Re: [dpdk-dev] [PATCH 09/10] eal: get relative core index

[Bruce Richardson <bruce.richardson@intel.com>]

On Sat, Nov 22, 2014 at 10:43:41PM +0100, Thomas Monjalon wrote:
> From: Patrick Lu <Patrick.Lu@intel.com>
> 
> EAL -c option allows the user to enable any lcore in the system.
> Often times, the user app wants to know 1st enabled core, 2nd
> enabled core, etc, rather than phyical core ID (rte_lcore_id().)
> 
> The new API rte_lcore_index() will return an index from enabled lcores
> starting from zero.
> 
> Signed-off-by: Patrick Lu <patrick.lu@intel.com>
> Signed-off-by: Thomas Monjalon <thomas.monjalon@6wind.com>

I think this is good as far as it goes, but I think an extra API to get the
lcore with the given index would be a great extension to this. That would
allow you to do:

rte_eal_remote_launch(func0, arg0, rte_lcore_with_index(0));
rte_eal_remote_launch(func1, arg1, rte_lcore_with_index(1));
...

However, as a good start, I think this should be applied for now, so...

Acked-by: Bruce Richardson <bruce.richardson@intel.com>

> ---
>  lib/librte_eal/common/eal_common_options.c | 13 ++++++++++---
>  lib/librte_eal/common/include/rte_lcore.h  | 20 ++++++++++++++++++++
>  2 files changed, 30 insertions(+), 3 deletions(-)
> 
> diff --git a/lib/librte_eal/common/eal_common_options.c b/lib/librte_eal/common/eal_common_options.c
> index 18d03e3..c9df8f5 100644
> --- a/lib/librte_eal/common/eal_common_options.c
> +++ b/lib/librte_eal/common/eal_common_options.c
> @@ -185,19 +185,23 @@ eal_parse_coremask(const char *coremask)
>  					return -1;
>  				}
>  				cfg->lcore_role[idx] = ROLE_RTE;
> +				lcore_config[idx].core_index = count;
>  				if (count == 0)
>  					cfg->master_lcore = idx;
>  				count++;
>  			} else {
>  				cfg->lcore_role[idx] = ROLE_OFF;
> +				lcore_config[idx].core_index = -1;
>  			}
>  		}
>  	}
>  	for (; i >= 0; i--)
>  		if (coremask[i] != '0')
>  			return -1;
> -	for (; idx < RTE_MAX_LCORE; idx++)
> +	for (; idx < RTE_MAX_LCORE; idx++) {
>  		cfg->lcore_role[idx] = ROLE_OFF;
> +		lcore_config[idx].core_index = -1;
> +	}
>  	if (count == 0)
>  		return -1;
>  	/* Update the count of enabled logical cores of the EAL configuration */
> @@ -225,9 +229,11 @@ eal_parse_corelist(const char *corelist)
>  	while ((i > 0) && isblank(corelist[i - 1]))
>  		i--;
>  
> -	/* Reset core roles */
> -	for (idx = 0; idx < RTE_MAX_LCORE; idx++)
> +	/* Reset config */
> +	for (idx = 0; idx < RTE_MAX_LCORE; idx++) {
>  		cfg->lcore_role[idx] = ROLE_OFF;
> +		lcore_config[idx].core_index = -1;
> +	}
>  
>  	/* Get list of cores */
>  	min = RTE_MAX_LCORE;
> @@ -250,6 +256,7 @@ eal_parse_corelist(const char *corelist)
>  				min = idx;
>  			for (idx = min; idx <= max; idx++) {
>  				cfg->lcore_role[idx] = ROLE_RTE;
> +				lcore_config[idx].core_index = count;
>  				if (count == 0)
>  					cfg->master_lcore = idx;
>  				count++;
> diff --git a/lib/librte_eal/common/include/rte_lcore.h b/lib/librte_eal/common/include/rte_lcore.h
> index a0b4356..49b2c03 100644
> --- a/lib/librte_eal/common/include/rte_lcore.h
> +++ b/lib/librte_eal/common/include/rte_lcore.h
> @@ -64,6 +64,7 @@ struct lcore_config {
>  	volatile enum rte_lcore_state_t state; /**< lcore state */
>  	unsigned socket_id;        /**< physical socket id for this lcore */
>  	unsigned core_id;          /**< core number on socket for this lcore */
> +	int core_index;            /**< relative index, starting from 0 */
>  };
>  
>  /**
> @@ -110,6 +111,25 @@ rte_lcore_count(void)
>  }
>  
>  /**
> + * Return the index of the lcore starting from zero.
> + * The order is physical or given by command line (-l option).
> + *
> + * @param lcore_id
> + *   The targeted lcore, or -1 for the current one.
> + * @return
> + *   The relative index, or -1 if not enabled.
> + */
> +static inline int
> +rte_lcore_index(int lcore_id)
> +{
> +	if (lcore_id >= RTE_MAX_LCORE)
> +		return -1;
> +	if (lcore_id < 0)
> +		lcore_id = rte_lcore_id();
> +	return lcore_config[lcore_id].core_index;
> +}
> +
> +/**
>   * Return the ID of the physical socket of the logical core we are
>   * running on.
>   * @return
> -- 
> 2.1.3
>