Minimizing the amount of malloc() calls improves performance?

by

You asked 2 questions:

  • for which application the next malloc() call will be faster, #1 or #2?
  • In other words: Does malloc() have an index of allocated locations in memory?

You’ve implied that they are the same question, but they are not. The answer to the latter question is YES.

As for which will be faster, it is impossible to say. It depends on the allocator algorithm, the machine state, the fragmentation in the current process, and so on.

Your idea is sound, though: you should think about how malloc usage will affect performance.
There was once an app I wrote that used lots of little blobs of memory, each allocated with malloc(). It worked correctly but was slow. I replaced the many calls to malloc with just one, and then sliced up that large block within my app. It was much much faster.

I don’t recommend this approach; it’s just an illustration of the point that malloc usage can materially affect performance.

My advice is to measure it.

More Related Contents:

  1. How can I get the size of an array from a pointer in C?
  2. Why is it safer to use sizeof(*pointer) in malloc
  3. What’s the point of malloc(0)?
  4. Dynamic memory access only works inside function
  5. Why is malloc not “using up” the memory on my computer?
  6. newbie questions about malloc and sizeof
  7. How can I allocate memory and return it (via a pointer-parameter) to the calling function?
  8. sprintf() with automatic memory allocation?
  9. How to dynamically allocate memory space for a string and get that string from user?
  10. How is malloc() implemented internally? [duplicate]
  11. Maximum memory which malloc can allocate
  12. aligned malloc() in GCC?
  13. free char*: invalid next size (fast) [duplicate]
  14. malloced array VS. variable-length-array [duplicate]
  15. How to use realloc in a function in C
  16. C – Accessing data AFTER memory has been free()ed?
  17. Dynamically create an array of strings with malloc
  18. allocate matrix in C
  19. C Warning: Function returns address of local variable
  20. Do I really need malloc?
  21. malloc(sizeof(int)) vs malloc(sizeof(int *)) vs (int *)malloc(sizeof(int))
  22. malloc implementation?
  23. Getting the size of a malloc only with the returned pointer
  24. Using sizeof() on malloc’d memory [duplicate]
  25. Why do I get a warning every time I use malloc?
  26. An alternative for the deprecated __malloc_hook functionality of glibc
  27. Why does this intentionally incorrect use of strcpy not fail horribly?
  28. realloc(): invalid next size when reallocating to make space for strcat on char * [duplicate]
  29. Is null character included while allocating using malloc
  30. zero size malloc [duplicate]

Leave a Comment