_pcap.c index a32b1f3f3..16e8752f3 100644
>>>>> --- a/drivers/net/pcap/rte_eth_pcap.c
>>>>> +++ b/drivers/net/pcap/rte_eth_pcap.c
>>>>> @@ -60,11 +60,21 @@ struct queue_stat {
>>>>>     	volatile unsigned long err_pkts;
>>>>>     };
>>>>>
>>>>> +struct queue_missed_stat {
>>>>> +	/* last value retrieved from pcap */
>>>>> +	volatile unsigned int pcap;
>>>>> +	/* stores values lost by pcap stop or rollover */
>>>>> +	volatile unsigned long mnemonic;
>>>>> +	/* value on last reset */
>>>>> +	volatile unsigned long reset;
>>>>> +};
>>>>
>>>> I am aware other stats has 'volatile' keyword, but as far as I can
>>>> see it is not needed, since these are new ones can you please drop the
>> 'volatile'?
>>>
>>> ok
>>>
>>>>
>>>>> +
>>>>>     struct pcap_rx_queue {
>>>>>     	uint16_t port_id;
>>>>>     	uint16_t queue_id;
>>>>>     	struct rte_mempool *mb_pool;
>>>>>     	struct queue_stat rx_stat;
>>>>> +	struct queue_missed_stat missed_stat;
>>>>>     	char name[PATH_MAX];
>>>>>     	char type[ETH_PCAP_ARG_MAXLEN];
>>>>>
>>>>> @@ -144,6 +154,49 @@ RTE_LOG_REGISTER(eth_pcap_logtype,
>>>> pmd.net.pcap, NOTICE);
>>>>>     	rte_log(RTE_LOG_ ## level, eth_pcap_logtype, \
>>>>>     		"%s(): " fmt "\n", __func__, ##args)
>>>>>
>>>>> +static struct queue_missed_stat*
>>>>> +queue_missed_stat_update(struct rte_eth_dev *dev, unsigned int qid) {
>>>>> +	struct pmd_internals *internals = dev->data->dev_private;
>>>>> +	struct queue_missed_stat *missed_stat =
>>>>> +			&internals->rx_queue[qid].missed_stat;
>>>>> +	const struct pmd_process_private *pp = dev->process_private;
>>>>> +	pcap_t *pcap = pp->rx_pcap[qid];
>>>>> +	struct pcap_stat stat;
>>>>
>>>> Can you please put an empty line after variable declarations, and before
>> return.
>>>
>>> ok
>>>
>>>>
>>>>> +	if (!pcap || (pcap_stats(pcap, &stat) != 0))
>>>>> +		return missed_stat;
>>>>> +	/* rollover check - best effort fixup assuming single rollover */
>>>>> +	if (stat.ps_drop < missed_stat->pcap)
>>>>> +		missed_stat->mnemonic += UINT_MAX;
>>>>> +	missed_stat->pcap = stat.ps_drop;
>>>>
>>>> here.
>>>>
>>>>> +	return missed_stat;
>>>>> +}
>>>>> +
>>>>> +static void
>>>>> +queue_missed_stat_on_stop_update(struct rte_eth_dev *dev, unsigned
>>>>> +int qid) {
>>>>> +	struct queue_missed_stat *missed_stat =
>>>>> +			queue_missed_stat_update(dev, qid);
>>>>> +	missed_stat->mnemonic += missed_stat->pcap;
>>>>
>>>> Better to reset 'missed_stat->pcap' afterwards, in case stats
>>>> requested before port started again:
>>>>     missed_stat->pcap = 0;
>>>
>>> right, should be careful not to double count it but maybe better to
>>> set it to 0 in queue_missed_stat_update in the stop return case
>>> 	if (!pcap || (pcap_stats(pcap, &stat) != 0))
>>> 	{
>>> 		missed_stat->pcap = 0;
>>> 		return missed_stat;
>>> 	}
>>> this way the missed_stat->pcap will always represent the current value
>>> from pcap and not hold old value specifically in case port is stopped
>>> it will be 0 and not re-added agree?
>>>
>>
>> This also works, but there is other condition in that if block, I don't know when
>> 'pcap_stats()' can fail, it has a risk of unexpected side affect to clear the stats
>> randomly, I think safer to do it in 'queue_missed_stat_on_stop_update()' and I
>> believe logic is more clear that way.
>>
> 
> ok
> 
>>>>
>>>>> +}
>>>>> +
>>>>> +static void
>>>>> +queue_missed_stat_reset(struct rte_eth_dev *dev, unsigned int qid) {
>>>>> +	struct queue_missed_stat *missed_stat =
>>>>> +			queue_missed_stat_update(dev, qid);
>>>>> +	missed_stat->reset = missed_stat->pcap;
>>>>
>>>> I guess this should be:
>>>> "missed_stat->reset = missed_stat->pcap + missed_stat->mnemonic;"
>>>
>>> I don't think so
>>> reset should only remember where pcap was at the reset point and not store
>> old values
>>> trying it immediately results in
>>>
>>> testpmd> show port stats 0
>>>
>>>     ######################## NIC statistics for port 0
>> ########################
>>>     RX-packets: 0          RX-missed: 1940       RX-bytes:  0
>>>     RX-errors: 0
>>>     RX-nombuf:  0
>>>     TX-packets: 0          TX-errors: 0          TX-bytes:  0
>>>
>>>     Throughput (since last show)
>>>     Rx-pps:            0          Rx-bps:            0
>>>     Tx-pps:            0          Tx-bps:            0
>>>
>> #################################################################
>> ###########
>>> testpmd> clear port stats 0
>>>
>>>     NIC statistics for port 0 cleared
>>> testpmd> show port stats 0
>>>
>>>     ######################## NIC statistics for port 0
>> ########################
>>>     RX-packets: 0          RX-missed: 18446744073709550646 RX-bytes:  0
>>>     RX-errors: 0
>>>     RX-nombuf:  0
>>>     TX-packets: 0          TX-errors: 0          TX-bytes:  0
>>>
>>>     Throughput (since last show)
>>>     Rx-pps:            0          Rx-bps:            0
>>>     Tx-pps:            0          Tx-bps:            0
>>>
>> #################################################################
>> ###########
>>>
>>
>> What above shows, is it output after suggested change?
>>
> 
> Yes it is **with** the suggested change (missed_stat->reset = missed_stat->pcap + missed_stat->mnemonic;)
> Assume this sequence
> port stop -> mnemonic = N, pcap = 0
> reset stats -> reset = 0 + N, mnemonic = 0
> show -> imissed = 0 + 0 - N
> 
> 
> it works good w/o the suggested change (missed_stat->reset = missed_stat->pcap;)
> testpmd> show port stats 0
> 
>    ######################## NIC statistics for port 0  ########################
>    RX-packets: 0          RX-missed: 3932       RX-bytes:  0
>    RX-errors: 0
>    RX-nombuf:  0
>    TX-packets: 0          TX-errors: 0          TX-bytes:  0
> 
>    Throughput (since last show)
>    Rx-pps:            0          Rx-bps:            0
>    Tx-pps:            0          Tx-bps:            0
>    ############################################################################
> testpmd> clear port stats 0
> 
>    NIC statistics for port 0 cleared
> testpmd> show port stats 0
> 
>    ######################## NIC statistics for port 0  ########################
>    RX-packets: 0          RX-missed: 0          RX-bytes:  0
>    RX-errors: 0
>    RX-nombuf:  0
>    TX-packets: 0          TX-errors: 0          TX-bytes:  0
> 
>    Throughput (since last show)
>    Rx-pps:            0          Rx-bps:            0
>    Tx-pps:            0          Tx-bps:            0
>    ############################################################################
> 
> 

