That's actually very helpful, since I was pretty sure there was a memory
problem but couldn't figure out where. I think there's a good chance this
will be an easy fix.

Gabe

On Wed, Dec 15, 2021, 8:59 AM Jason Lowe-Power <[email protected]> wrote:

> Ok, I was able to get a debugger to work and I dug in a bit more...
>
> The problem is that the new code does not initialize the __main__.py
> module. The original SST code had the following line:
> `pythonMain = PyImport_AddModule(PyCC("__main__"));`
>
> This was executed before `execPythonCommands`.
>
> In `execPythonCommands` we use the `pythonMain` variable. However, in the
> *new* code, that variable is NULL (or unitialized, actually).
>
> As far as I can tell, all of the new python changes didn't come with any
> documentation on how you are supposed to interact with Python from gem5.
> So, there's no good way for us to update this code.
>
> Gabe, if you can update the `execPythonCommands` function to work however
> you expected it to, that would be great.
>
> Thanks,
> Jason
>
> On Wed, Dec 15, 2021 at 10:45 AM Jason Lowe-Power <[email protected]>
> wrote:
>
>> Here's my understanding of where we are on this:
>>
>> As of
>> https://gem5.googlesource.com/public/gem5/+/cf7ce21848ea4aeee28737823e6e768f9a14ceaf
>> SST was working. (Committed Dec. 7th)
>>
>> Then, this large relation chain was pushed:
>> https://gem5-review.googlesource.com/c/public/gem5/+/49425 ending with
>> https://gem5.googlesource.com/public/gem5/+/4c1422e3ba780a5f152426e214b4be3d45b751e4.
>> This relation chain broke SST. This was committed on Dec. 8th.
>>
>> We have two options: Either we fix this bug ASAP (as in within 6 days so
>> we can release on 12/22) or we revert the changesets that were committed on
>> the 8th.
>>
>> SST is a *must have* feature of gem5 21.2. It is quite frustrating to see
>> it broken after all of the hard work that Hoa and Giacomo put into it.
>>
>> Let me know if I'm missing something.
>>
>> Thanks,
>> Jason
>>
>> On Sat, Dec 11, 2021 at 10:35 AM Gabe Black <[email protected]> wrote:
>>
>>> https://gem5-review.googlesource.com/c/public/gem5/+/54006
>>>
>>> At least one problem I ran into was that the order of static
>>> initializers was not determinstic, so the structures which said what
>>> embedded python modules existed might be statically constructed after the
>>> thing that consumes and sets them up. That could work by coincidence if the
>>> order is favorable, but it wasn't for me and so lots of things didn't exist
>>> as far as the python was concerned.
>>>
>>> To be clear, there is some mysterious deeper issue here which is
>>> probably separate from that. As far as I can tell running gem5 itself is
>>> working fine, but when running as a library in sst there is some sort of
>>> memory corruption or premature garbage collection or something, and it
>>> leads to a segfault or incorrect behavior (failure to import modules,
>>> failure to find things inside them, etc). Things were even more
>>> tempermental until I added what feels like an unnecessary increment of the
>>> reference count for the modules in the new pybind_init.hh, which seemed to
>>> tame things in gem5 proper at least. I'm too tired to keep looking for it
>>> right now, but hopefully this will give you a good leg up.
>>>
>>> Gabe
>>>
>>> On Sat, Dec 11, 2021 at 8:25 AM Jason Lowe-Power <[email protected]>
>>> wrote:
>>>
>>>> Everything was working as of last week-ish, if I remember correctly. We
>>>> were booting both Arm and RISCV full system with gem5 cores and SST
>>>> caches/memory.
>>>>
>>>> Cheers,
>>>> Jason
>>>>
>>>> On Sat, Dec 11, 2021, 8:23 AM Gabe Black <[email protected]> wrote:
>>>>
>>>>> Thanks, that was really helpful. I've fixed the compilation problems,
>>>>> and then a few more that were hiding behind that, including a few ones 
>>>>> that
>>>>> were intrinsic to the way sst was initializing the gem5 library (with
>>>>> dlopen). Was this working to begin with and all this breakage is new, or
>>>>> was it just that the compilation broke and there were these other problems
>>>>> already? I want to make sure I don't leave things in a worse state than
>>>>> when I got here, but I also don't want to go chasing down things that
>>>>> weren't working to begin with.
