[ofa-general] [infiniband-diags] add --loop_ports option to perfquery

[Hal Rosenstock]

Hi again Al,

On Wed, Oct 8, 2008 at 6:45 PM, Al Chu <chu11 at llnl.gov> wrote:
> Hey Hal,
>
> On Wed, 2008-10-08 at 09:44 -0400, Hal Rosenstock wrote:
>> Hi Al,
>>
>> On Wed, Oct 8, 2008 at 6:26 AM, Al Chu <chu11 at llnl.gov> wrote:
>> > Hey Hal,
>> >
>> > On Wed, 2008-10-08 at 07:03 -0400, Hal Rosenstock wrote:
>> >> Al,
>> >>
>> >> On Tue, Oct 7, 2008 at 6:54 PM, Al Chu <chu11 at llnl.gov> wrote:
>> >> > Hey Sasha,
>> >> >
>> >> > We have a switch here that does not report the AllPortSelect flag as a
>> >> > capability.  It's pretty annoying typing each port on the switch or
>> >> > always having to script around this one oddball switch we have.  So I
>> >> > added an option --loop_ports for perfquery.  If you want to do something
>> >> > to all the ports on the CA/Switch, but AllPortSelect isn't available, it
>> >> > loops through all the available ports instead.
>> >>
>> >> Why not add simulated AllPortSelect for multiple ports rather than add
>> >> another perquery option for this ?
>> >
>> > I did try that, and it did seem to work for the switches we had.  But
>> > when I read the IB spec, it said something to the affect that if a
>> > system doesn't support AllPortSelect, setting the PortSelect field to
>> > 0xFF was undefined behavior.
>>
>> I was suggesting that the emulation support (when AllPortSelect is not
>> supported) be enhanced for multiple ports and work on both CAs and all
>> switches. The one difference is one response for AllPortSelect
>> (whether emulated or not) v. many responses for port loop.
>
> Oh.  I thought you were referring the the workaround "simulation" that
> was in the original code.  But you're referring to aggregating the
> data/output make it look like AllPortSelect was supported.  I'll put
> this on the TODO.

So it seems that the reason for adding an additional option for this
is that the lack of this support ? Are there any other uses ?

-- Hal

>>
>> >> > There was already a workaround in the tool for a CA that did not support
>> >> > the AllPortSelect flag.  I get the feeling the workaround may have been
>> >> > for a specific hardware, so I kept the workaround in there.
>> >>
>> >> > Al
>> >> >
>> >> > --
>> >> > Albert Chu
>> >> > chu11 at llnl.gov
>> >> > Computer Scientist
>> >> > High Performance Systems Division
>> >> > Lawrence Livermore National Laboratory
>> >> >
>> >> > _______________________________________________
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>> >> > general at lists.openfabrics.org
>> >> > http://  lists.openfabrics.org/cgi-bin/mailman/listinfo/general
>> >> >
>> >> > To unsubscribe, please visit http://  openib.org/mailman/listinfo/openib-general
>> >> >
>> >>
>> >> There are also 2 for loops which are not correct for some switches:
>> >> for (i = 1; i <= num_ports; i++)
>> >
>> > I guess I've never seen a switch that doesn't go from 1 to num_ports.
>> > Is there something else I need to handle?
>>
>> Yes, per the spec, enhanced SP0 supports PortCounters. All your
>> switches likely support AllPortSelect so it's not an issue there.
>
> Ok I see now.  Wasn't aware of it.  I'll get a patch together.
>
> Thanks,
> Al
>
>> -- Hal
>>
>> > Al
>> >
>> >> -- Hal
>> >>
>> > --
>> > Albert Chu
>> > chu11 at llnl.gov
>> > Computer Scientist
>> > High Performance Systems Division
>> > Lawrence Livermore National Laboratory
>> >
>> >
>>
> --
> Albert Chu
> chu11 at llnl.gov
> Computer Scientist
> High Performance Systems Division
> Lawrence Livermore National Laboratory
>
>