Ticket #9265 (closed: fixed)
Memory leak with Python fit functions
| Reported by: | Martyn Gigg | Owned by: | Martyn Gigg |
|---|---|---|---|
| Priority: | major | Milestone: | Release 3.2 |
| Component: | Python | Keywords: | |
| Cc: | Blocked By: | ||
| Blocking: | Tester: | Arturs Bekasovs |
Description
From James Lord, ISIS:
I've found that a Python fit function can leak LOTS of memory, especially if used for repetitive fits in a script. Try the attached example which uses either ExpDecayOsc (built-in) or my Python equivalent version. Give names for the 2 output workspaces and choose the Python or built in function. It does 20 fits to a 5000 point data set and it'll leak 300-500 Mbytes! The actual fit results are correct and there's no detectable leak with the built in fit function.
Attachments
Change History
comment:3 Changed 6 years ago by Martyn Gigg
Fix memory leak in python fit functions.
The result returned from the function1D/functionLocal call needs to have its reference count decremented as the returned array is a new numpy array. Refs #9265
Changeset: fa24a168004122b77305706395cef61404617a7d
comment:4 Changed 6 years ago by Martyn Gigg
- Status changed from inprogress to verify
- Resolution set to fixed
Branch: bugfix/9265_python_function_memleak
Tester: The attached python algorithm demonstrates the bug. Before starting testing run the check that you see a memory leak:
- open a system monitor that allows you to monitor memory usage of the MantidPlot process
- start MantidPlot & note the amount of memory used
- run the attached script to register the new algorithm LeakyFit and start this from the algorithms box
- enter two workspace names & tick the UsePythonFunc box & click run
- after the algorithm completes go to File->Clear All Memory
Look at the memory usage, it should still be over 500Mb.
Merge the branch, build the code & then run the steps above again and you should see the memory return to the same level as when MantidPlot started.
comment:5 Changed 6 years ago by Arturs Bekasovs
- Status changed from verify to verifying
- Tester set to Arturs Bekasovs
comment:6 Changed 6 years ago by Arturs Bekasovs
Reproduced the bug on current stable version. Is leaking only with "UsePythonFunc".
Code changes make sense: PyObject-s reference counts stay correct now, which makes them to be released when the time comes.
The problem appear to be solved with the changes merged. Memory usage is stable at <100mb throughout the fit, with both "UsePythonFunc" enabled and disabled.
comment:7 Changed 6 years ago by Arturs Bekasovs
- Status changed from verifying to closed
Merge remote-tracking branch 'origin/bugfix/9265_python_function_memleak'
Full changeset: f573dd385a236728cebdf7f7989594685c95bed5
