[openib-general] Re: [PATCH 10 of 20] ipath - support for userspace apps using core driver

[Bryan O'Sullivan]

On Thu, 2006-03-09 at 16:01 -0800, Roland Dreier wrote:
>     Bryan> Any idea what I should be using instead?
> 
> It depends what you're trying to do.  Hence my original question: why
> are you doing SetPageReserved?

We're mapping some memory that the chip DMAs to into userspace, so that
user processes can spin on memory locations without going through the
kernel.  The SetPageReserved hack is an attempt to stop the VM from
reclaiming those pages from us once a user process exits.

I realise that it's surely bogus, and I'd be thrilled to do something
correct instead.  We've tried doing both SetPageReserved and get_page,
but it hasn't work out too well so far.

	<b