What is Memory Management in C

Memory management in C refers to how programs allocate, use, and free memory during execution. In embedded Linux, this is critical due to limited RAM, real-time constraints, and direct hardware access.

-> C provides manual memory control using

Stack and heap – for automatic vs manual memory

malloc() / calloc() – for dynamic allocation

free() – for releasing memory

Real-World Use Case

In embedded Linux drivers, buffers are dynamically allocated to:

• Store incoming sensor data
• Queue outgoing UART packets
• Manage DMA transfers

Advantages of Manual Memory Management

• Fine-grained control over memory usage
• Efficient use of limited embedded RAM
• Dynamic allocation based on runtime needs

Common Pitfalls

• Memory Leaks: Forgetting to free() allocated memory
• Dangling Pointers: Using memory after it’s freed
• Buffer Overflows: Writing beyond allocated size
• Fragmentation: Frequent allocation/deallocation leads to unusable memory gaps

Kernel-Specific Notes

• Use kmalloc() and kfree() in kernel space
• Avoid malloc() in kernel modules
• Use vmalloc() for large allocations
• Always check return values for NULL

Conclusion

Understanding memory management in C is essential for building reliable embedded Linux applications. Proper allocation, usage, and cleanup prevent crashes, leaks, and performance issues in resource-constrained environments.