Messages in this thread | | | Date | Fri, 20 Oct 2000 19:39:21 +0200 | From | Andrea Arcangeli <> | Subject | Re: VM_RESERVED [was Re: mapping user space buffer to kernel address space] |
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On Fri, Oct 20, 2000 at 10:10:05AM -0700, Linus Torvalds wrote: > Sure. I have no problem at all with this suggestion: it's basically just a > hint to the VM layer that trying to page something out in this vma is > useless, as its backing store is in memory anyway.
Yes, that is _exactly_ the point.
> As to your rvmalloc()/rvfree() changes, I don't think they are safe as-is: > I think it's the right thing to do, but I don't trust the drivers to > maintain the right page counts. The code used to mark the pages as > reserved, which probably means that it hides bad drivers that do not do > proper reference counting - and I'm not willing to make that kind of > change at this point.
The page count of the mapped pages should be ok, it seems those mapped pages have a reference count of 1 just from the vmalloc allocation and they use PG_reserved just to skip swap_out, but I feel safer too if the bttv maintainers will check it and send it to you themself after checking it's correct. (I only verified that it was compiling correctly)
Thanks.
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