24/06/2020 11:56, Bruce Richardson: > On Wed, Jun 24, 2020 at 11:23:55AM +0200, David Marchand wrote: > > On Tue, Jun 23, 2020 at 3:16 PM Ananyev, Konstantin > > <konstantin.anan...@intel.com> wrote: > > > > Even before this series, MP has no protection on lcore placing between > > > > primary and secondary processes. > > > > > > Agree, it is not a new problem, it has been there for a while. > > > Though making lcore assignment dynamic will make it more noticeable and > > > harder to avoid. > > > With static only lcore distribution it is much easier to control things. > > > > > > > Personally, I have no use for DPDK MP and marking MP as not supporting > > > > this new feature is tempting for a first phase. > > > > If this is a strong requirement, I can look at it in a second phase. > > > > What do you think? > > > > > > In theory it is possible to mark this new API as not supported for MP. > > > At least for now. Though I think it is sort of temporal solution. > > > AFAIK, MP is used by customers, so sooner or later someone will hit that > > > problem. > > > > I understand this argument. > > But then we don't see those customers giving feedback. > > > > > > > Let say, we do have pdump app/library in our mainline. > > > As I can see - it will be affected when users will start using this new > > > dynamic lcore API > > > inside their apps. > > > > Supporting lcore allocation in MP requires exchanges between > > primary/secondary processes like what we have for memory allocations. > > It will be quite a beast to get to work fine, while not even knowing > > if people actually want to use both. > > > > For v4, I added a check to exclude MP and the new API. > > I am still willing to help if people do care about using both features > > together. > > I wonder how much we could simplify DPDK generally if we had to enable a > specific runtime flag to enable multi-process support and it was off by > default. This would break proc_info I think, but maybe we could provide > telemetry callbacks to provide the same data, but beyond that it would just > allow us to know whether a DPDK app is actually using MP, or just running > as a single process.
Same thought here. I like the idea of a "mode flag" when multi-process is in use. Should it be an user explicit flag or an automatic one?
