使用 valgrind 发现 mpi 代码中的错误

Question

我有一个代码可以完美地串行运行，但使用 mpirun -n 2 ./out 时会出现以下错误：

./out': malloc(): smallbin double linked list corrupted: 0x00000000024aa090

我尝试使用 valgrind，例如：

valgrind --leak-check=yes mpirun -n 2 ./out

我得到以下输出：

==3494== Memcheck, a memory error detector
==3494== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==3494== Using Valgrind-3.11.0 and LibVEX; rerun with -h for copyright info
==3494== Command: mpirun -n 2 ./out
==3494== 
Grid_0/NACA0012.msh
Grid_0/NACA0012.msh
>>> Number of cells: 7734
>>> Number of cells: 7734
0.000000  0         1.470622e-02
*** Error in `./out': malloc(): smallbin double linked list corrupted: 0x00000000024aa090 ***

===================================================================================
=   BAD TERMINATION OF ONE OF YOUR APPLICATION PROCESSES
=   PID 3497 RUNNING AT orhan
=   EXIT CODE: 134
=   CLEANING UP REMAINING PROCESSES
=   YOU CAN IGNORE THE BELOW CLEANUP MESSAGES
===================================================================================
YOUR APPLICATION TERMINATED WITH THE EXIT STRING: Aborted (signal 6)
This typically refers to a problem with your application.
Please see the FAQ page for debugging suggestions
==3494== 
==3494== HEAP SUMMARY:
==3494==     in use at exit: 131,120 bytes in 2 blocks
==3494==   total heap usage: 1,064 allocs, 1,062 frees, 231,859 bytes allocated
==3494== 
==3494== LEAK SUMMARY:
==3494==    definitely lost: 0 bytes in 0 blocks
==3494==    indirectly lost: 0 bytes in 0 blocks
==3494==      possibly lost: 0 bytes in 0 blocks
==3494==    still reachable: 131,120 bytes in 2 blocks
==3494==         suppressed: 0 bytes in 0 blocks
==3494== Reachable blocks (those to which a pointer was found) are not shown.
==3494== To see them, rerun with: --leak-check=full --show-leak-kinds=all
==3494== 
==3494== For counts of detected and suppressed errors, rerun with: -v
==3494== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)

我不擅长 valgrind，但据我所知，valgrind 没问题。 valgrind 是否有更好的选项来发现提到的特定错误的来源？

Answer 1

注意上面的调用，

valgrind --leak-check=yes mpirun -n 2 ./out

你在程序 mpirun 上运行ning valgrind，它可能已经过广泛测试并且工作正常，而不是你知道有问题的程序 ./out .

要运行 valgrind 在你的测试程序上你会想要做的：

mpirun -n 2 valgrind --leak-check=yes ./out

它使用 mpi运行启动 2 个进程，每个运行ning valgrind --leak-check=yes ./out.

Answer 2

乔纳森·杜尔西 (Jonathan Dursi) 的回答永远不会出错，但让我补充一点，使用多个处理器时，读取 valgrind 输出可能会很痛苦。

不是输出到控制台，而是将其转储到日志文件。当然，如果您将两个进程都转储到同一个日志文件中，那将不会有帮助。相反，记录到多个文件——valgrind 将 '%p' 解释为进程 ID，因此您可以获得两个（或更多）日志文件：

mpiexec -np 2 valgrind --leak-check=full \
    --show-reachable=yes --log-file=nc.vg.%p ./noncontig_coll2 -fname blah

使用 valgrind 发现 mpi 代码中的错误

Using valgrind to spot error in mpi code

valgrind

mpi