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| This page describes possible malloc (or PyMem_Malloc) replacements to be used for memory management in SAGE which is not directly controlled by Python as manual malloc calls, the GMP library etc. | This page describes possible malloc replacements to be used for memory management in SAGE which is not directly controlled by Python such as manual malloc/realloc calls, the GMP library etc.. == PyMem_Malloc == The Python memory manager does keep track of some previous allocated, unused, but not yet freed blocks so it should be faster than malloc itself. It is currently used in GMP and Pyrex code in SAGE. |
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| == default libCF Memory Manager == * GPL * seems to be faster for Integer addition than Python's manager {{{#!python sage: from sage.memory import * #only in my (malb) working copy |
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| == libCF old Memory Manager == * GPL * default memory manager for libCF * ZZ(3) + ZZ(5) with PyMem_Malloc: 8.21 microseconds, with the old libCF memory manager: 7.5 microseconds |
# PyMem_Malloc sage: x = 5; y = 3 sage: %timeit _ = x+y 100000 loops, best of 3: 8.15 microseconds per loop |
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| # default libCF memory manager sage: memman_malloc() sage: %timeit _ = x+y 100000 loops, best of 3: 7.36 microseconds per loop }}} |
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| * {{{Short description of the Givaro memory mechanism: each request of sz bytes returns the smallest bloc that contains at least sz bytes. Each bloc begins by a private data used to store size information or a pointer. All free blocs are linked in list. The allocation algorithm search in the corresponding list a free bloc, before call the system "malloc" routine. 512 different sizes of bloc are predefined. The maximum bloc size is 8054880 bytes. |
* Short description of the Givaro memory mechanism: each request of sz bytes returns the smallest bloc that contains at least sz bytes. Each bloc begins by a private data used to store size information or a pointer. All free blocs are linked in list. The allocation algorithm search in the corresponding list a free bloc, before call the system "malloc" routine. 512 different sizes of bloc are predefined. The maximum bloc size is 8054880 bytes. |
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| * Seems to be slower than PyMem_Malloc for Integer addition {{{#!python sage: from sage.memory import * sage: x = 5; y = 3 # PyMem_Malloc sage: %timeit _ = x+y 100000 loops, best of 3: 8.15 microseconds per loop # GivaroMM sage: givaro_malloc() sage: %timeit _ = x+y 100000 loops, best of 3: 8.36 microseconds per loop |
Malloc Replacements
This page describes possible malloc replacements to be used for memory management in SAGE which is not directly controlled by Python such as manual malloc/realloc calls, the GMP library etc..
PyMem_Malloc
The Python memory manager does keep track of some previous allocated, unused, but not yet freed blocks so it should be faster than malloc itself. It is currently used in GMP and Pyrex code in SAGE.
OMalloc
- currently non-free
- supposed to be very fast
- drop-in ?
DLMalloc
- LGPL
- used by OMalloc
- unsure what it does
default libCF Memory Manager
- GPL
- seems to be faster for Integer addition than Python's manager
1 sage: from sage.memory import * #only in my (malb) working copy
2
3 # PyMem_Malloc
4 sage: x = 5; y = 3
5 sage: %timeit _ = x+y
6 100000 loops, best of 3: 8.15 microseconds per loop
7
8 # default libCF memory manager
9 sage: memman_malloc()
10 sage: %timeit _ = x+y
11 100000 loops, best of 3: 7.36 microseconds per loop
libCF new Memory Manager
- GPL
crashed on me ([:MartinAlbrecht:malb]) when trying to use it from withing SAGE
GivMM
- GPL
- Short description of the Givaro memory mechanism: each request of sz bytes returns the smallest bloc that contains at least sz bytes. Each bloc begins by a private data used to store size information or a pointer. All free blocs are linked in list. The allocation algorithm search in the corresponding list a free bloc, before call the system "malloc" routine. 512 different sizes of bloc are predefined. The maximum bloc size is 8054880 bytes.
For higher bloc, the manager directly call malloc/free of the underlaying system.
Seems to be slower than PyMem_Malloc for Integer addition