On 09:34 Thu 16 Apr     , Hal Rosenstock wrote:
> >
> > Yes, and you can use lid value as such flag - just simpler.
> 
> When GID redirection is specified by client, LID must be 0 so I don't see 
> this.

1. GID redirection is not implemented in this patch.
2. In any case you will need to resolve LID value (using GID) in order
to send MAD.

So LID = 0 can be used as invalid redirection data flag. But this was
a minor comment.

> > My point was different - to separate redirection related data from main
> > flow.
> 
> I'm still not sure what you mean by this. Encapsulate the redirection
> data better so it is obtained by some potentially common routine ?

Yes. And also to not use "fake" redirection fields (specifically pkey_ix)
in non-redirected flow - this is why I think you need 'port' structure.

> >> > PerfMgr is always running over discovered fabric so maybe local port
> >> > number should be detected later at start of PerfMgr process cycle just
> >> > using OpenSM DB.
> >>
> >> Why is that better than doing this at bind time of PerfMgr ?
> >
> > At least two reasons: faster and less code.
> 
> Are you sure the OpenSM DB accesses will be faster than the vendor calls here 
> ?

Yes, it is direct memory read against opening and parsing many files
(+ memory allocations, etc.).

> Is bind performance sensitive anyhow ?

Not at all, but all what you need here is just local port number - and 40
(or so) lines of the code (which is 80% duplicated with pkey validation)
for doing this looks like overkill for me (not in sense of performance).

> The performance comment is
> clearly relevant to the main flow though.

Sure, but there you just need to read a value.

> >> > Also what about letting "chance" for port to refresh redirection info?
> >>
> >> What do you mean ?
> >
> > When port has invalid redirection data, should you care about attempting
> > to refresh this?
> 
> If the PMA gives bad redirection data (which BTW is noncompliant), it
> seems likely to do this again so I'm not sure about the value of this.
> Do you think that's a better thing to do ?

I don't have a clear opinion (and so asked). Actually if I understood
your code correctly this means that if some port once gets bad
redirection data it will dropped from PerfMgr cycle forever, right?

> >> Redirection does not occur frequently.
> >
> > How could we know:)
> 
> It's the current use case for PerfMgt.

Let's suppose it happens just three times per one PerfMgr cycle -
3 > 1 anyway.

Another important advantage is that in case when pkey tables are
prepared *before* actual PerfMgr cycle and will not slow down querying
itself.

Another thought - could p_physp->pkeys be used for index
detection/validation?

> > When OpenSM is in master mode it cannot change (PerfMgr is synchronized
> > with heavy sweep).
> >
> > It is possible with standby OpenSM, so what - this single request will
> > fail once.
> 
> Some recovery for such failure would be needed.

Not really - next PerfMgr cycle will fetch valid data.

> Also, what about not active ?

Same as standby (let's call it "non-master" modes).

> >> > All above are not OpenSM errors, but wrong external data. I think it
> >> > should be logged as VERBOSE messages.
> >>
> >> I agree it's wrong external data but it seems serious enough to me to
> >> treat as an error.
> >
> > And some stupid port will be able to put OpenSM in endless error
> > printing. I don't think it is a good idea.
> 
> It would be a non compliant PMA which I would think we'd want to know
> about sooner rather than later.

If an admin want to care about this (and also about other such sort of
things) he/she will turn verbosity "on".

> >> Seems like some sort of configuration error to me if this is disabled
> >> at the manager but the PMA wants to use it.
> >
> > PMA shouldn't dictate here.
> 
> PMA does dictate redirection. Manager has no way to shut it off.

But it should be able to ignore this (including "noisy" logging).

> If
> manager turns off it's handling of redirection, then it just doesn't
> work (that port is inaccessible by the manager). This argues for the
> default to be enabled. The current default is disabled since this code
> was deemed experimental.

Right, and it should be consistent with this (now default) setting.

> >> > BTW, why to bother with verifying redirection info when redirection
> >> > support is disabled anyway?
> >>
> >> I thought it was useful to know the redirection info was invalid
> >> rather than getting the disabled notification and then enabling and
> >> finding out.
> >
> > For PMAs debug purposes redirection support should be switched "on"
> > obviously.
> 
> Why do you say debug purposes ? Isn't it any purpose ?

I meant PMA support + PMA debug.

Sasha
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