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

[Yevgeny Kliteynik]

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?

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?

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?

-- Yevgeny

> Sasha
>