Re: [dpdk-dev] [PATCH] mbuf: implement generic format for sched field

["Singh, Jasvinder" <jasvinder.singh@intel.com>]

<snip>
> 
> > diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
> > index 3dbc6695e..98428bd21 100644
> > --- a/lib/librte_mbuf/rte_mbuf.h
> > +++ b/lib/librte_mbuf/rte_mbuf.h
> > @@ -575,12 +575,10 @@ struct rte_mbuf {
> >  				 */
> >  			} fdir;	/**< Filter identifier if FDIR enabled */
> >  			struct {
> > -				uint32_t lo;
> > -				uint32_t hi;
> > -				/**< The event eth Tx adapter uses this field
> > -				 * to store Tx queue id.
> > -				 * @see
> > rte_event_eth_tx_adapter_txq_set()
> > -				 */
> > +				uint32_t queue_id;   /**< Queue ID. */
> > +				uint8_t traffic_class;   /**< Traffic class ID. */
> 
> We should add comment here that traffic class 0 is the highest priority traffic
> class.

Will add the suggested comment.

> 
> > +				uint8_t color;   /**< Color. */
> 
> We should create a new file rte_color.h in a common place
> (librte_eal/common/include) to consolidate the color definition, which is
> currently replicated in too many places, such as: rte_meter.h, rte_mtr.h,
> rte_tm.h.
> 
> We should include the rte_color.h file here (and in the above header files)
> 
> We should also document the link between this field and the color enum type
> (@see ...).

Replacing the existing color definition with the above suggested one in rte_meter.h (librte_meter)
would be ABI break. We can do it separately through different patch.

> 
> > +				uint16_t reserved;   /**< Reserved. */
> >  			} sched;          /**< Hierarchical scheduler */
> >  			/**< User defined tags. See
> > rte_distributor_process() */
> >  			uint32_t usr;
> 
> We should also add trivial inline functions to read/write these mbuf fields as
> part of this header file. We want to discourage people from accessing these
> fields directly.
> 
> Besides the functions to read/write each field individually, we should also
> have a function to read all the sched fields in one operation, as well as another
> one to write all the sched fields in one operation.

Will create inline functions for reading and writing each field separately and jointly.  
> 
> > diff --git a/lib/librte_pipeline/rte_table_action.c
> > b/lib/librte_pipeline/rte_table_action.c
> > index 7c7c8dd82..99f2d779b 100644
> > --- a/lib/librte_pipeline/rte_table_action.c
> > +++ b/lib/librte_pipeline/rte_table_action.c
> > @@ -108,12 +108,12 @@ mtr_cfg_check(struct rte_table_action_mtr_config
> > *mtr)
> >  }
> >
> >  #define MBUF_SCHED_QUEUE_TC_COLOR(queue, tc, color)        \
> > -	((uint16_t)((((uint64_t)(queue)) & 0x3) |          \
> > -	((((uint64_t)(tc)) & 0x3) << 2) |                  \
> > -	((((uint64_t)(color)) & 0x3) << 4)))
> > +	((uint64_t)((((uint64_t)(queue)) & 0xffffffff) |          \
> > +	((((uint64_t)(tc)) & 0xff) << 32) |                  \
> > +	((((uint64_t)(color)) & 0xff) << 40)))
> >
> >  #define MBUF_SCHED_COLOR(sched, color)                     \
> > -	(((sched) & (~0x30LLU)) | ((color) << 4))
> > +	((uint64_t)((sched) & (~0xff000000LLU)) | (((uint64_t)(color)) <<
> > +40))
> >
> 
> Given the read/write mbuf->sched field functions, the above two macros are
> no longer needed.

Will remove this.

