Re: [PATCH v2 9/9] KVM: X86: Optimize zapping rmap

From: Paolo Bonzini
Date: Thu Jul 29 2021 - 05:35:14 EST


On 29/07/21 00:31, Sean Christopherson wrote:
If that'll be a performance concern, no objection to hard code it.
It's more about unnecessary complexity than it is about performance, e.g. gcc-10
generates identical code for both version (which did surprise the heck out of me).

If you think of what's needed to produce decent (as fast as C) code out of STL code, that's not surprising. :) Pretty cool that it lets people write nicer C code too, though.

If we really want to isolate pte_list_destroy(), I would vote for something like
this (squashed in). pte_list_remove() already calls mmu_spte_clear_track_bits(),
so that particular separation of concerns has already gone out the window.

Yes, that's fair enough. Thanks for the review!

Paolo