Messages in this thread | | | Subject | Re: [PATCH 4/4] FUSE: implement direct mmap | From | Miklos Szeredi <> | Date | Mon, 06 Jul 2009 13:41:12 +0200 |
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On Sat, 04 Jul 2009, Tejun Heo wrote: > > Afaics sound drivers now map the dma memory with remap_pfn_range(). > > Similary we could allocate a chunk of non-swapabble kernel memory on > > request from the userspace server and map its pages using this trick > > to both the server's and the client's address space. > > > > This is still sort of OSSP specific, I don't see clearly how it could > > be made more generic. > > Using non-swappable memory would be fine for most device emulations > but mapping large amount of pages would be problematic. Hmmm... this > is difficult. It's a compromise among flexibility, scalability and > code complexity.
What's the difficulty?
Allocating pages, giving them an ID and mapping them into various page tables seems simple in contrast to trying to make a tmpfs file be a fuse file at the same time, which the VM is really not prepared for.
Thanks, Miklos
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