Memory defrag - any tool available?

[Zac67]

Actually 'defraging' your physical memory is completely impossible as there's no way to tell running processes to relocate their data. And there's no way to find out yourself where all the pointers are.
With the help of the MMU it would be possible to re-align the non-allocated tile sized memory chunks into one single chunk (thus creating additional logical memory), but there's no such tool around afaik.
Logical memory can create problems with allocating buffers for DMA, too...

[SHADES]

@Zac67
Surely there is a lookup table or something for the system. How would the system know where memory is allocated to what program or where it can find free memory otherwise.
If a memory defrag program can also look at this table, it would probably be possible to create some sort of defrag.

[MskoDestny]

SHADES wrote:
@Zac67
Surely there is a lookup table or something for the system. How would the system know where memory is allocated to what program or where it can find free memory otherwise.

The OS knows where the free and allocated memory is. The problem is that the OS has no way of telling the application using the memory that the memory allocated to it has moved (PalmOS has a mechanism for this, but it requires software to be written specifically to take advantage of it).

The most a utility could do (short of mucking about with the MMU) is join contiquous free blocks in the free memory list, but I would hope the OS does this by itself.

[Doobrey]

MskoDestny wrote:
The most a utility could do (short of mucking about with the MMU) is join contiquous free blocks in the free memory list, but I would hope the OS does this by itself.

Wouldn't that mean all of exec's memory functions would have to be patched too to take into account the page sizes used by the MMU.. and if so, wouldn't it make AllocMem/AllocVec etc wastefull for small allocations(Or does exec already have a minimum size to stop the memory lists getting stupidly long)?

[AmigaMance]

 Yeah, patches like FragCure will do the job. But, i wonder if they interfere somehow with the allocmem/freemem functions of the newer execs, like exec44 and 45.

[Dr_Righteous]

Heh, guess no one thought to write EMM680x0