Yes, you can use valgrind with Python. You just need to use the valgrind suppression file provided by the Python developers, so you don’t get a bunch of false positives due to Python’s custom memory allocation/reallocation functions. The valgrind suppression file can be found here: http://svn.python.org/projects/python/trunk/Misc/valgrind-python.supp IMPORTANT: You need to uncomment the lines for PyObject_Free … Read more
For machine instruction profiling use valgrind’s callgrind (also, cachegrind can do cache and branch prediction profiling which is quite nice). For time measurements use google’s cpu profiler, it gives way better results than gprof. You can set sampling frequency and it can show the output as a nice annotated call graph.
Yes, I recommend to treat possibly lost as severe as definitely lost. In other words, fix your code until there are no losts at all. Possibly lost can happen when you traverse an array using the same pointer that is holding it. You know that you can reset the pointer by subtracting the index. But … Read more
On 2013-11-01, the valgrind team announced Valgrind 3.9.0: We are pleased to announce a new release of Valgrind, version 3.9.0, available from http://www.valgrind.org. 3.9.0 is a feature release with many improvements and the usual collection of bug fixes. This release adds support for MIPS64/Linux, Intel AVX2 instructions and POWER8 instructions. DFP support has been added … Read more
Valgrind follows forked processes when given the –trace-children=yes option. You should be able to achieve this by using suitable filters. No. Valgrind hooks into the module loading code using LD_PRELOAD, so attaching to a running process is not possible.
Use return 0; instead of exit(0); at the end of main. The use of exit circumvents the execution of the destructors.
The following minimal test case exhibits the behaviour you describe: #include <pthread.h> #include <unistd.h> void *app1(void *x) { sleep(1); pthread_exit(0); } int main() { pthread_t t1; pthread_create(&t1, NULL, app1, NULL); pthread_join(t1, NULL); return 0; } valgrind –leak-check=full –show-reachable=yes shows 5 blocks allocated from functions called by pthread_exit() that is unfreed but still reachable at process … Read more
You can download Valgrind’s latest version from their website. Then, you can just ./autogen.sh to install Valgrind. I personally did not encounter anything needed to make. However, the sad news is, even the most recent version of Valgrind is not very usable on Mac OS Sierra. The reason is that Apple has not released the … Read more
Use massif, which is part of the Valgrind tools. massif-visualizer can help you graph the data or you can just use the ms_print command.
I think you’ll find this wiki useful. TLDR main advantages of sanitizers are much smaller CPU overheads (Lsan is practically free, UBsan/Isan is 1.25x, Asan and Msan are 2-4x for computationally intensive tasks and 1.05-1.1x for GUIs, Tsan is 5-15x) wider class of detected errors (stack and global overflows, use-after-return/scope) full support of multi-threaded apps … Read more