[v5,6/7] power: support monitoring multiple Rx queues

  Use the new multi-monitor intrinsic to allow monitoring multiple ethdev
Rx queues while entering the energy efficient power state. The multi
version will be used unconditionally if supported, and the UMWAIT one
will only be used when multi-monitor is not supported by the hardware.

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
---

Notes:
    v4:
    - Fix possible out of bounds access
    - Added missing index increment

 doc/guides/prog_guide/power_man.rst |  9 ++--
 lib/power/rte_power_pmd_mgmt.c      | 81 ++++++++++++++++++++++++++++-
 2 files changed, 85 insertions(+), 5 deletions(-)
  

> Use the new multi-monitor intrinsic to allow monitoring multiple ethdev
> Rx queues while entering the energy efficient power state. The multi
> version will be used unconditionally if supported, and the UMWAIT one
> will only be used when multi-monitor is not supported by the hardware.
> 
> Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
> ---
> 
> Notes:
>     v4:
>     - Fix possible out of bounds access
>     - Added missing index increment
> 
>  doc/guides/prog_guide/power_man.rst |  9 ++--
>  lib/power/rte_power_pmd_mgmt.c      | 81 ++++++++++++++++++++++++++++-
>  2 files changed, 85 insertions(+), 5 deletions(-)
> 
> diff --git a/doc/guides/prog_guide/power_man.rst b/doc/guides/prog_guide/power_man.rst
> index ec04a72108..94353ca012 100644
> --- a/doc/guides/prog_guide/power_man.rst
> +++ b/doc/guides/prog_guide/power_man.rst
> @@ -221,13 +221,16 @@ power saving whenever empty poll count reaches a certain number.
>  The "monitor" mode is only supported in the following configurations and scenarios:
> 
>  * If ``rte_cpu_get_intrinsics_support()`` function indicates that
> +  ``rte_power_monitor_multi()`` function is supported by the platform, then
> +  monitoring multiple Ethernet Rx queues for traffic will be supported.
> +
> +* If ``rte_cpu_get_intrinsics_support()`` function indicates that only
>    ``rte_power_monitor()`` is supported by the platform, then monitoring will be
>    limited to a mapping of 1 core 1 queue (thus, each Rx queue will have to be
>    monitored from a different lcore).
> 
> -* If ``rte_cpu_get_intrinsics_support()`` function indicates that the
> -  ``rte_power_monitor()`` function is not supported, then monitor mode will not
> -  be supported.
> +* If ``rte_cpu_get_intrinsics_support()`` function indicates that neither of the
> +  two monitoring functions are supported, then monitor mode will not be supported.
> 
>  * Not all Ethernet drivers support monitoring, even if the underlying
>    platform may support the necessary CPU instructions. Please refer to
> diff --git a/lib/power/rte_power_pmd_mgmt.c b/lib/power/rte_power_pmd_mgmt.c
> index fccfd236c2..2056996b9c 100644
> --- a/lib/power/rte_power_pmd_mgmt.c
> +++ b/lib/power/rte_power_pmd_mgmt.c
> @@ -124,6 +124,32 @@ queue_list_take(struct pmd_core_cfg *cfg, const union queue *q)
>  	return found;
>  }
> 
> +static inline int
> +get_monitor_addresses(struct pmd_core_cfg *cfg,
> +		struct rte_power_monitor_cond *pmc, size_t len)
> +{
> +	const struct queue_list_entry *qle;
> +	size_t i = 0;
> +	int ret;
> +
> +	TAILQ_FOREACH(qle, &cfg->head, next) {
> +		const union queue *q = &qle->queue;
> +		struct rte_power_monitor_cond *cur;
> +
> +		/* attempted out of bounds access */
> +		if (i >= len) {
> +			RTE_LOG(ERR, POWER, "Too many queues being monitored\n");
> +			return -1;
> +		}
> +
> +		cur = &pmc[i++];
> +		ret = rte_eth_get_monitor_addr(q->portid, q->qid, cur);
> +		if (ret < 0)
> +			return ret;
> +	}
> +	return 0;
> +}
> +
>  static void
>  calc_tsc(void)
>  {
> @@ -190,6 +216,45 @@ lcore_can_sleep(struct pmd_core_cfg *cfg)
>  	return true;
>  }
> 
> +static uint16_t
> +clb_multiwait(uint16_t port_id __rte_unused, uint16_t qidx __rte_unused,
> +		struct rte_mbuf **pkts __rte_unused, uint16_t nb_rx,
> +		uint16_t max_pkts __rte_unused, void *arg)
> +{
> +	const unsigned int lcore = rte_lcore_id();
> +	struct queue_list_entry *queue_conf = arg;
> +	struct pmd_core_cfg *lcore_conf;
> +	const bool empty = nb_rx == 0;
> +
> +	lcore_conf = &lcore_cfgs[lcore];
> +
> +	/* early exit */
> +	if (likely(!empty))
> +		/* early exit */
> +		queue_reset(lcore_conf, queue_conf);
> +	else {
> +		struct rte_power_monitor_cond pmc[RTE_MAX_ETHPORTS];

