Introduction

Sage 2.8.5 and later supports a number of valgrind tools:

memcheck: memory leak detector
massif: heap and stack profiler
cachegrind: cache profiler, i.e. L1 & L2 hit and misses
callgrind: general profiler

Valgrinding Sage is difficult because it runs on top of Python which poses a number of challenges compared to pure C/C++ code. Run

sage -optional

to see the list of optional packages. You should install the valgrind.spkg with the highest revision number.

Valgrind Version

The latest official valgrind 3.2.3 does not work. You need to build from 3.3.0svn trunk. There is an experimental Sage valgrind.spkg that works and is used by many of the Sage developers.

Known Issues With Sage Components

GAP cannot be valgrinded. It isn't due to the use of sbrk, but GAP somehow fails to extend its own workspace when run under valgrind
libpari makes valgrind terminate itself when it expands its own allocated heap. There is no known workaround at this time. You should see an error message like:

valgrind: m_mallocfree.c:209 (get_bszB_as_is): Assertion 'bszB_lo == bszB_hi' failed.
valgrind: Heap block lo/hi size mismatch: lo = 100000048, hi = 280100984.
Probably caused by overrunning/underrunning a heap block's bounds.

Preliminary Presentation

More to come at SD6. But: [attachment:SageDays5_preliminary_valgrind_talk.pdf]

Interesting Experimnetal Valgrind Tools/Components

client requests: see http://valgrind.org/docs/manual/mc-manual.html#mc-manual.clientreqs
omega: Is getting integrate as experimental tool into 3.3.0svn
chronicle-recorder: Uses a patched 3.2.3 release - see http://code.google.com/p/chronicle-recorder/ - for a python interface see http://www.visophyte.org/blog/2007/07/26/chroniquery-chronicle-recorder-and-python-boogie-down/

ToDo