Re: [PATCH v11 3/4] softmmu/dirtylimit: implement virtual CPU throttle

[Peter Xu]

On Sat, Jan 22, 2022 at 11:54:07AM +0800, Hyman Huang wrote:
> 
> > > +static void *dirtylimit_thread(void *opaque)
> > > +{
> > > +    CPUState *cpu;
> > > +
> > > +    rcu_register_thread();
> > > +
> > > +    while (!qatomic_read(&dirtylimit_quit)) {
> > > +        sleep(DIRTYLIMIT_CALC_TIME_MS / 1000);
> > 
> > Sorry to have not mentioned this: I think we probably don't even need this
> > dirtylimit thread.
> > 
> > It'll be hard to make the "sleep" right here.. you could read two identical
> > values from the dirty calc thread because the 1sec sleep is not accurate, so
> > even after this sleep() the calc thread may not have provided the latest 
> > number
> > yet.
> > 
> > It'll be much cleaner (and most importantly, accurate..) to me if we could 
> > make
> > this a hook function being passed over to the vcpu_dirty_rate_stat_thread()
> > thread, then after each vcpu_dirty_rate_stat_collect() we call the hook

Another cut-off email?  Please try again?.. :)

-- 
Peter Xu