I missed 'mnemonic' get zeroed out in the "clear stats", existing implementation 
looks good, thanks for clarification.

> 
>   
>>
>>
>> missed = "(pcap + mnemonic) - reset"
>> Lets assume overflow limit is 16, with original code:
>> reset: 0, pcap: 2, mnemonic: 16, missed: 18
>>
>> clear stats:
>> reset: 2, pcap: 2, mnemonic: 16, missed: 16 (wrong, it should be 0)
>>
>>
>> OR
>> reset: 0, pcap: 2, mnemonic: 0, missed: 2
>>
>> port stop:
>> reset: 0, pcap: 0, mnemonic: 2, missed: 2
>>
>> port start, some traffic:
>> reset: 0, pcap: 3, mnemonic: 2, missed: 5
>>
>> clear stats:
>> reset: 3, pcap: 3, mnemonic: 2, missed: 2 (wrong, it should be 0)
>>
>>
>> 'mnemonic' becomes part of the stats after overflow or "port stop", so I think
>> it should be stored in the reset.
>>
>> As far as I can see suggested code change is required if I am not missing
>> anything.
>>
>>
>>>>> +	missed_stat->mnemonic = 0;
>>>>> +}
>>>>> +
>>>>> +static unsigned long
>>>>> +queue_missed_stat_get(struct rte_eth_dev *dev, unsigned int qid) {
>>>>> +	const struct queue_missed_stat *missed_stat =
>>>>> +			queue_missed_stat_update(dev, qid);
>>>>> +	return missed_stat->pcap + missed_stat->mnemonic -
>>>>> +missed_stat->reset; }
>>>>> +
>>>>
>>>> <...>
>
  

Patch

diff --git a/drivers/net/pcap/rte_eth_pcap.c b/drivers/net/pcap/rte_eth_pcap.c
index a32b1f3f3..16e8752f3 100644
--- a/drivers/net/pcap/rte_eth_pcap.c
+++ b/drivers/net/pcap/rte_eth_pcap.c
@@ -60,11 +60,21 @@  struct queue_stat {
 	volatile unsigned long err_pkts;
 };
 