>>>>>
>>>>> I'm going to upload what I have so far, and hopefully someone else can
>>>>> take a look at it too. The current problem seems to be that the modules in
>>>>> _m5 aren't working right, either because they've been garbage collected, 
>>>>> or
>>>>> because they're not being set up properly, or...
>>>>>
>>>>> Gabe
>>>>>
>>>>> On Fri, Dec 10, 2021 at 8:17 PM Bobby Bruce <[email protected]>
>>>>> wrote:
>>>>>
>>>>>> Hey gabe.
>>>>>>
>>>>>> No idea if this is the _best_ solution to your problem, but my
>>>>>> solution would be to rebuild the image with this installed. Modify the
>>>>>> `util/dockerfiles/sst-11.1.0/Dockerfile` to the environment you want. 
>>>>>> Then
>>>>>> run `docker build -t <some name here> util/dockerfiles/sst-11.1.0` to 
>>>>>> build
>>>>>> an image with the name "<some name here>".
>>>>>>
>>>>>> Then you can execute `docker run -u $UID:$GID --volume $(pwd):$(pwd)
>>>>>> -w $(pwd) -it <same name here>` within the gem5 directory to spin up and
>>>>>> enter a container from the image you just built. I think you'll be able 
>>>>>> to
>>>>>> do what you want inside the container.
>>>>>>
>>>>>> Kind regards,
>>>>>> Bobby
>>>>>> --
>>>>>> Dr. Bobby R. Bruce
>>>>>> Room 3050,
>>>>>> Kemper Hall, UC Davis
>>>>>> Davis,
>>>>>> CA, 95616
>>>>>>
>>>>>> web: https://www.bobbybruce.net
>>>>>>
>>>>>>
>>>>>> On Fri, Dec 10, 2021 at 7:24 PM Gabe Black <[email protected]>
>>>>>> wrote:
>>>>>> >
>>>>>> > Dumb question: I'm trying to run gdb inside this container on the
>>>>>> sst thing. How do I do that? It's not installed in the container now, 
>>>>>> and I
>>>>>> can't (easily) figure out how to get it installed. I can tell docker to
>>>>>> install it, but then it seems to throw that away as soon as the command
>>>>>> ends.
>>>>>> >
>>>>>> > Gabe
>>>>>> >
>>>>>> > On Fri, Dec 10, 2021 at 5:09 PM Bobby Bruce <[email protected]>
>>>>>> wrote:
>>>>>> >>
>>>>>> >> Thanks Gabe,
>>>>>> >>
>>>>>> >> This is very much appreciated. I'm going to create the release
>>>>>> staging once a couple more things get in. Feel free to push any patches
>>>>>> related to these bugs to the release staging branch.
>>>>>> >>
>>>>>> >> If there is an order of priority I'd say the bug affecting SST is
>>>>>> of higher importance than that affecting the Weeklies (as far as I can 
>>>>>> see
>>>>>> the latter is hard to trigger). That being said, we'll apply both to the
>>>>>> new release one way or another.
>>>>>> >>
>>>>>> >> --
>>>>>> >> Dr. Bobby R. Bruce
>>>>>> >> Room 3050,
>>>>>> >> Kemper Hall, UC Davis
>>>>>> >> Davis,
>>>>>> >> CA, 95616
>>>>>> >>
>>>>>> >> web: https://www.bobbybruce.net
>>>>>> >>
>>>>>> >>
>>>>>> >> On Fri, Dec 10, 2021 at 5:02 PM Gabe Black <[email protected]>
>>>>>> wrote:
>>>>>> >>>
>>>>>> >>> Hi Bobby, not yet, I meant to look into this for the last couple
>>>>>> days but kept running out of time. I'm sitting down to work on it right 
>>>>>> now.
>>>>>> >>>
>>>>>> >>> Gabe
>>>>>> >>>
>>>>>> >>> On Fri, Dec 10, 2021 at 1:21 PM Bobby Bruce <[email protected]>
>>>>>> wrote:
>>>>>> >>>>
>>>>>> >>>> Hey Gabe,
>>>>>> >>>>
>>>>>> >>>> Is there any update on this?