As discussed, I still think it needs to be pmc[lcore_conf->n_queues];
Or if VLA is not an option - alloca(), or dynamic lcore_conf->pmc[], or...

> +		int ret;
> +
> +		/* can this queue sleep? */
> +		if (!queue_can_sleep(lcore_conf, queue_conf))
> +			return nb_rx;
> +
> +		/* can this lcore sleep? */
> +		if (!lcore_can_sleep(lcore_conf))
> +			return nb_rx;
> +
> +		/* gather all monitoring conditions */
> +		ret = get_monitor_addresses(lcore_conf, pmc, RTE_DIM(pmc));
> +		if (ret < 0)
> +			return nb_rx;
> +
> +		rte_power_monitor_multi(pmc, lcore_conf->n_queues, UINT64_MAX);
> +	}
> +
> +	return nb_rx;
> +}
> +
>  static uint16_t
>  clb_umwait(uint16_t port_id, uint16_t qidx, struct rte_mbuf **pkts __rte_unused,
>  		uint16_t nb_rx, uint16_t max_pkts __rte_unused, void *arg)
> @@ -341,14 +406,19 @@ static int
>  check_monitor(struct pmd_core_cfg *cfg, const union queue *qdata)
>  {
>  	struct rte_power_monitor_cond dummy;
> +	bool multimonitor_supported;
> 
>  	/* check if rte_power_monitor is supported */
>  	if (!global_data.intrinsics_support.power_monitor) {
>  		RTE_LOG(DEBUG, POWER, "Monitoring intrinsics are not supported\n");
>  		return -ENOTSUP;
>  	}
> +	/* check if multi-monitor is supported */
> +	multimonitor_supported =
> +			global_data.intrinsics_support.power_monitor_multi;
> 
> -	if (cfg->n_queues > 0) {
> +	/* if we're adding a new queue, do we support multiple queues? */
> +	if (cfg->n_queues > 0 && !multimonitor_supported) {
>  		RTE_LOG(DEBUG, POWER, "Monitoring multiple queues is not supported\n");
>  		return -ENOTSUP;
>  	}
> @@ -364,6 +434,13 @@ check_monitor(struct pmd_core_cfg *cfg, const union queue *qdata)
>  	return 0;
>  }
> 
> +static inline rte_rx_callback_fn
> +get_monitor_callback(void)
> +{
> +	return global_data.intrinsics_support.power_monitor_multi ?
> +		clb_multiwait : clb_umwait;
> +}
> +
>  int
>  rte_power_ethdev_pmgmt_queue_enable(unsigned int lcore_id, uint16_t port_id,
>  		uint16_t queue_id, enum rte_power_pmd_mgmt_type mode)
> @@ -428,7 +505,7 @@ rte_power_ethdev_pmgmt_queue_enable(unsigned int lcore_id, uint16_t port_id,
>  		if (ret < 0)
>  			goto end;
> 
> -		clb = clb_umwait;
> +		clb = get_monitor_callback();
>  		break;
>  	case RTE_POWER_MGMT_TYPE_SCALE:
>  		/* check if we can add a new queue */
> --
> 2.25.1
  

