Re: [RFC PATCH 00/11] Avoid synchronous TLB invalidation for intermediate page-table entries on arm64

From: Will Deacon
Date: Wed Sep 05 2018 - 08:28:17 EST


On Tue, Sep 04, 2018 at 02:38:02PM -0400, Jon Masters wrote:
> On 08/24/2018 11:52 AM, Will Deacon wrote:
>
> > I hacked up this RFC on the back of the recent changes to the mmu_gather
> > stuff in mainline. It's had a bit of testing and it looks pretty good so
> > far.
>
> I will request the server folks go and test this. You'll probably
> remember a couple of parts we've seen where aggressive walker caches
> ended up (correctly) seeing stale page table entries and we had all
> manner of horrifically hard to debug problems. We have some fairly nice
> reproducers that were able to find this last time that we can test.

Cheers, Jon, that would be very helpful. You're probably best off using
my (rebasing) tlb branch rather than picking the RFC:

git://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git tlb

Let me know if you'd prefer something stable (I can tag it with a date).

Will