> >  struct mtr_trtcm_data {
> >  	struct rte_meter_trtcm trtcm;
> > @@ -176,7 +176,7 @@ mtr_data_size(struct rte_table_action_mtr_config
> > *mtr)
> >  struct dscp_table_entry_data {
> >  	enum rte_meter_color color;
> >  	uint16_t tc;
> > -	uint16_t queue_tc_color;
> > +	uint32_t queue;
> >  };
> >
> >  struct dscp_table_data {
> > @@ -368,7 +368,6 @@ tm_cfg_check(struct rte_table_action_tm_config
> > *tm)
> >  }
> >
> >  struct tm_data {
> > -	uint16_t queue_tc_color;
> >  	uint16_t subport;
> >  	uint32_t pipe;
> >  } __attribute__((__packed__));
> > @@ -397,26 +396,40 @@ tm_apply(struct tm_data *data,
> >  		return status;
> >
> >  	/* Apply */
> > -	data->queue_tc_color = 0;
> >  	data->subport = (uint16_t) p->subport_id;
> >  	data->pipe = p->pipe_id;
> >
> >  	return 0;
> >  }
> >
> > +static uint32_t
> > +tm_sched_qindex(struct tm_data *data,
> > +	struct dscp_table_entry_data *dscp,
> > +	struct rte_table_action_tm_config *cfg) {
> > +
> > +	uint32_t result;
> > +
> > +	result = data->subport * cfg->n_pipes_per_subport + data->pipe;
> 
> Since n_subports_per_pipe and n_pipes_per_subport are enforced to be
> power of 2, we should replace multiplication/division with shift left/right. We
> probably need to store log2 correspondents in the action context.

Thanks. Will store log2 component in action context and use them in run time for shift operations.

