Messages in this thread | | | Subject | Re: Ideas for memory management hackers (2) | Date | Tue, 18 Nov 1997 11:21:50 +0000 | From | Stephen Williams <> |
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How 'bout a means for device drivers (modules) to lock a stretch of process pages into memory, get physical addresses, and be able to set up i.e. DMA directly into those pages.
NT does support this sort of thing, sorta, with its DIRECT IO. (NT has other problems that make it slow:-)
I understand that it is a bad idea in general, but I am usually faced with devices transferring large images (i.e. 300DPI 11"x17" Gray images) and I find myself getting a bunch of pages, marking them reserved, and using mmap to share them with the process.
(I have a sample module that shows how to do this, if anybody is interested.) -- Steve Williams steve@icarus.com steve@picturel.com
"The woods are lovely, dark and deep. But I have promises to keep, And lines to code before I sleep, And lines to code before I sleep."
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