[PATCH v2 3/6] RDMA/core: expose affinity mappings per completion vector

[Håkon Bugge]

> On 06 Apr 2017, at 12:36, Sagi Grimberg <sagi at grimberg.me> wrote:
> 
> This will allow ULPs to intelligently locate threads based
> on completion vector cpu affinity mappings. In case the
> driver does not expose a get_vector_affinity callout, return
> NULL so the caller can maintain a fallback logic.
> 
> Reviewed-by: Christoph Hellwig <hch at lst.de>
> Signed-off-by: Sagi Grimberg <sagi at grimberg.me>
> ---
> include/rdma/ib_verbs.h | 24 ++++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
> 
> diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
> index 0f1813c13687..d44b62791c64 100644
> --- a/include/rdma/ib_verbs.h
> +++ b/include/rdma/ib_verbs.h
> @@ -2150,6 +2150,8 @@ struct ib_device {
> 	 */
> 	int (*get_port_immutable)(struct ib_device *, u8, struct ib_port_immutable *);
> 	void (*get_dev_fw_str)(struct ib_device *, char *str, size_t str_len);
> +	const struct cpumask *(*get_vector_affinity)(struct ib_device *ibdev,
> +						     int comp_vector);
> };
> 
> struct ib_client {
> @@ -3377,4 +3379,26 @@ void ib_drain_qp(struct ib_qp *qp);
> 
> int ib_resolve_eth_dmac(struct ib_device *device,
> 			struct ib_ah_attr *ah_attr);
> +
> +/**
> + * ib_get_vector_affinity - Get the affinity mappings of a given completion
> + *   vector
> + * @device:         the rdma device
> + * @comp_vector:    index of completion vector
> + *
> + * Returns NULL on failure, otherwise a corresponding cpu map of the
> + * completion vector (returns all-cpus map if the device driver doesn't
> + * implement get_vector_affinity).
> + */
> +static inline const struct cpumask *
> +ib_get_vector_affinity(struct ib_device *device, int comp_vector)
> +{
> +	if (comp_vector > device->num_comp_vectors ||

Should the valid comp_vector range be from 0 (zero) to (num_comp_vectors - 1) ?

Otherwise,

Reviewed-by: Håkon Bugge <haakon.bugge at oracle.com>


Thxs, Håkon


> +	    !device->get_vector_affinity)
> +		return NULL;
> +
> +	return device->get_vector_affinity(device, comp_vector);
> +
> +}
> +
> #endif /* IB_VERBS_H */
> -- 
> 2.7.4
> 
> --
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