[dpdk-dev] [PATCH 5/5] rte_sched: allow reading without clearing

[Dumitrescu, Cristian]

> -----Original Message-----
> From: Stephen Hemminger [mailto:stephen at networkplumber.org]
> Sent: Wednesday, May 27, 2015 7:10 PM
> To: Dumitrescu, Cristian
> Cc: dev at dpdk.org; Stephen Hemminger
> Subject: [PATCH 5/5] rte_sched: allow reading without clearing
> 
> The rte_sched statistics API should allow reading statistics without
> clearing. Make auto-clear optional. In this version, this is handled
> by deprecating the old API and adding a new one.
> 
> Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
> ---
>  app/test/test_sched.c                  |  4 +--
>  lib/librte_sched/rte_sched.c           | 65 +++++++++++++++++++++-------------
>  lib/librte_sched/rte_sched.h           | 37 ++++++++++++++-----
>  lib/librte_sched/rte_sched_version.map |  2 ++
>  4 files changed, 74 insertions(+), 34 deletions(-)
> 
> diff --git a/app/test/test_sched.c b/app/test/test_sched.c
> index c7239f8..03f89b4 100644
> --- a/app/test/test_sched.c
> +++ b/app/test/test_sched.c
> @@ -198,13 +198,13 @@ test_sched(void)
> 
>  	struct rte_sched_subport_stats subport_stats;
>  	uint32_t tc_ov;
> -	rte_sched_subport_read_stats(port, SUBPORT, &subport_stats,
> &tc_ov);
> +	rte_sched_subport_stats(port, SUBPORT, &subport_stats, &tc_ov,
> 1);
>  #if 0
>  	TEST_ASSERT_EQUAL(subport_stats.n_pkts_tc[TC-1], 10, "Wrong
> subport stats\n");
>  #endif
>  	struct rte_sched_queue_stats queue_stats;
>  	uint16_t qlen;
> -	rte_sched_queue_read_stats(port, QUEUE, &queue_stats, &qlen);
> +	rte_sched_queue_stats(port, QUEUE, &queue_stats, &qlen, 1);
>  #if 0
>  	TEST_ASSERT_EQUAL(queue_stats.n_pkts, 10, "Wrong queue
> stats\n");
>  #endif
> diff --git a/lib/librte_sched/rte_sched.c b/lib/librte_sched/rte_sched.c
> index 9c9419d..b4d7edd 100644
> --- a/lib/librte_sched/rte_sched.c
> +++ b/lib/librte_sched/rte_sched.c
> @@ -965,61 +965,78 @@ rte_sched_port_pkt_read_color(const struct
> rte_mbuf *pkt)
>  }
> 
>  int
> -rte_sched_subport_read_stats(struct rte_sched_port *port,
> -	uint32_t subport_id,
> -	struct rte_sched_subport_stats *stats,
> -	uint32_t *tc_ov)
> +rte_sched_subport_stats(struct rte_sched_port *port, uint32_t
> subport_id,
> +			struct rte_sched_subport_stats *stats,
> +			uint32_t *tc_ov, int clear)
>  {
>  	struct rte_sched_subport *s;
> 
>  	/* Check user parameters */
> -	if ((port == NULL) ||
> -	    (subport_id >= port->n_subports_per_port) ||
> -		(stats == NULL) ||
> -		(tc_ov == NULL)) {
> +	if (port == NULL || subport_id >= port->n_subports_per_port)
>  		return -1;
> -	}
> +
>  	s = port->subport + subport_id;
> 
>  	/* Copy subport stats and clear */
> -	memcpy(stats, &s->stats, sizeof(struct rte_sched_subport_stats));
> -	memset(&s->stats, 0, sizeof(struct rte_sched_subport_stats));
> +	if (stats)
> +		*stats = s->stats;
> +	if (clear)
> +		memset(&s->stats, 0, sizeof(struct
> rte_sched_subport_stats));
> 
>  	/* Subport TC ovesubscription status */
> -	*tc_ov = s->tc_ov;
> +	if (tc_ov)
> +		*tc_ov = s->tc_ov;
> 
>  	return 0;
>  }
> 
> +/* Deprecated API, always clears */
>  int
> -rte_sched_queue_read_stats(struct rte_sched_port *port,
> -	uint32_t queue_id,
> -	struct rte_sched_queue_stats *stats,
> -	uint16_t *qlen)
> +rte_sched_subport_read_stats(struct rte_sched_port *port, uint32_t
> subport_id,
> +			     struct rte_sched_subport_stats *stats,
> +			     uint32_t *tc_ov)
> +{
> +	return rte_sched_subport_stats(port, subport_id, stats, tc_ov, 1);
> +}
> +
> +int
> +rte_sched_queue_stats(struct rte_sched_port *port, uint32_t queue_id,
> +		      struct rte_sched_queue_stats *stats,
> +		      uint16_t *qlen, int clear)
>  {
>  	struct rte_sched_queue *q;
>  	struct rte_sched_queue_extra *qe;
> 
>  	/* Check user parameters */
> -	if ((port == NULL) ||
> -	    (queue_id >= rte_sched_port_queues_per_port(port)) ||
> -		(stats == NULL) ||
> -		(qlen == NULL)) {
> +	if (port == NULL || queue_id >=
> rte_sched_port_queues_per_port(port))
>  		return -1;
> -	}
> +
>  	q = port->queue + queue_id;
