Messages in this thread |  | | | Date | Thu, 09 Jul 2009 08:14:50 +0900 | | From | Tejun Heo <> | | Subject | Re: [PATCH 4/4] FUSE: implement direct mmap |
Hello, Miklos.
Miklos Szeredi wrote: > 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?
The desire to avoid pinning all the mapped pages. :-)
> 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.
If pinning all the pages are okay, the above should work fine.
Thanks.
-- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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