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

[Al Chu]

Hey Hal,

On Thu, 2008-10-09 at 08:37 -0400, Hal Rosenstock wrote:
> 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 ?

I made the --loop_ports option b/c I just didn't want to change the
default behavior perfquery.  But we could easily make it an automatic if
the AllPortsSelect flag isn't supported.

Thinking about it, there is a bit of a subtlety in the command line
options and expectations.

If a user inputs a port of '255', to me this means that the user wants
to do an AllPortSelect and we should error out if AllPortSelect isn't
supported.

If a user inputs the '-a' option, it suggests that they want perfquery
to operate on every port, suggesting that we could automatically loop if
they don't input --loop_ports.

Al

> -- 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
> >> >> >
> >> >> > _______________________________________________
> >> >> > general mailing list
> >> >> > 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
> >
> >
> 
-- 
Albert Chu
chu11 at llnl.gov
Computer Scientist
High Performance Systems Division
Lawrence Livermore National Laboratory