Messages in this thread | | | From | Vitaly Kuznetsov <> | Subject | Re: [PATCH 4/7] x86,tlb: make lazy TLB mode lazier | Date | Fri, 20 Jul 2018 10:02:10 +0200 |
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Andy Lutomirski <luto@amacapital.net> writes:
> [I added PeterZ and Vitaly -- can you see any way in which this would > break something obscure? I don't.]
Thanks for CCing me,
I don't see how this can break things either. At first glance, however, I'm afraid we can add performance penalty to virtualized guests which don't use native_flush_tlb_others() (Hyper-V, KVM): we will be reloading CR3 without a need as we don't look at lazy mode in PV tlb flush functions.
We can either check to switch_mm_irqs_off() that native_flush_tlb_others() is in use or teach PV tlb flush functions to look at lazy mode too.
(Sorry if I'm missing something important here or if this was already discussed. I just became aware of this work)
[...]
-- Vitaly
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