>  	qe = port->queue_extra + queue_id;
> 
>  	/* Copy queue stats and clear */
> -	memcpy(stats, &qe->stats, sizeof(struct rte_sched_queue_stats));
> -	memset(&qe->stats, 0, sizeof(struct rte_sched_queue_stats));
> +	if (stats)
> +		*stats = qe->stats;
> +	if (clear)
> +		memset(&qe->stats, 0, sizeof(struct
> rte_sched_queue_stats));
> 
>  	/* Queue length */
> -	*qlen = q->qw - q->qr;
> +	if (qlen)
> +		*qlen = q->qw - q->qr;
> 
>  	return 0;
>  }
> 
> +/* Deprecated API, always clears */
> +int
> +rte_sched_queue_read_stats(struct rte_sched_port *port,
> +	uint32_t queue_id,
> +	struct rte_sched_queue_stats *stats,
> +	uint16_t *qlen)
> +{
> +	return rte_sched_queue_stats(port, queue_id, stats, qlen, 1);
> +}
> +
>  static inline uint32_t
>  rte_sched_port_qindex(struct rte_sched_port *port, uint32_t subport,
> uint32_t pipe, uint32_t traffic_class, uint32_t queue)
>  {
> diff --git a/lib/librte_sched/rte_sched.h b/lib/librte_sched/rte_sched.h
> index f7c0b8e..053454c 100644
> --- a/lib/librte_sched/rte_sched.h
> +++ b/lib/librte_sched/rte_sched.h
> @@ -300,14 +300,24 @@ rte_sched_port_get_memory_footprint(struct
> rte_sched_port_params *params);
>   * @param tc_ov
>   *   Pointer to pre-allocated 4-entry array where the oversubscription status
> for
>   *   each of the 4 subport traffic classes should be stored.
> + * @parm clear
> + *   Reset statistics after read
> + *
>   * @return
>   *   0 upon success, error code otherwise
>   */
>  int
> -rte_sched_subport_read_stats(struct rte_sched_port *port,
> -	uint32_t subport_id,
> -	struct rte_sched_subport_stats *stats,
> -	uint32_t *tc_ov);
> +rte_sched_subport_stats(struct rte_sched_port *port, uint32_t
> subport_id,
> +			struct rte_sched_subport_stats *stats,
> +			uint32_t *tc_ov, int clear);
> +
> +/* Note: use rte_sched_subport_stats() instead,
> + * which allows separate read and clear.
> + */
> +int
> +rte_sched_subport_read_stats(struct rte_sched_port *port, uint32_t
> subport_id,
> +			     struct rte_sched_subport_stats *stats,
> +			     uint32_t *tc_ov) __attribute__((deprecated));
> 
>  /**
>   * Hierarchical scheduler queue statistics read
> @@ -321,14 +331,25 @@ rte_sched_subport_read_stats(struct
> rte_sched_port *port,
>   *   counters should be stored
>   * @param qlen
>   *   Pointer to pre-allocated variable where the current queue length should
> be stored.
> + * @parm clear
> + *   Reset statistics after read
>   * @return
>   *   0 upon success, error code otherwise
>   */
>  int
> -rte_sched_queue_read_stats(struct rte_sched_port *port,
> -	uint32_t queue_id,
> -	struct rte_sched_queue_stats *stats,
> -	uint16_t *qlen);
> +rte_sched_queue_stats(struct rte_sched_port *port,
> +		      uint32_t queue_id,
> +		      struct rte_sched_queue_stats *stats,
> +		      uint16_t *qlen, int clear);
> +
> +
> +/* Note: use rte_sched_queue_stats() instead
> + * which allows separate read and clear.
> + */
> +int
> +rte_sched_queue_read_stats(struct rte_sched_port *port, uint32_t
> queue_id,
> +			   struct rte_sched_queue_stats *stats,
> +			   uint16_t *qlen) __attribute__((deprecated));
> 
>  /**
>   * Scheduler hierarchy path write to packet descriptor. Typically called by the
> diff --git a/lib/librte_sched/rte_sched_version.map
> b/lib/librte_sched/rte_sched_version.map
> index 6626a74..cdbaeb7 100644
> --- a/lib/librte_sched/rte_sched_version.map
> +++ b/lib/librte_sched/rte_sched_version.map
> @@ -14,8 +14,10 @@ DPDK_2.0 {
>  	rte_sched_port_enqueue;
>  	rte_sched_port_free;
>  	rte_sched_port_get_memory_footprint;
> +	rte_sched_queue_stats;
>  	rte_sched_queue_read_stats;
>  	rte_sched_subport_config;
> +	rte_sched_subport_stats;
>  	rte_sched_subport_read_stats;
>  	rte_sched_port_pkt_write;
>  	rte_sched_port_pkt_read_tree_path;
> --
> 2.1.4

If we plan to obsolete API function rte_sched_queue_read_stats() and have people use the new API function rte_sched_queue_stats(), we should replace every usage of the obsolete function with call to new function. We need to do this in examples/qos_sched and app/test.