On 11/12/2014 04:07, Marcelo Tosatti wrote: >> > So, on APICv, if the interrupt is in PIR but it has bits 7:4 <= >> > PPR[7:4], you have a problem. :( There is no APICv hook that lets you >> > get a vmexit when the PPR becomes low enough. > Well, you simply exit earlier and busy spin for VM-exit > time.
Okay, given how small the jitter is in your plots, a small busy wait is not the end of the world even if it caused a very short priority inversion. Can you add a tracepoint that triggers when you do the busy wait, and possibly a kvm stat that counts good (no busy wait) vs. bad (busy wait) invocations of wait_lapic_expire? Thanks, Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
