Re: [PATCH 4/9] x86/mm/tlb: Flush remote and local TLBs concurrently

From: Nadav Amit
Date: Tue Jun 25 2019 - 23:48:57 EST


> On Jun 25, 2019, at 8:36 PM, Andy Lutomirski <luto@xxxxxxxxxx> wrote:
>
> On Wed, Jun 12, 2019 at 11:49 PM Nadav Amit <namit@xxxxxxxxxx> wrote:
>> To improve TLB shootdown performance, flush the remote and local TLBs
>> concurrently. Introduce flush_tlb_multi() that does so. The current
>> flush_tlb_others() interface is kept, since paravirtual interfaces need
>> to be adapted first before it can be removed. This is left for future
>> work. In such PV environments, TLB flushes are not performed, at this
>> time, concurrently.
>
> Would it be straightforward to have a default PV flush_tlb_multi()
> that uses flush_tlb_others() under the hood?

I prefer not to have a default PV implementation that should anyhow go away.

I can create unoptimized untested versions for Xen and Hyper-V, if you want.