Comments on: Firmware-Specific Bug #5: Heap Fragmentation

By: Firmware-Specific Bug #6: Memory Leak « Barr Code

Firmware-Specific Bug #6: Memory Leak « Barr Code — Fri, 28 Jan 2011 20:27:58 +0000

[...] Unlike fragmentation, memory leaks can happen even with fixed-size [...]

By: Notan

Notan — Thu, 16 Dec 2010 19:51:29 +0000

There is another problem with heap fragmentation. The heap administration of a popular real-time system was structured as several lists of free fragments of increasing sizes.
The first list held small chunks of 12 to 28 bytes, in a system with plenty of memory (standard PC) the system significantly slowed down when it ran for several days. The problem was due to fragmentation, because the 12 to 60 byte list had some thousand 12 byte chunks at the beginning resulting in a lengthy loop, whenever a chunk of 20 byte was allocated.

By: Boudewijn

Boudewijn — Tue, 23 Mar 2010 16:35:31 +0000

All data structures created via C’s malloc() standard library routine or C++’s new keyword _DO_NOT_NECESSARILY_ live on the heap! They live on whatever the C/C++ library implementer chose to implement. In some cases, they actually do use the RTOS’ memory pool API, which can be fixed-size chunks, or a limited number of sizes, tuned to the application.