+struct queue_missed_stat {
+	/* last value retrieved from pcap */
+	volatile unsigned int pcap;
+	/* stores values lost by pcap stop or rollover */
+	volatile unsigned long mnemonic;
+	/* value on last reset */
+	volatile unsigned long reset;
+};
+
 struct pcap_rx_queue {
 	uint16_t port_id;
 	uint16_t queue_id;
 	struct rte_mempool *mb_pool;
 	struct queue_stat rx_stat;
+	struct queue_missed_stat missed_stat;
 	char name[PATH_MAX];
 	char type[ETH_PCAP_ARG_MAXLEN];
 
@@ -144,6 +154,49 @@  RTE_LOG_REGISTER(eth_pcap_logtype, pmd.net.pcap, NOTICE);
 	rte_log(RTE_LOG_ ## level, eth_pcap_logtype, \
 		"%s(): " fmt "\n", __func__, ##args)
 
+static struct queue_missed_stat*
+queue_missed_stat_update(struct rte_eth_dev *dev, unsigned int qid)
+{
+	struct pmd_internals *internals = dev->data->dev_private;
+	struct queue_missed_stat *missed_stat =
+			&internals->rx_queue[qid].missed_stat;
+	const struct pmd_process_private *pp = dev->process_private;
+	pcap_t *pcap = pp->rx_pcap[qid];
+	struct pcap_stat stat;
+	if (!pcap || (pcap_stats(pcap, &stat) != 0))
+		return missed_stat;
+	/* rollover check - best effort fixup assuming single rollover */
+	if (stat.ps_drop < missed_stat->pcap)
+		missed_stat->mnemonic += UINT_MAX;
+	missed_stat->pcap = stat.ps_drop;
+	return missed_stat;
+}
+
+static void
+queue_missed_stat_on_stop_update(struct rte_eth_dev *dev, unsigned int qid)
+{
+	struct queue_missed_stat *missed_stat =
+			queue_missed_stat_update(dev, qid);
+	missed_stat->mnemonic += missed_stat->pcap;
+}
+
+static void
+queue_missed_stat_reset(struct rte_eth_dev *dev, unsigned int qid)
+{
+	struct queue_missed_stat *missed_stat =
+			queue_missed_stat_update(dev, qid);
+	missed_stat->reset = missed_stat->pcap;
+	missed_stat->mnemonic = 0;
+}
+
+static unsigned long
+queue_missed_stat_get(struct rte_eth_dev *dev, unsigned int qid)
+{
+	const struct queue_missed_stat *missed_stat =
+			queue_missed_stat_update(dev, qid);
+	return missed_stat->pcap + missed_stat->mnemonic - missed_stat->reset;
+}
+
 static int
 eth_pcap_rx_jumbo(struct rte_mempool *mb_pool, struct rte_mbuf *mbuf,
 		const u_char *data, uint16_t data_len)
@@ -621,6 +674,7 @@  eth_dev_stop(struct rte_eth_dev *dev)
 
 	/* Special iface case. Single pcap is open and shared between tx/rx. */
 	if (internals->single_iface) {
+		queue_missed_stat_on_stop_update(dev, 0);
 		pcap_close(pp->tx_pcap[0]);
 		pp->tx_pcap[0] = NULL;
 		pp->rx_pcap[0] = NULL;
@@ -641,6 +695,7 @@  eth_dev_stop(struct rte_eth_dev *dev)
 
 	for (i = 0; i < dev->data->nb_rx_queues; i++) {
 		if (pp->rx_pcap[i] != NULL) {
+			queue_missed_stat_on_stop_update(dev, i);
 			pcap_close(pp->rx_pcap[i]);
 			pp->rx_pcap[i] = NULL;
 		}
@@ -685,6 +740,7 @@  eth_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *stats)
 {
 	unsigned int i;
 	unsigned long rx_packets_total = 0, rx_bytes_total = 0;
+	unsigned long rx_missed_total = 0;
 	unsigned long tx_packets_total = 0, tx_bytes_total = 0;
 	unsigned long tx_packets_err_total = 0;
 	const struct pmd_internals *internal = dev->data->dev_private;
@@ -695,6 +751,7 @@  eth_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *stats)
 		stats->q_ibytes[i] = internal->rx_queue[i].rx_stat.bytes;
 		rx_packets_total += stats->q_ipackets[i];
 		rx_bytes_total += stats->q_ibytes[i];
+		rx_missed_total += queue_missed_stat_get(dev, i);
 	}
 
 	for (i = 0; i < RTE_ETHDEV_QUEUE_STAT_CNTRS &&
@@ -708,6 +765,7 @@  eth_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *stats)
 
 	stats->ipackets = rx_packets_total;
 	stats->ibytes = rx_bytes_total;
+	stats->imissed = rx_missed_total;
 	stats->opackets = tx_packets_total;
 	stats->obytes = tx_bytes_total;
 	stats->oerrors = tx_packets_err_total;
@@ -724,6 +782,7 @@  eth_stats_reset(struct rte_eth_dev *dev)
 	for (i = 0; i < dev->data->nb_rx_queues; i++) {
 		internal->rx_queue[i].rx_stat.pkts = 0;
 		internal->rx_queue[i].rx_stat.bytes = 0;
+		queue_missed_stat_reset(dev, i);
 	}
 
 	for (i = 0; i < dev->data->nb_tx_queues; i++) {