[ovs-dev] [PATCH v3 4/6] dpif-netdev: Change rxq_scheduling to use rxq processing cycles.

Greg Rose gvrose8192 at gmail.com
Fri Aug 4 21:31:45 UTC 2017


On 08/01/2017 08:58 AM, Kevin Traynor wrote:
> Previously rxqs were assigned to pmds by round robin in
> port/queue order.
>
> Now that we have the processing cycles used for existing rxqs,
> use that information to try and produced a better balanced
> distribution of rxqs across pmds. i.e. given multiple pmds, the
> rxqs which have consumed the largest amount of processing cycles
> will be placed on different pmds.
>
> The rxqs are sorted by their processing cycles and assigned (in
> sorted order) round robin across pmds.
>
> Signed-off-by: Kevin Traynor <ktraynor at redhat.com>

Kevin,

Thanks for your work on openvswitch.

Unfortunately, this patch fails when applied to the master branch.  I didn't see a 'From:' sha id so I don't know which commit to base this series upon.

Here's the error:

Applying: dpif-netdev: Count the rxq processing cycles for an rxq.
Applying patch #796309 using 'git am'
Description: [ovs-dev,v3,4/6] dpif-netdev: Change rxq_scheduling to use rxq processing cycles.
Applying: dpif-netdev: Change rxq_scheduling to use rxq processing cycles.
error: patch failed: lib/dpif-netdev.c:3306
error: lib/dpif-netdev.c: patch does not apply
Patch failed at 0001 dpif-netdev: Change rxq_scheduling to use rxq processing cycles.

I guess we need the series to be rebased.

Thanks,

- Greg

> ---
>   Documentation/howto/dpdk.rst |  7 +++++
>   lib/dpif-netdev.c            | 73 +++++++++++++++++++++++++++++++++++---------
>   2 files changed, 66 insertions(+), 14 deletions(-)
>
> diff --git a/Documentation/howto/dpdk.rst b/Documentation/howto/dpdk.rst
> index af01d3e..a969285 100644
> --- a/Documentation/howto/dpdk.rst
> +++ b/Documentation/howto/dpdk.rst
> @@ -119,4 +119,11 @@ After that PMD threads on cores where RX queues was pinned will become
>     thread.
>
> +If pmd-rxq-affinity is not set for rxqs, they will be assigned to pmds (cores)
> +automatically. The processing cycles that have been required for each rxq
> +will be used where known to assign rxqs with the highest consumption of
> +processing cycles to different pmds.
> +
> +Rxq to pmds assignment takes place whenever there are configuration changes.
> +
>   QoS
>   ---
> diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
> index 25a521a..a05e586 100644
> --- a/lib/dpif-netdev.c
> +++ b/lib/dpif-netdev.c
> @@ -3295,8 +3295,29 @@ rr_numa_list_destroy(struct rr_numa_list *rr)
>   }
>
> +/* Sort Rx Queues by the processing cycles they are consuming. */
> +static int
> +rxq_cycle_sort(const void *a, const void *b)
> +{
> +    struct dp_netdev_rxq * qa;
> +    struct dp_netdev_rxq * qb;
> +
> +    qa = *(struct dp_netdev_rxq **) a;
> +    qb = *(struct dp_netdev_rxq **) b;
> +
> +    if (dp_netdev_rxq_get_cycles(qa, RXQ_CYCLES_PROC_LAST) >=
> +            dp_netdev_rxq_get_cycles(qb, RXQ_CYCLES_PROC_LAST)) {
> +        return -1;
> +    }
> +
> +    return 1;
> +}
> +
>   /* Assign pmds to queues.  If 'pinned' is true, assign pmds to pinned
>    * queues and marks the pmds as isolated.  Otherwise, assign non isolated
>    * pmds to unpinned queues.
>    *
> + * If 'pinned' is false queues will be sorted by processing cycles they are
> + * consuming and then assigned to pmds in round robin order.
> + *
>    * The function doesn't touch the pmd threads, it just stores the assignment
>    * in the 'pmd' member of each rxq. */
> @@ -3306,18 +3327,14 @@ rxq_scheduling(struct dp_netdev *dp, bool pinned) OVS_REQUIRES(dp->port_mutex)
>       struct dp_netdev_port *port;
>       struct rr_numa_list rr;
> -
> -    rr_numa_list_populate(dp, &rr);
> +    struct dp_netdev_rxq ** rxqs = NULL;
> +    int i, n_rxqs = 0;
> +    struct rr_numa *numa = NULL;
> +    int numa_id;
>
>       HMAP_FOR_EACH (port, node, &dp->ports) {
> -        struct rr_numa *numa;
> -        int numa_id;
> -
>           if (!netdev_is_pmd(port->netdev)) {
>               continue;
>           }
>
> -        numa_id = netdev_get_numa_id(port->netdev);
> -        numa = rr_numa_list_lookup(&rr, numa_id);
> -
>           for (int qid = 0; qid < port->n_rxq; qid++) {
>               struct dp_netdev_rxq *q = &port->rxqs[qid];
> @@ -3337,17 +3354,45 @@ rxq_scheduling(struct dp_netdev *dp, bool pinned) OVS_REQUIRES(dp->port_mutex)
>                   }
>               } else if (!pinned && q->core_id == OVS_CORE_UNSPEC) {
> -                if (!numa) {
> -                    VLOG_WARN("There's no available (non isolated) pmd thread "
> -                              "on numa node %d. Queue %d on port \'%s\' will "
> -                              "not be polled.",
> -                              numa_id, qid, netdev_get_name(port->netdev));
> +                if (n_rxqs == 0) {
> +                    rxqs = xmalloc(sizeof *rxqs);
>                   } else {
> -                    q->pmd = rr_numa_get_pmd(numa);
> +                    rxqs = xrealloc(rxqs, sizeof *rxqs * (n_rxqs + 1));
>                   }
> +                /* Store the queue. */
> +                rxqs[n_rxqs++] = q;
>               }
>           }
>       }
>
> +    if (n_rxqs > 1) {
> +        /* Sort the queues in order of the processing cycles
> +         * they consumed during their last pmd interval. */
> +        qsort(rxqs, n_rxqs, sizeof *rxqs, rxq_cycle_sort);
> +    }
> +
> +    rr_numa_list_populate(dp, &rr);
> +    /* Assign the sorted queues to pmds in round robin. */
> +    for (i = 0; i < n_rxqs; i++) {
> +        numa_id = netdev_get_numa_id(rxqs[i]->port->netdev);
> +        numa = rr_numa_list_lookup(&rr, numa_id);
> +        if (!numa) {
> +            VLOG_WARN("There's no available (non isolated) pmd thread "
> +                      "on numa node %d. Queue %d on port \'%s\' will "
> +                      "not be polled.",
> +                      numa_id, netdev_rxq_get_queue_id(rxqs[i]->rx),
> +                      netdev_get_name(rxqs[i]->port->netdev));
> +            continue;
> +        }
> +        rxqs[i]->pmd = rr_numa_get_pmd(numa);
> +        VLOG_INFO("Core %d on numa node %d assigned port \'%s\' "
> +                  "rx queue %d (measured processing cycles %"PRIu64").",
> +                  rxqs[i]->pmd->core_id, numa_id,
> +                  netdev_rxq_get_name(rxqs[i]->rx),
> +                  netdev_rxq_get_queue_id(rxqs[i]->rx),
> +                  dp_netdev_rxq_get_cycles(rxqs[i], RXQ_CYCLES_PROC_LAST));
> +    }
> +
>       rr_numa_list_destroy(&rr);
> +    free(rxqs);
>   }
>
>



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