Re: [PATCH 3/3] KVM: LAPIC: Fix lapic timer injection delay

From: Wanpeng Li
Date: Mon Jul 03 2017 - 04:41:59 EST

2017-07-03 16:16 GMT+08:00 Paolo Bonzini <pbonzini@xxxxxxxxxx>:
> On 03/07/2017 10:08, Wanpeng Li wrote:
>>> Yeah, I'm not entirely satisfied with it but it's working: start_sw
>>> timer will see ktimer->pending and do nothing.
>>> But thinking more about it, maybe the "if (r)" can be omitted
>>> completely? We need to benchmark it but it can be done.
>> "if (r)" makes codes more understandable, in addition, calling expired
>> the pending timer here looks weird though ktimer->pending.
> We can remove the call to apic_timer_expired too (sorry if I was too
> terse). :) start_sw_period and start_sw_tscdeadline would take care of it.

IRQ disable and ktime_get() in start_sw_tscdeadline() are more
expensive. So maybe current status is a better choice. :)

Wanpeng Li