Re: [PATCH v12 0/10] Support Write-Through mapping on x86

From: Luis R. Rodriguez
Date: Tue Jun 02 2015 - 16:02:09 EST


On Tue, Jun 02, 2015 at 12:50:09PM -0700, Andy Lutomirski wrote:
> On Tue, Jun 2, 2015 at 12:43 PM, Luis R. Rodriguez <mcgrof@xxxxxxxx> wrote:
> > On Tue, Jun 02, 2015 at 12:46:48PM -0600, Toshi Kani wrote:
> >> On Tue, 2015-06-02 at 18:21 +0200, Luis R. Rodriguez wrote:
> >> > On Mon, Jun 01, 2015 at 01:36:23PM -0600, Toshi Kani wrote:
> >> > > This patchset adds support of Write-Through (WT) mapping on x86.
> >> > > The study below shows that using WT mapping may be useful for
> >> > > non-volatile memory.
> >> > >
> >> > > http://www.hpl.hp.com/techreports/2012/HPL-2012-236.pdf
> >> > >
> >> > > The patchset consists of the following changes.
> >> > > - Patch 1/10 to 6/10 add ioremap_wt()
> >> > > - Patch 7/10 adds pgprot_writethrough()
> >> > > - Patch 8/10 to 9/10 add set_memory_wt()
> >> > > - Patch 10/10 changes the pmem driver to call ioremap_wt()
> >> > >
> >> > > All new/modified interfaces have been tested.
> >> > >
> >> > > The patchset is based on:
> >> > > git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp.git#tip-mm-2
> >> >
> >> > While at it can you also look at:
> >> >
> >> > mcgrof@ergon ~/linux-next (git::master)$ git grep -4 "writethrough" drivers/infiniband/
> >>
> >> Thanks for checking this. The inifiniband driver uses WT mappings on
> >> powerpc without proper WT interfaces defined.
> >
> > Right.
> >
> >> They can be cleaned up by
> >> a separate patch series to support WT on powerpc in the same way after
> >> this patchset (support WT on x86) is settled.
> >
> > Who's gonna do that work though? How much work is it ? Is it too much to ask
> > to roll it in this series?
> >
>
> I think the driver maintainers should do it. For all I know,
> something will go horribly wrong if those drivers suddenly start using
> WT on x86.

OK. Letting qib driver folks know.

Luis
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