[ovs-dev] [PATCH] netdev-offload-tc: Use single thread for probing tc features

[Ilya Maximets]

On 11/2/20 1:07 PM, Roi Dayan wrote:
> There is no need for a thread start per probe.

This sounds like we're actually starting some pthreads here.
I think, it should be something like:
"There is no need for a 'once' variable per probe."

Same for the patch name. E.g.
"netdev-offload-tc: Use single 'once' variable for probing tc features."

One minor comment inline.

Best regards, Ilya Maximets.

> 
> Signed-off-by: Roi Dayan <roid at nvidia.com>
> Reviewed-by: Paul Blakey <paulb at mellanox.com>
> ---
>  lib/netdev-offload-tc.c | 11 +++--------
>  1 file changed, 3 insertions(+), 8 deletions(-)
> 
> diff --git a/lib/netdev-offload-tc.c b/lib/netdev-offload-tc.c
> index e828a8683910..53662ef3f0e6 100644
> --- a/lib/netdev-offload-tc.c
> +++ b/lib/netdev-offload-tc.c
> @@ -1988,8 +1988,7 @@ probe_tc_block_support(int ifindex)
>  static int
>  netdev_tc_init_flow_api(struct netdev *netdev)
>  {
> -    static struct ovsthread_once multi_mask_once = OVSTHREAD_ONCE_INITIALIZER;
> -    static struct ovsthread_once block_once = OVSTHREAD_ONCE_INITIALIZER;
> +    static struct ovsthread_once once = OVSTHREAD_ONCE_INITIALIZER;
>      enum tc_qdisc_hook hook = get_tc_qdisc_hook(netdev);
>      uint32_t block_id = 0;
>      struct tcf_id id;
> @@ -2014,16 +2013,12 @@ netdev_tc_init_flow_api(struct netdev *netdev)
>      /* make sure there is no ingress/egress qdisc */
>      tc_add_del_qdisc(ifindex, false, 0, hook);
>  
> -    if (ovsthread_once_start(&block_once)) {
> +    if (ovsthread_once_start(&once)) {
>          probe_tc_block_support(ifindex);
>          /* Need to re-fetch block id as it depends on feature availability. */
>          block_id = get_block_id_from_netdev(netdev);
> -        ovsthread_once_done(&block_once);
> -    }
> -
> -    if (ovsthread_once_start(&multi_mask_once)) {

It might be good to have an empty line here to visually separate block-related
things from the 'mask' ones.

>          probe_multi_mask_per_prio(ifindex);
> -        ovsthread_once_done(&multi_mask_once);
> +        ovsthread_once_done(&once);
>      }
>  
>      error = tc_add_del_qdisc(ifindex, true, block_id, hook);
>