Re: [dpdk-dev] [PATCH v5 02/20] event/sw: add new software-only eventdev driver

[Jerin Jacob <jerin.jacob@caviumnetworks.com>]

On Fri, Mar 24, 2017 at 04:52:57PM +0000, Harry van Haaren wrote:
> From: Bruce Richardson <bruce.richardson@intel.com>
> 
> This adds the minimal changes to allow a SW eventdev implementation to
> be compiled, linked and created at run time. The eventdev does nothing,
> but can be created via vdev on commandline, e.g.
> 
>   sudo ./x86_64-native-linuxapp-gcc/app/test --vdev=event_sw0
>   ...
>   PMD: Creating eventdev sw device event_sw0, numa_node=0, sched_quanta=128
>   RTE>>
> 
> Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> Signed-off-by: Harry van Haaren <harry.van.haaren@intel.com>
> ---
>  config/common_base                            |   6 +
>  drivers/event/Makefile                        |   1 +
>  drivers/event/sw/Makefile                     |  66 ++++++++++
>  drivers/event/sw/rte_pmd_evdev_sw_version.map |   3 +
>  drivers/event/sw/sw_evdev.c                   | 177 ++++++++++++++++++++++++++

[snip]

> + *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
> + *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
> + */
> +
> +#include <string.h>
> +
> +#include <rte_vdev.h>
> +#include <rte_memzone.h>
> +#include <rte_kvargs.h>
> +#include <rte_ring.h>
> +
> +#include "sw_evdev.h"
> +
> +#define EVENTDEV_NAME_SW_PMD event_sw
> +#define NUMA_NODE_ARG "numa_node"
> +#define SCHED_QUANTA_ARG "sched_quanta"
> +#define CREDIT_QUANTA_ARG "credit_quanta"
> +
> +static int
> +assign_numa_node(const char *key __rte_unused, const char *value, void *opaque)
> +{
> +	int *socket_id = opaque;
> +	*socket_id = atoi(value);
> +	if (*socket_id > RTE_MAX_NUMA_NODES)

Shouldn't be ">= RTE_MAX_NUMA_NODES" check, as numa_id is from 0 to
RTE_MAX_NUMA_NODES - 1

> +		return -1;
> +	return 0;
> +}
> +
> +static int
> +set_sched_quanta(const char *key __rte_unused, const char *value, void *opaque)
> +{
> +	int *quanta = opaque;
> +	*quanta = atoi(value);
> +	if (*quanta < 0 || *quanta > 4096)

Is quanta == 4096 valid? or It is only from 0 to 4095?

I think, it is nice to set max value as #define value in sw_evdev.h

> +		return -1;
> +	return 0;
> +}
> +
> +static int
> +set_credit_quanta(const char *key __rte_unused, const char *value, void *opaque)
> +{
> +	int *credit = opaque;
> +	*credit = atoi(value);
> +	if (*credit < 0 || *credit > 128)

Same as above comment.

> +		return -1;
> +	return 0;
> +}
> +
> +static int
> +sw_probe(const char *name, const char *params)
> +{
> +	static const struct rte_eventdev_ops evdev_sw_ops = {
> +	};
> +
> +	static const char *const args[] = {
> +		NUMA_NODE_ARG,
> +		SCHED_QUANTA_ARG,
> +		CREDIT_QUANTA_ARG,
> +		NULL
> +	};
> +	struct rte_eventdev *dev;
> +	struct sw_evdev *sw;
> +	int socket_id = rte_socket_id();
> +	int sched_quanta  = SW_DEFAULT_SCHED_QUANTA;
> +	int credit_quanta = SW_DEFAULT_CREDIT_QUANTA;
> +
> +	if (params != NULL && params[0] != '\0') {
> +		struct rte_kvargs *kvlist = rte_kvargs_parse(params, args);
> +
> +		if (!kvlist) {
> +			SW_LOG_INFO(
> +				"Ignoring unsupported parameters when creating device '%s'\n",
> +				name);
> +		} else {
> +			int ret = rte_kvargs_process(kvlist, NUMA_NODE_ARG,
> +					assign_numa_node, &socket_id);
> +			if (ret != 0) {
> +				SW_LOG_ERR(
> +					"%s: Error parsing numa node parameter",
> +					name);
> +				rte_kvargs_free(kvlist);
> +				return ret;
> +			}
> +
> +			ret = rte_kvargs_process(kvlist, SCHED_QUANTA_ARG,
> +					set_sched_quanta, &sched_quanta);
> +			if (ret != 0) {
> +				SW_LOG_ERR(
> +					"%s: Error parsing sched quanta parameter",
> +					name);
> +				rte_kvargs_free(kvlist);
> +				return ret;
> +			}
> +
> +			ret = rte_kvargs_process(kvlist, CREDIT_QUANTA_ARG,
> +					set_credit_quanta, &credit_quanta);
> +			if (ret != 0) {
> +				SW_LOG_ERR(
> +					"%s: Error parsing credit quanta parameter",
> +					name);
> +				rte_kvargs_free(kvlist);
> +				return ret;
> +			}
> +
> +			rte_kvargs_free(kvlist);
> +		}
> +	}
> +
> +	SW_LOG_INFO(

An extra line here may be not required here.

> +			"Creating eventdev sw device %s, numa_node=%d, sched_quanta=%d, credit_quanta=%d\n",
> +			name, socket_id, sched_quanta, credit_quanta);
> +
> +	dev = rte_event_pmd_vdev_init(name,
> +			sizeof(struct sw_evdev), socket_id);
> +	if (dev == NULL) {
> +		SW_LOG_ERR("eventdev vdev init() failed");
> +		return -EFAULT;
> +	}
> +	dev->dev_ops = &evdev_sw_ops;
> +
> +	sw = dev->data->dev_private;
> +	sw->data = dev->data;
> +
> +	/* copy values passed from vdev command line to instance */
> +	sw->credit_update_quanta = credit_quanta;
> +	sw->sched_quanta = sched_quanta;
> +
> +	return 0;
> +}
> +
> +static int
> +sw_remove(const char *name)
> +{
> +	if (name == NULL)
> +		return -EINVAL;
> +
> +	SW_LOG_INFO("Closing eventdev sw device %s\n", name);
> +
> +	return rte_event_pmd_vdev_uninit(name);
> +}
> +
> +static struct rte_vdev_driver evdev_sw_pmd_drv = {
> +	.probe = sw_probe,
> +	.remove = sw_remove
> +};
> +
> +RTE_PMD_REGISTER_VDEV(EVENTDEV_NAME_SW_PMD, evdev_sw_pmd_drv);
> +RTE_PMD_REGISTER_PARAM_STRING(event_sw, NUMA_NODE_ARG "=<int> "
> +		SCHED_QUANTA_ARG "=<int>" CREDIT_QUANTA_ARG "=<int>");

With suggested changes,

Acked-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>