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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: kas1e on December 01, 2005, 06:48:25 PM

Title: can some one explain more deep env:powerpc/memprot ?
Post by: kas1e on December 01, 2005, 06:48:25 PM

I am interesting, what this option doing exactly ? In documentation for warp-os i found only this:

"Can be either 0 or 1. If it is set to 1, the memory-protection facilities of WarpOS are switched on, otherwise off. If low-memory situations occur it can help to switch off memory protection."

And nothink more .. Can someone give me some deep explain ?

Title: Re: can some one explain more deep env:powerpc/memprot ?
Post by: Tripitaka on December 02, 2005, 12:02:54 AM

Mem protection is there to stop your system crashing if a program crashes. In turn Mem protection uses a certain amount of memory itself. So leave it on if you can (1) and if you find that you keep running out of memmory, then turn it off (0).....seems clear enough. :-)

Title: Re: can some one explain more deep env:powerpc/memprot ?
Post by: Piru on December 02, 2005, 12:16:07 AM

@kas1e

It's a debugging aid for programmers. Basically it makes WOS throw exception earlier on illegal accesses, so it in fact makes WOS apps die easier. It doesn't prevent WOS apps from nuking the system.

It doesn't make any difference with bug free applications (except some extra mem usage).

Title: Re: can some one explain more deep env:powerpc/memprot ?
Post by: AmigaMance on December 02, 2005, 05:08:51 AM

 does memory protection make your system slower or is it just a myth?

Title: Re: can some one explain more deep env:powerpc/memprot ?
Post by: kas1e on December 02, 2005, 01:22:33 PM

@piru
In other words, env:powerpc/memprot do not give me any difference for crashing programms ?

@amigamance
do you mean real memory protection as on winxp/pc , or memprot for ppc ? for ppc this option do not give me any difference with speed.

Title: Re: can some one explain more deep env:powerpc/memprot ?
Post by: Thomas on December 02, 2005, 01:36:42 PM

Quote

In other words, env:powerpc/memprot do not give me any difference for crashing programms ?

It does make a difference. It causes more programs to crash.

With memory protection every forbidden memory access will cause an exception (crash).

Without memory protection illegal memory accesses are not trapped and do not crash. But they might cause other unpredictable troubles. For example graphics corruption on the Workbench or in other programs or random crashes of otherwise stable programs.

Bye,
Thomas

Title: Re: can some one explain more deep env:powerpc/memprot ?
Post by: AmigaMance on December 02, 2005, 02:45:08 PM

@kas1e
 Yes, i asked mainly for memprot of ppc. Ok, got the answer :-)