[ofa-general] [PATCH 5/7 V3] osm: QoS - adding QoS policy options

[Hal Rosenstock]

On 8/30/07, Sasha Khapyorsky <sashak at voltaire.com> wrote:
> On 04:19 Thu 30 Aug     , Yevgeny Kliteynik wrote:
> >  Sasha Khapyorsky wrote:
> > > On 19:12 Wed 29 Aug     , Hal Rosenstock wrote:
> > >> On 8/29/07, Sasha Khapyorsky <sashak at voltaire.com> wrote:
> > >>> On 17:48 Wed 29 Aug     , Hal Rosenstock wrote:
> > >>>>> OK, there are three ways we want this thing to work:
> > >>>>> 1. QoS is off
> > >>>>> 2. The old QoS is on but w/o policy file
> > >>>>> 3. The old QoS is on, plus reading policy file
> > >>>>>
> > >>>>> The first option is clear: if a user doesn't turns QoS on (-Q), QoS is
> > >>>>> off as before.
> > >>>>>
> > >>>>> Second and third options: if QoS is on, OpenSM looks for policy file in
> > >>>>> the default
> > >>>>> location or in other location that was provided by user. If the file is
> > >>>>> not found,
> > >>>>> QoS works as before.
> > >>>> This sounds OK to me and is my first preference.
> > >>>>
> > >>>>> Do we want to add additional option for "enhanced" QoS?
> > >>>>> If so, we will have three QoS-ralated command line options:
> > >>>>>  - option for turning the QoS on (currently -Q)
> > >>>>>  - option to turn the new QoS on (some new letter - must get
> > >>>>>    one quick before they all run out... :)
> > >>>>>  - option for policy file location if differs from default (currently
> > >>>>> -Y)
> > >>>> This seems like the least preferable to me. Also, would need to deal
> > >>>> with both on which seems to mean use new QoS.
> > >>>>
> > >>>>> Alternatively, we can turn -Q option into levels:
> > >>>>>  -Q 0: QoS is off (default)
> > >>>>>  -Q 1: old QoS is on
> > >>>>>  -Q 2: old QoS plus reading policy file
> > >>>> This one also seems OK to me (second preference).
> > >>>>
> > >>>> Anyone else with an opinion on this ? Sasha ?
> > >>> I like -Q and -Y as Yevgeny proposed.
> > >> So is that the first option ?
> > > Yes. It is simplest and provides the same functionality.
> >
> >  This is what's implemented right now
> >
> > >> Actually, I think I like the third option best now that I think more
> > >> on this. It seems a little odd to me to rely on the policy file not
> > >> being present to determine which QoS to run. Seems a little cleaner
> > >> this way to me.
> > > We need file name option anyway, so things like '-Q 1 -Y ...' are
> > > unclear. Also it would be nice to have "universal" (not for "two QoS")
> > > user interface in order to not change it later.
> >
> >  I would say that -Q and -Y are enough, but it poses some questions:
> >  Do we want to allow the case when a user has policy file in a default
> >  location, but he wants OpenSM to ignore this file and still have QoS on?
>
> -Y '' should be fine then.
>
> >  In case of partitions file we don't have an option to ignore partition
> >  config file in a default location.
> >
> >  And if OpenSM ignores policy file, what would it mean?
> >  Would it be the "old" QoS?
>
> Yes. Is there another useful options?
>
> >  And when the setup part of the new QoS will be ready, would we still want
> >  the SL2VL and VLArb tables to appear in the opts file?
>
> Don't think. Why we need it in two places?

Are you saying that the existing QoS will get these tables from the
new QoS syntax (and the existing syntax eliminated) ? If so, what
about backward compatibility ? Also, how straightforward is it to
specify the equivalent as the existing syntax ? Will a conversion tool
be supplied ?

-- Hal

> Sasha
>