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Unread 31-01-2015, 09:25
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wireties wireties is offline
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AKA: Keith Buchanan
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Re: RoboRIO won't let us use more than 50mb of RAM?

Quote:
Originally Posted by magnets View Post
When the user code has been killed, background processes use 151 mb of the 256 mb. I don't know why this is so much (I guess linux isn't as small as it once was), but it's not unreasonable, considering there's networking, communications, web server, ftp, ssh....
Note that is it difficult to get a number for free memory with Linux. The kernel will increase the amount of memory it uses for file and network I/O when physical pages are available. But as more pages are requested from user space the kernel will back off and release memory.

Also, in user space, Linux will allow one to allocate MUCH more memory than actually exists. This is called "lazy allocation". The maps between the virtual pages allocated and the physical pages are only made when you write to a page (page by page).

HTH
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