Messages in this thread | | | From | Andy Lutomirski <> | Date | Tue, 27 Oct 2015 22:20:58 -0700 | Subject | Re: [PATCH 2/3] context_tracking: avoid irq_save/irq_restore on guest entry and exit |
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On Tue, Oct 27, 2015 at 6:39 PM, Paolo Bonzini <pbonzini@redhat.com> wrote: > guest_enter and guest_exit must be called with interrupts disabled, > since they take the vtime_seqlock with write_seq{lock,unlock}. > Therefore, it is not necessary to check for exceptions, nor to > save/restore the IRQ state, when context tracking functions are > called by guest_enter and guest_exit. > > Split the body of context_tracking_entry and context_tracking_exit > out to __-prefixed functions, and use them from KVM. > > Rik van Riel has measured this to speed up a tight vmentry/vmexit > loop by about 2%.
Looks generally sensible. I'm not familiar enough with the code to call it reviewed-by while sitting on the airport shuttle.
--Andy
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