Re: [PATCH v4 00/10] PCID and improved laziness

From: Ingo Molnar
Date: Wed Jul 05 2017 - 04:57:34 EST

* Andy Lutomirski <luto@xxxxxxxxxx> wrote:

> *** Ingo, even if this misses 4.13, please apply the first patch before
> *** the merge window.

> Andy Lutomirski (10):
> x86/mm: Don't reenter flush_tlb_func_common()
> x86/mm: Delete a big outdated comment about TLB flushing
> x86/mm: Give each mm TLB flush generation a unique ID
> x86/mm: Track the TLB's tlb_gen and update the flushing algorithm
> x86/mm: Rework lazy TLB mode and TLB freshness tracking
> x86/mm: Stop calling leave_mm() in idle code
> x86/mm: Disable PCID on 32-bit kernels
> x86/mm: Add nopcid to turn off PCID
> x86/mm: Enable CR4.PCIDE on supported systems
> x86/mm: Try to preserve old TLB entries using PCID

So this series is really nice, and the first two patches are already upstream, and
I've just applied all but the final patch to tip:x86/mm (out of caution - I'm a wimp).

That should already offer some improvements and enables the CR4 bit - but doesn't
actually use the PCID hardware yet.

I'll push it all out when it passes testing.

If it's all super stable I plan to tempt Linus with a late merge window pull
request for all these preparatory patches. (Unless he objects that is. Hint, hint.)

Any objections?