Groups > linux.kernel > #1198931

Re: [PATCH] x86, pat: Add comments to cachemode translation tables

From	Toshi Kani <toshi.kani@hp.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH] x86, pat: Add comments to cachemode translation tables
Date	2015-08-03 17:10 +0200
Message-ID	<pTpxg-6Ex-31@gated-at.bofh.it> (permalink)
References	(3 earlier) <pPq8y-1pC-7@gated-at.bofh.it> <pPqBB-2df-43@gated-at.bofh.it> <pPqLg-2oy-17@gated-at.bofh.it> <pPqUV-2A7-5@gated-at.bofh.it> <pSYnn-Jb-1@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On Sun, 2015-08-02 at 12:07 +0200, Thomas Gleixner wrote:
> On Thu, 23 Jul 2015, Toshi Kani wrote:
> > On Thu, 2015-07-23 at 09:36 -0600, Jan Beulich wrote:
> > > > 
> > > > > > On 23.07.15 at 17:25, <toshi.kani@hp.com> wrote:
> > > > Yes, I agree with you.  But such risk is very low -- 1) the regular 
> > > > case
> > > > (no fallback) is used most of the cases, 2) the code using WT knows 
> > > > what
> > > > type of memory it is dealing with.  For example, pmem may map NVDIMM 
> > > > 
> > > > with
> > > > WT, and any sane BIOS sets MTRR to WB for NVDIMM. 
> > > 
> > > Do the words "sane" and "BIOS" really fit together in your opinion?
> > 
> > :-)
> > 
> > Anyway, I am not disagreeing with you... When UC is ready for both 
> > regular
> > memory and IO memory, it should be changed to fall back to UC.
> 
> What's the resolution of this discussion? Is that patch correct as is
> or do we get an updated version?

Yes, this patch is correct and we are in agreement.

What Jan mentioned about falling back to UC, instead of UC-, is a separate
item, and the code does not support it yet.

Thanks,
-Toshi
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

[PATCH] x86, pat: Add comments to cachemode translation tables Toshi Kani <toshi.kani@hp.com> - 2015-07-22 20:10 +0200
  Re: [PATCH] x86, pat: Add comments to cachemode translation  tables "Jan Beulich" <JBeulich@suse.com> - 2015-07-23 08:50 +0200
    Re: [PATCH] x86, pat: Add comments to cachemode translation tables Thomas Gleixner <tglx@linutronix.de> - 2015-08-02 12:10 +0200
      Re: [PATCH] x86, pat: Add comments to cachemode translation tables Toshi Kani <toshi.kani@hp.com> - 2015-08-03 17:10 +0200

csiph-web