Ok. I have fixed that "only zero indexes work" issue in trunk too in order to be able to index 0..N, but I didn't do anything beyond that with it. If you have a patch with your sm code changes that we can go ahead and push to trunk that would be great.

You might want to go ahead and consider merging some of these other recent changes to trunk into your branch as well. Some things here from about the 11th of this month and newer might be relevant for what you are working on. There are some generic fixes to sm / pjmp functionality, and also some cleanup of getattr_work that makes it a little safer to call from other parents:

http://www.pvfs.org/fisheye/changelog/~br=MAIN,author=pcarns/PVFS

So would a -1 index get you the very outermost parent (ie, the bottom of the stack)? In the more general case it may still be helpful to just get to the level right before pjmp rather than all the way to the bottom, particularly if the pjmp is issued from a nested machine.

-Phil

walt wrote:
Phil, I'll look at the code when I can. I'm interested in the get_attr_work issue, we are calling that in the create_file request, and we have also created a set_attr_work SM and will likely be setting up some others in our work. At minimum we need to document the parameters in the code. Whatever gets done here we will probably want to make sure it gets replicated in the trunk as well as our branch.

Also, in our branch I have modified the parallel state machine code a little to fix the problem you mentioned wrt getting the parent frame. In the version we checked out of trunk, only a zero index could be specified - otherwise an infinite loop resulted. Also, it seemed to assume a positive index. I modified it to allow both positive and negative indexes, so a -1 index would give you the parent frame, and 0..N gives the frames on top of the stack (which is actually circular).

Pretty simple mod actually, I can try to create a patch for it and you can try it out.

Keep me up to date on that other issue.

Walt

Phil Carns wrote:
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
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