Re: [dpdk-dev] rte_hash thread safe

[Jim Murphy <jmurphy@arista.com>]

Right, the threads using the DPDK libraries must do the right RCU stuff,
declare quiescent, etc.

I mentioned hooks to address the licensing issue. So for places in rte_hash
were synchronization must be done a no-op function could be called but
users could replace that function with one of their choosing.

Thanks,

Jim




On Mon, Apr 23, 2018 at 6:14 PM, Stephen Hemminger <
stephen@networkplumber.org> wrote:

> On Mon, 23 Apr 2018 17:48:50 -0700
> Jim Murphy <jmurphy@arista.com> wrote:
>
> > Anecdotally I've heard that the urcu hash implementation is slower than
> > rte_hash based on pure lookup performance. Has anyone considered adding
> RCU
> > hooks into rte_hash?
>
>
> Not really possible with DPDK (as I said earlier) because DPDK does not
> have concept
> of thread quiescent period to allow for safe deletion.  You could manually
> use RCU
> concepts of RCU and RTE hash; it would require using userspace RCU
> primitives
> inside DPDK.  This would cause a dependency that would prevent that from
> ever
> being merged upstream due to license conflict; but since DPDK is liberal
> BSD
> license you are free to do it and maintain it on your own.
>