[ofa-general] Re: [PATCH 08 of 11] anon-vma-rwsem

[Nick Piggin]

On Tue, May 20, 2008 at 05:01:11AM -0500, Robin Holt wrote:
> On Tue, May 20, 2008 at 07:31:46AM +0200, Nick Piggin wrote:
> > 
> > Really? You can get the information through via a sleeping messaging API,
> > but not a non-sleeping one? What is the difference from the hardware POV?
> 
> That was covered in the early very long discussion about 28 seconds.
> The read timeout for the BTE is 28 seconds and it automatically retried
> for certain failures.  In interrupt context, that is 56 seconds without
> any subsequent interrupts of that or lower priority.

I thought you said it would be possible to get the required invalidate
information without using the BTE. Couldn't you use XPMEM pages in
the kernel to read the data out of, if nothing else?