> > +	result = result * RTE_TABLE_ACTION_TC_MAX + dscp->tc;
> > +	result = result * RTE_TABLE_ACTION_TC_QUEUE_MAX + dscp-
> > >queue;
> > +
> > +	return result;
> > +}
> > +
> >  static __rte_always_inline void
> >  pkt_work_tm(struct rte_mbuf *mbuf,
> >  	struct tm_data *data,
> >  	struct dscp_table_data *dscp_table,
> > -	uint32_t dscp)
> > +	uint32_t dscp,
> > +	struct rte_table_action_tm_config *cfg)
> >  {
> >  	struct dscp_table_entry_data *dscp_entry = &dscp_table-
> > >entry[dscp];
> > -	struct tm_data *sched_ptr = (struct tm_data *) &mbuf->hash.sched;
> > -	struct tm_data sched;
> > +	uint64_t *sched_ptr = (uint64_t *) &mbuf->hash.sched;
> > +	uint32_t queue = tm_sched_qindex(data, dscp_entry, cfg);
> >
> > -	sched = *data;
> > -	sched.queue_tc_color = dscp_entry->queue_tc_color;
> > -	*sched_ptr = sched;
> > +	*sched_ptr = MBUF_SCHED_QUEUE_TC_COLOR(queue,
> > +			dscp_entry->tc,
> > +			dscp_entry->color);
> >  }
> >
> >  /**
> > @@ -2580,17 +2593,13 @@ rte_table_action_dscp_table_update(struct
> > rte_table_action *action,
> >  			&action->dscp_table.entry[i];
> >  		struct rte_table_action_dscp_table_entry *entry =
> >  			&table->entry[i];
> > -		uint16_t queue_tc_color =
> > -			MBUF_SCHED_QUEUE_TC_COLOR(entry-
> > >tc_queue_id,
> > -				entry->tc_id,
> > -				entry->color);
> >
> >  		if ((dscp_mask & (1LLU << i)) == 0)
> >  			continue;
> >
> >  		data->color = entry->color;
> >  		data->tc = entry->tc_id;
> > -		data->queue_tc_color = queue_tc_color;
> > +		data->queue = entry->tc_queue_id;
> >  	}
> >
> >  	return 0;
> > @@ -2882,7 +2891,8 @@ pkt_work(struct rte_mbuf *mbuf,
> >  		pkt_work_tm(mbuf,
> >  			data,
> >  			&action->dscp_table,
> > -			dscp);
> > +			dscp,
> > +			&cfg->tm);
> >  	}
> >
> >  	if (cfg->action_mask & (1LLU << RTE_TABLE_ACTION_DECAP)) { @@
> > -3108,22 +3118,26 @@ pkt4_work(struct rte_mbuf **mbufs,
> >  		pkt_work_tm(mbuf0,
> >  			data0,
> >  			&action->dscp_table,
> > -			dscp0);
> > +			dscp0,
> > +			&cfg->tm);
> >
> >  		pkt_work_tm(mbuf1,
> >  			data1,
> >  			&action->dscp_table,
> > -			dscp1);
> > +			dscp1,
> > +			&cfg->tm);
> >
> >  		pkt_work_tm(mbuf2,
> >  			data2,
> >  			&action->dscp_table,
> > -			dscp2);
> > +			dscp2,
> > +			&cfg->tm);
> >
> >  		pkt_work_tm(mbuf3,
> >  			data3,
> >  			&action->dscp_table,
> > -			dscp3);
> > +			dscp3,
> > +			&cfg->tm);
> >  	}
> >
> >  	if (cfg->action_mask & (1LLU << RTE_TABLE_ACTION_DECAP)) { diff
> > --git a/lib/librte_sched/Makefile b/lib/librte_sched/Makefile index
> > 46c53ed71..644fd9d15 100644
> > --- a/lib/librte_sched/Makefile
> > +++ b/lib/librte_sched/Makefile
> > @@ -18,7 +18,7 @@ LDLIBS += -lrte_timer
> >
> >  EXPORT_MAP := rte_sched_version.map
> >
> > -LIBABIVER := 1
> > +LIBABIVER := 2
> >
> >  #
> >  # all source are stored in SRCS-y
> > diff --git a/lib/librte_sched/rte_sched.c
> > b/lib/librte_sched/rte_sched.c index 587d5e602..7bf4d6400 100644
> > --- a/lib/librte_sched/rte_sched.c
> > +++ b/lib/librte_sched/rte_sched.c
> > @@ -128,22 +128,6 @@ enum grinder_state {
> >  	e_GRINDER_READ_MBUF
> >  };
> >
> > -/*
> > - * Path through the scheduler hierarchy used by the scheduler enqueue
> > - * operation to identify the destination queue for the current
> > - * packet. Stored in the field pkt.hash.sched of struct rte_mbuf of
> > - * each packet, typically written by the classification stage and
> > read
> > - * by scheduler enqueue.
> > - */
> > -struct rte_sched_port_hierarchy {
> > -	uint16_t queue:2;                /**< Queue ID (0 .. 3) */
> > -	uint16_t traffic_class:2;        /**< Traffic class ID (0 .. 3)*/
> > -	uint32_t color:2;                /**< Color */
> > -	uint16_t unused:10;
> > -	uint16_t subport;                /**< Subport ID */
> > -	uint32_t pipe;		         /**< Pipe ID */
> > -};
> > -
> >  struct rte_sched_grinder {
> >  	/* Pipe cache */
> >  	uint16_t pcache_qmask[RTE_SCHED_GRINDER_PCACHE_SIZE];
> > @@ -241,16 +225,12 @@ enum rte_sched_port_array {
> >  	e_RTE_SCHED_PORT_ARRAY_TOTAL,
> >  };
> >
> > -#ifdef RTE_SCHED_COLLECT_STATS
> > -
> >  static inline uint32_t
> >  rte_sched_port_queues_per_subport(struct rte_sched_port *port)  {
> >  	return RTE_SCHED_QUEUES_PER_PIPE * port-
> > >n_pipes_per_subport;
> >  }
> >
> > -#endif
> > -
> >  static inline uint32_t
> >  rte_sched_port_queues_per_port(struct rte_sched_port *port)  { @@
> > -1006,44 +986,50 @@ rte_sched_port_pipe_profile_add(struct
> > rte_sched_port *port,
> >  	return 0;
> >  }
> >
> > +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)
> > +{
> > +	uint32_t result;
> > +
> > +	result = subport * port->n_pipes_per_subport + pipe;
> 
> Since n_subports_per_pipe and n_pipes_per_subport are enforced to be
> power of 2, we should replace multiplication/division with shift left/right.

