Re: [dpdk-dev] [PATCH dpdk-dev v3] mempool: sort the rte_mempool_ops by name

[David Marchand <david.marchand@redhat.com>]

On Mon, Mar 9, 2020 at 9:56 AM Tonghao Zhang <xiangxia.m.yue@gmail.com> wrote:
> On Mon, Mar 9, 2020 at 4:27 PM Olivier Matz <olivier.matz@6wind.com> wrote:
> > The fact that the ops index changes during mempool driver lifetime is
> > indeed frightening, especially knowning that this is a dynamic
> > registration that could happen at any moment in the life of the
> > application. Also, breaking the ABI is not desirable.
> That solution is better.
>
> > Let me try to propose something else to solve your issue:
> >
> > 1/ At init, the primary process allocates a struct in shared memory
> >    (named memzone):
> >
> >    struct rte_mempool_shared_ops {
> >      size_t num_mempool_ops;
> >      struct {
> >        char name[RTE_MEMPOOL_OPS_NAMESIZE];
> >      } mempool_ops[RTE_MEMPOOL_MAX_OPS_IDX];
> >      char *mempool_ops_name[RTE_MEMPOOL_MAX_OPS_IDX];
> >      rte_spinlock_t mempool;
> >    }
> >
> > 2/ When we register a mempool ops, we first get a name and id from the
> >    shared struct: with the lock held, lookup for the registered name and
> >    return its index, else get the last id and copy the name in the struct.
> >
> > 3/ Then do as before (in the per-process global table), except that we
> >    reuse the registered id.
> >
> > We can remove the num_ops field from rte_mempool_ops_table.
> >
> > Thoughts?

It seems better, just adding Anatoly and Bruce who know more about multiprocess.

Tonghao, could you add a unit test to exhibit the issue as part of this work?

Thanks.


-- 
David Marchand