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Re: memory mapped files on jffs?




afelson@xxxxxxx.com said:
> Is it possible to create a large contiguous file via jffs on a flash
> device that can be memory mapped so that it can be treated as an
> array?

Yes and no.

You can mmap it read-only. What you can't do is have a shared writable 
mapping. 

We don't support shared writable mappings because it could mean writing out 
a whole 4KiB page each time a single byte on the page is changed. I suppose 
we could play games in writepage() with comparing the contents of the dirty 
page with the previous contents of the file. We don't do that. I don't 
really fancy trying to write it either :)

--
dwmw2



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