Re: [hatari-devel] Memory mapped (mmap) image files

[Thorsten Otto <admin@xxxxxxxxxxx>]

On Dienstag, 17. August 2021 15:20:21 CEST Uwe Seimet wrote:

> Hi,

>

> Does anybody of you know whether accessing image files with regular file

> system calls (like Hatari) is faster or slower than mapping those files into

> memory (like RaSCSI)?

>

> Best regards

>

> Uwe

 

 

mmap()ed files are usually much faster, because I/O is done by the kernel directly to your memory, without the overhead of calling file system functions, copying buffers around etc. However on 32bit systems, that may not always be possible, because you run out of virtual memory.

 

Also, on emulators, when you have to simulate reading data from some port (e.g. from the IDE interface), swap data etc, that may not be an option at all.