Maximum memory which malloc can allocate

by

I read that the maximum memory malloc can allocate is limited to physical memory (on heap).

Wrong: most computers/OSs support virtual memory, backed by disk space.

Some questions: does malloc allocate memory from HDD also?

malloc asks the OS, which in turn may well use some disk space.

What was the reason for above behavior? Why didn’t the loop break at any time?

Why wasn’t there any allocation failure?

You just asked for too little at a time: the loop would have broken eventually (well after your machine slowed to a crawl due to the large excess of virtual vs physical memory and the consequent super-frequent disk access, an issue known as “thrashing”) but it exhausted your patience well before then. Try getting e.g. a megabyte at a time instead.

When a program exceeds consumption of memory to a certain level, the
computer stops working because other applications do not get enough
memory that they require.

A total stop is unlikely, but when an operation that normally would take a few microseconds ends up taking (e.g.) tens of milliseconds, those four orders of magnitude may certainly make it feel as if the computer had basically stopped, and what would normally take a minute could take a week.

More Related Contents:

  1. How can I get the size of an array from a pointer in C?
  2. Why is malloc not “using up” the memory on my computer?
  3. How to dynamically allocate memory space for a string and get that string from user?
  4. Create a wrapper function for malloc and free in C
  5. Explain this implementation of malloc from the K&R book
  6. malloc implementation?
  7. Why do I get different results when I dereference a pointer after freeing it?
  8. How do I free memory in C?
  9. Why do you specify the size when using malloc in C?
  10. C: Correctly freeing memory of a multi-dimensional array
  11. What happens if I try to access memory beyond a malloc()’d region?
  12. Is freeing allocated memory needed when exiting a program in C
  13. Why exactly should I not call free() on variables not allocated by malloc()?
  14. Malloc , Realloc , Memset : Struct pointers , arrays of char, int
  15. convert malloc to new c++ for struct
  16. Can x86’s MOV really be “free”? Why can’t I reproduce this at all?
  17. Difference between malloc and calloc?
  18. What’s the difference between a VLA and dynamic memory allocation via malloc?
  19. When and why to use malloc?
  20. What does fflush(stdin) do in C programing? [duplicate]
  21. What is the difference between “new” and “malloc” and “calloc” in C++? [duplicate]
  22. How big can a malloc be in C?
  23. How to include a dynamic array INSIDE a struct in C?
  24. dynamically allocated memory after program termination
  25. Is calloc(4, 6) the same as calloc(6, 4)?
  26. How do realloc and memcpy work?
  27. How are we able to access the pointer after deallocating the memory?
  28. Pipe two or more shell commands in C using a loop
  29. memory allocation in Stack and Heap
  30. /proc/[pid]/pagemaps and /proc/[pid]/maps | linux

Leave a Comment