I needed to make some changes to list-attr.sm recently and realized that
it probably should really be redone now that we have parallel nested
machines available. listattr is a server operation that retrieves
attributes for a list of handles at once. The old version duplicated
logic from get-attr.sm, while the new version does a pjmp to the nested
pvfs2_get_attr_work_sm machine instead.
There are a few advantages to this approach:
- it gives us a complete example of pjmp in trunk
- we don't have to keep listattr code in sync with getattr, since they
now share the same core logic (listattr was already a little behind)
- the list-attr.sm source code is much smaller now
- list-attr.sm should be faster now as well, because it is capable of
getting many trove operations queued up at once rather than iterating
through each of the getattr's (and waiting for completion of each) in serial
I could stand some extra eyes to look at list-attr.sm and make sure the
implementation in trunk is sane. Here is a link if anyone wants to look
at it online:
http://www.pvfs.org/fisheye/browse/~raw,r=1.9/PVFS/src/server/list-attr.sm
There are two goofy bits of code marked with a "TODO" comment:
- Running pvfs2_get_attr_work_sm requires setting a variety of
undocumented parameters before launching it. I'm not sure how to best
clean this up (or if I should just let this slide for now).
- After the pjmp, it is a little hard to find the parent frame (which is
useful to have before popping the other frames so that you have
somewhere to store results). I ended up just iterating through the
frames looking for it, but I would like to find a nicer way to do this too.
-Phil
_______________________________________________
Pvfs2-developers mailing list
[email protected]
http://www.beowulf-underground.org/mailman/listinfo/pvfs2-developers