>>>>>> >>>>
>>>>>> >>>> Kind regards,
>>>>>> >>>> Bobby
>>>>>> >>>> --
>>>>>> >>>> Dr. Bobby R. Bruce
>>>>>> >>>> Room 3050,
>>>>>> >>>> Kemper Hall, UC Davis
>>>>>> >>>> Davis,
>>>>>> >>>> CA, 95616
>>>>>> >>>>
>>>>>> >>>> web: https://www.bobbybruce.net
>>>>>> >>>>
>>>>>> >>>>
>>>>>> >>>> On Wed, Dec 8, 2021 at 5:51 PM Hoa Nguyen via gem5-dev <
>>>>>> [email protected]> wrote:
>>>>>> >>>>>
>>>>>> >>>>> Hi Gabe,
>>>>>> >>>>>
>>>>>> >>>>> I have more details about this. In this use case, SST
>>>>>> initialized the
>>>>>> >>>>> Python environment before adding the "gem5 object". This gem5
>>>>>> object
>>>>>> >>>>> will add more Python stuff from gem5 to the environment.
>>>>>> >>>>>
>>>>>> >>>>> The function that does that is initPython()
>>>>>> >>>>>
>>>>>> https://gem5.googlesource.com/public/gem5/+/refs/heads/develop/ext/sst/gem5.cc#415
>>>>>> >>>>>
>>>>>> >>>>> The following commands will pull the docker image for SST
>>>>>> testing
>>>>>> >>>>> purposes (note that host_gem5_root and guest_gem5_root must be
>>>>>> >>>>> specified),
>>>>>> >>>>>
>>>>>> >>>>> ```
>>>>>> >>>>> docker run -u $UID:$GID --volume
>>>>>> "${host_gem5_root}":"${guest_gem5_root}" -w \
>>>>>> >>>>>  "${guest_gem5_root}" --rm gcr.io/gem5-test/sst-env \
>>>>>> >>>>>  bash -c "\
>>>>>> >>>>> scons build/RISCV/libgem5_opt.so -j${nproc} --without-tcmalloc;
>>>>>> \
>>>>>> >>>>> cd ext/sst; \
>>>>>> >>>>> make clean; make; \
>>>>>> >>>>> sst --add-lib-path=./ sst/example.py;
>>>>>> >>>>> ```
>>>>>> >>>>>
>>>>>> >>>>> We appreciate your help!
>>>>>> >>>>>
>>>>>> >>>>> Regards,
>>>>>> >>>>> Hoa Nguyen
>>>>>> >>>>>
>>>>>> >>>>> On 12/8/21, Jason Lowe-Power <[email protected]> wrote:
>>>>>> >>>>> > Hey Gabe,
>>>>>> >>>>> >
>>>>>> >>>>> > This change breaks the SST integration. In the SST
>>>>>> integration python is
>>>>>> >>>>> > initialized from the SST module, not from init.cc (this is
>>>>>> because SST has
>>>>>> >>>>> > their own python interpreter).
>>>>>> >>>>> >
>>>>>> >>>>> > We would appreciate some help in fixing this. Hoa and Giacomo
>>>>>> can give you
>>>>>> >>>>> > an example that's breaking to help you fix it, I believe.
>>>>>> >>>>> >
>>>>>> >>>>> > https://gem5-review.googlesource.com/c/public/gem5/+/49413
>>>>>> >>>>> >
>>>>>> >>>>> > There's strong interest in having the SST integration working
>>>>>> in this
>>>>>> >>>>> > current release. We've spent a lot of time figuring out all
>>>>>> of the
>>>>>> >>>>> > intricacies and would appreciate any help you can provide in
>>>>>> these last few
>>>>>> >>>>> > days before the release!
>>>>>> >>>>> >
>>>>>> >>>>> > Thanks!
>>>>>> >>>>> >
>>>>>> >>>>> > Jason
>>>>>> >>>>> >
>>>>>> >>>>> _______________________________________________
>>>>>> >>>>> gem5-dev mailing list -- [email protected]
>>>>>> >>>>> To unsubscribe send an email to [email protected]
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>>>>>>
>>>>>
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