On 30-Jun-21 11:29 AM, Ananyev, Konstantin wrote:
> 
> 
>> Use the new multi-monitor intrinsic to allow monitoring multiple ethdev
>> Rx queues while entering the energy efficient power state. The multi
>> version will be used unconditionally if supported, and the UMWAIT one
>> will only be used when multi-monitor is not supported by the hardware.
>>
>> Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
>> ---
>>
>> Notes:
>>      v4:
>>      - Fix possible out of bounds access
>>      - Added missing index increment
>>
>>   doc/guides/prog_guide/power_man.rst |  9 ++--
>>   lib/power/rte_power_pmd_mgmt.c      | 81 ++++++++++++++++++++++++++++-
>>   2 files changed, 85 insertions(+), 5 deletions(-)
>>
>> diff --git a/doc/guides/prog_guide/power_man.rst b/doc/guides/prog_guide/power_man.rst
>> index ec04a72108..94353ca012 100644
>> --- a/doc/guides/prog_guide/power_man.rst
>> +++ b/doc/guides/prog_guide/power_man.rst
>> @@ -221,13 +221,16 @@ power saving whenever empty poll count reaches a certain number.
>>   The "monitor" mode is only supported in the following configurations and scenarios:
>>
>>   * If ``rte_cpu_get_intrinsics_support()`` function indicates that
>> +  ``rte_power_monitor_multi()`` function is supported by the platform, then
>> +  monitoring multiple Ethernet Rx queues for traffic will be supported.
>> +
>> +* If ``rte_cpu_get_intrinsics_support()`` function indicates that only
>>     ``rte_power_monitor()`` is supported by the platform, then monitoring will be
>>     limited to a mapping of 1 core 1 queue (thus, each Rx queue will have to be
>>     monitored from a different lcore).
>>
>> -* If ``rte_cpu_get_intrinsics_support()`` function indicates that the
>> -  ``rte_power_monitor()`` function is not supported, then monitor mode will not
>> -  be supported.
>> +* If ``rte_cpu_get_intrinsics_support()`` function indicates that neither of the
>> +  two monitoring functions are supported, then monitor mode will not be supported.
>>
>>   * Not all Ethernet drivers support monitoring, even if the underlying
>>     platform may support the necessary CPU instructions. Please refer to
>> diff --git a/lib/power/rte_power_pmd_mgmt.c b/lib/power/rte_power_pmd_mgmt.c
>> index fccfd236c2..2056996b9c 100644
>> --- a/lib/power/rte_power_pmd_mgmt.c
>> +++ b/lib/power/rte_power_pmd_mgmt.c
>> @@ -124,6 +124,32 @@ queue_list_take(struct pmd_core_cfg *cfg, const union queue *q)
>>        return found;
>>   }
>>
>> +static inline int
>> +get_monitor_addresses(struct pmd_core_cfg *cfg,
>> +             struct rte_power_monitor_cond *pmc, size_t len)
>> +{
>> +     const struct queue_list_entry *qle;
>> +     size_t i = 0;
>> +     int ret;
>> +
>> +     TAILQ_FOREACH(qle, &cfg->head, next) {
>> +             const union queue *q = &qle->queue;
>> +             struct rte_power_monitor_cond *cur;
>> +
>> +             /* attempted out of bounds access */
>> +             if (i >= len) {
>> +                     RTE_LOG(ERR, POWER, "Too many queues being monitored\n");
>> +                     return -1;
>> +             }
>> +
>> +             cur = &pmc[i++];
>> +             ret = rte_eth_get_monitor_addr(q->portid, q->qid, cur);
>> +             if (ret < 0)
>> +                     return ret;
>> +     }
>> +     return 0;
>> +}
>> +
>>   static void
>>   calc_tsc(void)
>>   {
>> @@ -190,6 +216,45 @@ lcore_can_sleep(struct pmd_core_cfg *cfg)
>>        return true;
>>   }
>>
>> +static uint16_t
>> +clb_multiwait(uint16_t port_id __rte_unused, uint16_t qidx __rte_unused,
>> +             struct rte_mbuf **pkts __rte_unused, uint16_t nb_rx,
>> +             uint16_t max_pkts __rte_unused, void *arg)
>> +{
>> +     const unsigned int lcore = rte_lcore_id();
>> +     struct queue_list_entry *queue_conf = arg;
>> +     struct pmd_core_cfg *lcore_conf;
>> +     const bool empty = nb_rx == 0;
>> +
>> +     lcore_conf = &lcore_cfgs[lcore];
>> +
>> +     /* early exit */
>> +     if (likely(!empty))
>> +             /* early exit */
>> +             queue_reset(lcore_conf, queue_conf);
>> +     else {
>> +             struct rte_power_monitor_cond pmc[RTE_MAX_ETHPORTS];
> 
> As discussed, I still think it needs to be pmc[lcore_conf->n_queues];
> Or if VLA is not an option - alloca(), or dynamic lcore_conf->pmc[], or...
> 

Apologies, this was a rebase mistake. Thanks for catching it! Will fix 
in v6.