Will replace with shift operation using log2 of n_subports_per_pipe and n_pipes_per_subport.


> > +	result = result * RTE_SCHED_TRAFFIC_CLASSES_PER_PIPE +
> > traffic_class;
> > +	result = result * RTE_SCHED_QUEUES_PER_TRAFFIC_CLASS + queue;
> > +
> > +	return result;
> > +}
> > +
> >  void
> > -rte_sched_port_pkt_write(struct rte_mbuf *pkt,
> > +rte_sched_port_pkt_write(struct rte_sched_port *port,
> > +			 struct rte_mbuf *pkt,
> >  			 uint32_t subport, uint32_t pipe, uint32_t traffic_class,
> >  			 uint32_t queue, enum rte_meter_color color)  {
> > -	struct rte_sched_port_hierarchy *sched
> > -		= (struct rte_sched_port_hierarchy *) &pkt->hash.sched;
> > -
> > -	RTE_BUILD_BUG_ON(sizeof(*sched) > sizeof(pkt->hash.sched));
> > -
> > -	sched->color = (uint32_t) color;
> > -	sched->subport = subport;
> > -	sched->pipe = pipe;
> > -	sched->traffic_class = traffic_class;
> > -	sched->queue = queue;
> > +	pkt->hash.sched.traffic_class = traffic_class;
> > +	pkt->hash.sched.queue_id = rte_sched_port_qindex(port, subport,
> > pipe,
> > +			traffic_class, queue);
> > +	pkt->hash.sched.color = (uint8_t) color;
> >  }
> >
> >  void
> > -rte_sched_port_pkt_read_tree_path(const struct rte_mbuf *pkt,
> > +rte_sched_port_pkt_read_tree_path(struct rte_sched_port *port,
> > +				  const struct rte_mbuf *pkt,
> >  				  uint32_t *subport, uint32_t *pipe,
> >  				  uint32_t *traffic_class, uint32_t *queue)  {
> > -	const struct rte_sched_port_hierarchy *sched
> > -		= (const struct rte_sched_port_hierarchy *) &pkt-
> > >hash.sched;
> > -
> > -	*subport = sched->subport;
> > -	*pipe = sched->pipe;
> > -	*traffic_class = sched->traffic_class;
> > -	*queue = sched->queue;
> > +	*subport = pkt->hash.sched.queue_id /
> > rte_sched_port_queues_per_subport(port);
> > +	*pipe = pkt->hash.sched.queue_id /
> > RTE_SCHED_QUEUES_PER_PIPE;
> 
> Since n_subports_per_pipe and n_pipes_per_subport are enforced to be
> power of 2, we should replace multiplication/division with shift left/right.


Will do that.

> > +	*traffic_class = pkt->hash.sched.traffic_class;
> > +	*queue = pkt->hash.sched.queue_id %
> > RTE_SCHED_QUEUES_PER_TRAFFIC_CLASS;
> 
> Since RTE_SCHED_QUEUES_PER_TRAFFIC_CLASS is enforced to be a power of
> 2, please replace modulo with bitwise AND of
> (RTE_SCHED_QUEUES_PER_TRAFFIC_CLASS - 1).
> 
> >  }


Will do that.

> >  enum rte_meter_color
> >  rte_sched_port_pkt_read_color(const struct rte_mbuf *pkt)  {
> > -	const struct rte_sched_port_hierarchy *sched
> > -		= (const struct rte_sched_port_hierarchy *) &pkt-
> > >hash.sched;
> > -
> > -	return (enum rte_meter_color) sched->color;
> > +	return (enum rte_meter_color) pkt->hash.sched.color;
> >  }
> 
> Should use the mbuf->sched.color read function to be added in rte_mbuf.h.

Yes. Will change this.

