[ovs-dev] [PATCH] upcall: Log failure to flow_put for dpif-netlink.

[Jarno Rajahalme]

Looks goos except for a small style nit below.

Acked-by: Jarno Rajahalme <jarno at ovn.org>


> On Aug 18, 2016, at 2:50 PM, Joe Stringer <joe at ovn.org> wrote:
> 
> Previously these errors were only logged for dpif-netdev. Make it
> consistent by merging the code for both datapaths.
> 
> Signed-off-by: Joe Stringer <joe at ovn.org>
> ---
> This could be handy for debugging on v2.6, so modulo any objections I
> intend to apply it there too.
> ---
> ofproto/ofproto-dpif-upcall.c | 57 +++++++++++++++++++++----------------------
> 1 file changed, 28 insertions(+), 29 deletions(-)
> 
> diff --git a/ofproto/ofproto-dpif-upcall.c b/ofproto/ofproto-dpif-upcall.c
> index c83df9ea8648..9e1730b2c6d5 100644
> --- a/ofproto/ofproto-dpif-upcall.c
> +++ b/ofproto/ofproto-dpif-upcall.c
> @@ -1133,6 +1133,32 @@ upcall_uninit(struct upcall *upcall)
>     }
> }
> 
> +/* If there are less flows than the limit, and this is a miss upcall which
> + *
> + *      - Has no recirc_id, OR
> + *      - Has a recirc_id and we can get a reference on the recirc ctx,
> + *
> + * Then we should install the flow (true). Otherwise, return false. */
> +static bool should_install_flow(struct udpif *udpif, struct upcall *upcall)

“static bool” should be on the previous line.

> +{
> +    unsigned int flow_limit;
> +
> +    if (upcall->type != DPIF_UC_MISS) {
> +        return false;
> +    } else if (upcall->recirc && !upcall->have_recirc_ref) {
> +        VLOG_WARN_RL(&rl, "upcall: no reference for recirc flow");
> +        return false;
> +    }
> +
> +    atomic_read_relaxed(&udpif->flow_limit, &flow_limit);
> +    if (udpif_get_n_flows(udpif) >= flow_limit) {
> +        VLOG_WARN_RL(&rl, "upcall: datapath flow limit reached");
> +        return false;
> +    }
> +
> +    return true;
> +}
> +
> static int
> upcall_cb(const struct dp_packet *packet, const struct flow *flow, ovs_u128 *ufid,
>           unsigned pmd_id, enum dpif_upcall_type type,
> @@ -1141,13 +1167,11 @@ upcall_cb(const struct dp_packet *packet, const struct flow *flow, ovs_u128 *ufi
> {
>     static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 1);
>     struct udpif *udpif = aux;
> -    unsigned int flow_limit;
>     struct upcall upcall;
>     bool megaflow;
>     int error;
> 
>     atomic_read_relaxed(&enable_megaflows, &megaflow);
> -    atomic_read_relaxed(&udpif->flow_limit, &flow_limit);
> 
>     error = upcall_receive(&upcall, udpif->backer, packet, type, userdata,
>                            flow, 0, ufid, pmd_id);
> @@ -1169,16 +1193,7 @@ upcall_cb(const struct dp_packet *packet, const struct flow *flow, ovs_u128 *ufi
>         flow_wildcards_init_for_packet(wc, flow);
>     }
> 
> -    if (udpif_get_n_flows(udpif) >= flow_limit) {
> -        VLOG_WARN_RL(&rl, "upcall_cb failure: datapath flow limit reached");
> -        error = ENOSPC;
> -        goto out;
> -    }
> -
> -    /* Prevent miss flow installation if the key has recirculation ID but we
> -     * were not able to get a reference on it. */
> -    if (type == DPIF_UC_MISS && upcall.recirc && !upcall.have_recirc_ref) {
> -        VLOG_WARN_RL(&rl, "upcall_cb failure: no reference for recirc flow");
> +    if (!should_install_flow(udpif, &upcall)) {
>         error = ENOSPC;
>         goto out;
>     }
> @@ -1297,13 +1312,7 @@ handle_upcalls(struct udpif *udpif, struct upcall *upcalls,
> {
>     struct dpif_op *opsp[UPCALL_MAX_BATCH * 2];
>     struct ukey_op ops[UPCALL_MAX_BATCH * 2];
> -    unsigned int flow_limit;
>     size_t n_ops, n_opsp, i;
> -    bool may_put;
> -
> -    atomic_read_relaxed(&udpif->flow_limit, &flow_limit);
> -
> -    may_put = udpif_get_n_flows(udpif) < flow_limit;
> 
>     /* Handle the packets individually in order of arrival.
>      *
> @@ -1321,17 +1330,7 @@ handle_upcalls(struct udpif *udpif, struct upcall *upcalls,
>         const struct dp_packet *packet = upcall->packet;
>         struct ukey_op *op;
> 
> -        /* Do not install a flow into the datapath if:
> -         *
> -         *    - The datapath already has too many flows.
> -         *
> -         *    - We received this packet via some flow installed in the kernel
> -         *      already.
> -         *
> -         *    - Upcall was a recirculation but we do not have a reference to
> -         *      to the recirculation ID. */
> -        if (may_put && upcall->type == DPIF_UC_MISS &&
> -            (!upcall->recirc || upcall->have_recirc_ref)) {
> +        if (should_install_flow(udpif, upcall)) {
>             struct udpif_key *ukey = upcall->ukey;
> 
>             upcall->ukey_persists = true;
> -- 
> 2.9.2
>