Re: still nfs problems [Was: Linux 2.6.37-rc8]

From: Linus Torvalds
Date: Wed Jan 05 2011 - 18:29:18 EST


On Wed, Jan 5, 2011 at 3:06 PM, Trond Myklebust
<Trond.Myklebust@xxxxxxxxxx> wrote:
>
> Yes. The fix I sent out was a call to invalidate_kernel_vmap_range(),
> which takes care of invalidating the cache prior to a virtual address
> read.
>
> My question was specifically about the write through the regular kernel
> mapping: according to Russell and my reading of the cachetlb.txt
> documentation, flush_dcache_page() is only guaranteed to have an effect
> on page cache pages.

I don't think that should ever matter. It's not like the hardware can
know whether it's a dcache page or not.

And if the sw implementation cares, it's doing something really odd.
But who knows - there's a lot of crap out there, and people sometimes
do really odd things to work around the brokenness of a VIVT cache
with aliases.

Linus
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