> >  int
> > @@ -1100,18 +1086,6 @@ rte_sched_queue_read_stats(struct
> > rte_sched_port *port,
> >  	return 0;
> >  }
> >
> > -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) -{
> > -	uint32_t result;
> > -
> > -	result = subport * port->n_pipes_per_subport + pipe;
> > -	result = result * RTE_SCHED_TRAFFIC_CLASSES_PER_PIPE +
> > traffic_class;
> > -	result = result * RTE_SCHED_QUEUES_PER_TRAFFIC_CLASS + queue;
> > -
> > -	return result;
> > -
> 
> Since n_subports_per_pipe and n_pipes_per_subport are enforced to be
> power of 2, we should replace multiplication/division with shift left/right.

Will change this as well.


> }
> > -
> >  #ifdef RTE_SCHED_DEBUG
> >
> >  static inline int
> > @@ -1272,11 +1246,8 @@ rte_sched_port_enqueue_qptrs_prefetch0(struct
> > rte_sched_port *port,
> >  #ifdef RTE_SCHED_COLLECT_STATS
> >  	struct rte_sched_queue_extra *qe;
> >  #endif
> > -	uint32_t subport, pipe, traffic_class, queue, qindex;
> > -
> > -	rte_sched_port_pkt_read_tree_path(pkt, &subport, &pipe,
> > &traffic_class, &queue);
> > +	uint32_t qindex = pkt->hash.sched.queue_id;
> 
> Let's use the read function for this mbuf field.

Yes.

> >
> > -	qindex = rte_sched_port_qindex(port, subport, pipe, traffic_class,
> > queue);
> >  	q = port->queue + qindex;
> >  	rte_prefetch0(q);
> >  #ifdef RTE_SCHED_COLLECT_STATS
> > diff --git a/lib/librte_sched/rte_sched.h
> > b/lib/librte_sched/rte_sched.h index 84fa896de..4d9f869eb 100644
> > --- a/lib/librte_sched/rte_sched.h
> > +++ b/lib/librte_sched/rte_sched.h
> > @@ -355,6 +355,8 @@ rte_sched_queue_read_stats(struct rte_sched_port
> > *port,
> >   * Scheduler hierarchy path write to packet descriptor. Typically
> >   * called by the packet classification stage.
> >   *
> > + * @param port
> > + *   Handle to port scheduler instance
> >   * @param pkt
> >   *   Packet descriptor handle
> >   * @param subport
> > @@ -369,7 +371,8 @@ rte_sched_queue_read_stats(struct rte_sched_port
> > *port,
> >   *   Packet color set
> >   */
> >  void
> > -rte_sched_port_pkt_write(struct rte_mbuf *pkt,
> > +rte_sched_port_pkt_write(struct rte_sched_port *port,
> > +			 struct rte_mbuf *pkt,
> >  			 uint32_t subport, uint32_t pipe, uint32_t traffic_class,
> >  			 uint32_t queue, enum rte_meter_color color);
> >
> > @@ -379,6 +382,8 @@ rte_sched_port_pkt_write(struct rte_mbuf *pkt,
> >   * enqueue operation. The subport, pipe, traffic class and queue
> >   * parameters need to be pre-allocated by the caller.
> >   *
> > +  * @param port
> > + *   Handle to port scheduler instance
> >   * @param pkt
> >   *   Packet descriptor handle
> >   * @param subport
> > @@ -392,7 +397,8 @@ rte_sched_port_pkt_write(struct rte_mbuf *pkt,
> >   *
> >   */
> >  void
> > -rte_sched_port_pkt_read_tree_path(const struct rte_mbuf *pkt,
> > +rte_sched_port_pkt_read_tree_path(struct rte_sched_port *port,
> > +				  const struct rte_mbuf *pkt,
> >  				  uint32_t *subport, uint32_t *pipe,
> >  				  uint32_t *traffic_class, uint32_t *queue);
> >
> 
> <snip>
> 
> Regards,
> Cristian



We will work on the suggested changes and send another version. Thank you, Cristian.