Re: [PATCH V3 2/4] RDMA/core: Introduce shared CQ pool API

[Yamin Friedman <yaminf@mellanox.com>]

On 5/20/2020 9:19 AM, Devesh Sharma wrote:
>
>> +
>> +static int ib_alloc_cqs(struct ib_device *dev, int nr_cqes,
>> +                       enum ib_poll_context poll_ctx)
>> +{
>> +       LIST_HEAD(tmp_list);
>> +       struct ib_cq *cq;
>> +       unsigned long flags;
>> +       int nr_cqs, ret, i;
>> +
>> +       /*
>> +        * Allocated at least as many CQEs as requested, and otherwise
>> +        * a reasonable batch size so that we can share CQs between
>> +        * multiple users instead of allocating a larger number of CQs.
>> +        */
>> +       nr_cqes = min(dev->attrs.max_cqe, max(nr_cqes, IB_MAX_SHARED_CQ_SZ));
>> +       nr_cqs = min_t(int, dev->num_comp_vectors, num_online_cpus());
> No WARN() or return with failure as pointed by Leon and me. Has
> anything else changes elsewhere?

Hey Devesh,

I am not sure what you are referring to, could you please clarify?

>
>> +       for (i = 0; i < nr_cqs; i++) {
>> +               cq = ib_alloc_cq(dev, NULL, nr_cqes, i, poll_ctx);
>> +               if (IS_ERR(cq)) {
>> +                       ret = PTR_ERR(cq);
>> +                       goto out_free_cqs;
>> +               }
>> +               cq->shared = true;
>> +               list_add_tail(&cq->pool_entry, &tmp_list);
>> +       }
>> +
>> +       spin_lock_irqsave(&dev->cq_pools_lock, flags);
>> +       list_splice(&tmp_list, &dev->cq_pools[poll_ctx - 1]);
>> +       spin_unlock_irqrestore(&dev->cq_pools_lock, flags);
>> +
>> +       return 0;
>> +
>> +out_free_cqs:
>> +       list_for_each_entry(cq, &tmp_list, pool_entry) {
>> +               cq->shared = false;
>> +               ib_free_cq(cq);
>> +       }
>> +       return ret;
>> +}
>> +
>>