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From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Fri, 11 Aug 2017 09:16:29 -0700
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Subject: Re: [tip:x86/platform] x86/hyper-v: Use hypercall for remote TLB flush
To: Peter Zijlstra <peterz@infradead.org>
Cc: Jork Loeser <Jork.Loeser@microsoft.com>,
        KY Srinivasan <kys@microsoft.com>, Simon Xiao <sixiao@microsoft.com>,
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On Fri, Aug 11, 2017 at 2:03 AM, Peter Zijlstra <peterz@infradead.org> wrote:
>
> I'm sure we talked about using HAVE_RCU_TABLE_FREE for x86 (and yes that
> would make it work again), but this was some years ago and I cannot
> readily find those emails.

I think the only time we really talked about HAVE_RCU_TABLE_FREE for
x86 (at least that I was cc'd on) was not because of RCU freeing, but
because we just wanted to use the generic page table lookup code on
x86 *despite* not using RCU freeing.

And we just ended up renaming HAVE_GENERIC_RCU_GUP as HAVE_GENERIC_GUP.

There was only passing mention of maybe making x86 use RCU, but the
discussion was really about why the IF flag meant that x86 didn't need
to, iirc.

I don't recall us ever discussing *really* making x86 use RCU.

                    Linus