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

[Olivier Matz <olivier.matz@6wind.com>]

Hi Tonghao,

On Mon, Mar 16, 2020 at 03:43:40PM +0800, Tonghao Zhang wrote:
> On Mon, Mar 9, 2020 at 9:15 PM David Marchand <david.marchand@redhat.com> wrote:
> >
> > 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.
> Hi Olivier
> any progress？will apply this patch or wait your patch?

Sorry if it wasn't clear, but my proposition was just an idea, I have no
time yet to work on it. Feel free to implement it by yourself, and I'll
help to review the patches.

Thanks,
Olivier