Re: [PATCH v2 6/7] x86, mm: Support huge I/O mappings on x86
From: Toshi Kani
Date: Wed Feb 18 2015 - 17:14:46 EST
On Wed, 2015-02-18 at 22:57 +0100, Ingo Molnar wrote:
> * Toshi Kani <toshi.kani@xxxxxx> wrote:
> > On Wed, 2015-02-18 at 22:15 +0100, Ingo Molnar wrote:
> > > * Toshi Kani <toshi.kani@xxxxxx> wrote:
> > >
> > > > On Wed, 2015-02-18 at 21:44 +0100, Ingo Molnar wrote:
> > > > [...] That said, since the patchset also added a new
> > > > nohugeiomap boot option for the same purpose, I agree
> > > > that this Kconfig option can be removed. So, I will
> > > > remove it in the next version.
> > > >
> > > > An example of such case is with multiple MTRRs described
> > > > in patch 0/7.
> > >
> > > So the multi-MTRR case should probably be detected and
> > > handled safely?
> > I considered two options to safely handle this case, i.e.
> > option A) and B) described in the link below.
> > https://lkml.org/lkml/2015/2/5/638
> > I thought about how much complication we should put into
> > the code for an imaginable platform with a combination of
> > new NVM (or large I/O range) and legacy MTRRs with
> > multi-types & contiguous ranges. My thinking is that we
> > should go with option C) for simplicity, and implement A)
> > or B) later if we find it necessary.
> Well, why not option D):
> D) detect unaligned requests and reject them
That sounds like a good idea! I will work on it.
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/