Opened 8 months ago
Last modified 11 days ago
#26349 needs_work defect
Memory leaks with matrix multiplication over GF(2)
Reported by: | gh-antoine06 | Owned by: | |
---|---|---|---|
Priority: | major | Milestone: | sage-8.8 |
Component: | linear algebra | Keywords: | memory leaks |
Cc: | Merged in: | ||
Authors: | Reviewers: | Travis Scrimshaw | |
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description (last modified by )
As reported on this ask question:
n = 8 X = zero_vector(GF(2), n) M = zero_matrix(GF(2), n, n) for _ in range(10000000): Y = M * X
leads to:
m4ri_mm_malloc: malloc returned NULL --------------------------------------------------------------------------- RuntimeError Traceback (most recent call last) <ipython-input-1-04da27075a1c> in <module>() 4 5 for _ in range(Integer(10000000)): ----> 6 Y = M * X 7 /opt/sagemath/sage-source/local/lib/python2.7/site-packages/sage/structure/element.pyx in sage.structure.element.Matrix.__mul__ (build/cythonized/sage/structure/element.c:23537)() 3666 return (<Matrix>left)._matrix_times_matrix_(<Matrix>right) 3667 if BOTH_ARE_ELEMENT(cl): -> 3668 return coercion_model.bin_op(left, right, mul) 3669 3670 cdef long value /opt/sagemath/sage-source/local/lib/python2.7/site-packages/sage/structure/coerce.pyx in sage.structure.coerce.CoercionModel_cache_maps.bin_op (build/cythonized/sage/structure/coerce.c:9757)() 1173 action = self.get_action(xp, yp, op, x, y) 1174 if action is not None: -> 1175 return (<Action>action)._call_(x, y) 1176 1177 try: /opt/sagemath/sage-source/local/lib/python2.7/site-packages/sage/matrix/action.pyx in sage.matrix.action.MatrixVectorAction._call_ (build/cythonized/sage/matrix/action.c:5997)() 325 else: 326 v = v.dense_vector() --> 327 return A._matrix_times_vector_(v) 328 329 /opt/sagemath/sage-source/local/lib/python2.7/site-packages/sage/matrix/matrix_mod2_dense.pyx in sage.matrix.matrix_mod2_dense.Matrix_mod2_dense._matrix_times_vector_ (build/cythonized/sage/matrix/matrix_mod2_dense.c:6487)() 573 return VS.zero() 574 cdef Vector_mod2_dense c = Vector_mod2_dense.__new__(Vector_mod2_dense) --> 575 sig_str("matrix allocation failed") 576 c._init(self._nrows, VS) 577 c._entries = mzd_init(1, self._nrows) RuntimeError: matrix allocation failed
Change History (5)
comment:1 Changed 8 months ago by
- Description modified (diff)
comment:2 Changed 8 months ago by
comment:3 Changed 2 weeks ago by
- Milestone changed from sage-8.4 to sage-duplicate/invalid/wontfix
- Status changed from new to needs_review
Tested this on Sage 8.7, macOS Mojave and Ubuntu 19.04, and the problem seems to be fixed.
If someone else could confirm this on another OS (the person on ask used debian buster) then we can probably close this as wontfix.
comment:4 Changed 2 weeks ago by
- Reviewers set to Travis Scrimshaw
- Status changed from needs_review to positive_review
Confirmed on Ubuntu 16.04 that I am not seeing a leak.
comment:5 Changed 11 days ago by
- Milestone changed from sage-duplicate/invalid/wontfix to sage-8.8
- Status changed from positive_review to needs_work
I'm still seeing suspicious behaviour on sage 8.8.beta3 / python3, on Fedora:
If I set a vmem limit of 10 gigabyte and execute
n = 1000 X = zero_vector(GF(2), n) M = zero_matrix(GF(2), n, n) for _ in range(10000000): Y = M + M
sage still crashes for me (whereas a small number of iterations does run without problem).
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It would seem the memory management on these objects is rather fundamentally broken. Also with lines like
Y= M+M
orY=X+X
I am seeing similar leaking behaviour.