> -----Original Message----- > From: Burakov, Anatoly > > On 26-Jul-19 4:56 PM, Lipiec, Herakliusz wrote: > > > > > >> From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of Burakov, Anatoly > >> On 26-Jul-19 4:01 PM, Stephen Hemminger wrote: > >>> On Fri, 26 Jul 2019 10:53:58 +0100 > >>> "Burakov, Anatoly" <anatoly.bura...@intel.com> wrote: > >>> > >>>>> > >>>>> NP to disallow it. > >>>>> In fact, I think it would be easier for everyone just to drop > >>>>> current DPDK MP model, and keep just standalone DPDK instances. > >>>> > >>>> That's the dream, but i don't think it'll ever come to fruition, at > >>>> least not without a huge push from the community. > >>> > >>> There are several net appliances that require primary/secondary model. > >>> I think initially during DPDK development it was sold as a feature > >>> to the Network vendors. > >>> > >>> It might be possible to clamp down on what API's are supported by > >>> secondary process. For example, disallowing any control operations > >>> start/stop > >> etc. > >>> > >> > >> We're getting slightly off topic here. > >> > >> The original question was about whether we want to support a use case > >> where a secondary can initialize after primary process has died, and > >> if we don't, whether we want to 1) outright deny initialization, or > >> 2) allow it, but document as unsupported and discourage it. > > Allowing something that is unsupported sounds like asking for trouble. > > We wouldn't be "allowing" it as much as we'd just be disclaiming any > responsibility for when things go wrong, *if* someone tries that. I suppose > the > concern is that someone would try that /accidentally/, and possibly screw up > other secondary processes that may still be running. > > > > >> > >> The only use case i can think of that would require it is proc-info app. > >> Dumping stuff from a dead process can be useful for debugging, so perhaps > we > >> can agree to put a warning at EAL startup, saying that this is not > >> supported, > but > >> still allow processes to initialize. > >> > > If this is supposed to be useful for debugging then maybe allow only when > some kind of flag is passed to eal? > > This would also prevent from initializing the process incidentally. > > We have too many EAL flags as it is! I suppose this could be done - > proc-info already hardcodes the "--proc-type" flag so that it only ever > runs as a secondary, we could add another one there. So, technically, > this is doable. Well it’s a bad idea to allow this without any "yes I know what I'm doing"
> > I'm just not sure of the prospect of adding a yet another EAL flag to > serve a purpose of enabling one specific application to run. That said, > an "--i-know-what-i-am-doing" flag certainly sounds like a fun idea! Well are there any other "unsupported" operations in dpdk ? Maybe one "--i-(don’t)-know-what-i-am-doing" aka debug (devmode, dangerous or whatever) flag is a good option to enable/disable these kind of behaviours and cover them all, this would definitely help preventing someone from doing this accidentally, or unknowingly (for example from within a script). > > -- > Thanks, > Anatoly
