[ovs-dev] [PATCH] dpif-netdev: Update comment about flow installation race.

Gregory Rose gvrose8192 at gmail.com
Wed Apr 17 15:57:42 UTC 2019


On 4/17/2019 1:43 AM, Ilya Maximets wrote:
> Userspace datapath uses per-PMD flow tables/classifiers for a long
> time. However, it was decided to keep this race window to not block
> revalidators. Comment should be updated to reflect the current state.
>
> Fixes: 1c1e46ed8457 ("dpif-netdev: Add per-pmd flow-table/classifier.")
> Signed-off-by: Ilya Maximets <i.maximets at samsung.com>
> ---
>   lib/dpif-netdev.c | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
> index bd9718824..645981c38 100644
> --- a/lib/dpif-netdev.c
> +++ b/lib/dpif-netdev.c
> @@ -6535,8 +6535,7 @@ handle_packet_upcall(struct dp_netdev_pmd_thread *pmd,
>            * could have already been installed since we last did the flow
>            * lookup before upcall.  This could be solved by moving the
>            * mutex lock outside the loop, but that's an awful long time
> -         * to be locking everyone out of making flow installs.  If we
> -         * move to a per-core classifier, it would be reasonable. */
> +         * to be locking revalidators out of making flow modifications. */
>           ovs_mutex_lock(&pmd->flow_mutex);
>           netdev_flow = dp_netdev_pmd_lookup_flow(pmd, key, NULL);
>           if (OVS_LIKELY(!netdev_flow)) {

LGTM
Reviewed-by: Greg Rose <gvrose8192 at gmail.com>



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