- From: Ian Hickson <ian@hixie.ch>
- Date: Sat, 29 Dec 2012 07:18:27 +0000 (UTC)
- To: whatwg@whatwg.org
On Tue, 30 Oct 2012, Mikko Rantalainen wrote: > Ian Hickson, 2012-10-27 03:14 (Europe/Helsinki): > > On Thu, 9 Aug 2012, Jussi Kalliokoski wrote: > >> > >> On W3C AudioWG we're currently discussing the possibility of having > >> web workers that run in a priority/RT thread. This would be highly > >> useful for example to keep audio from glitching even under high CPU > >> stress. > >> > >> Thoughts? Is there a big blocker for this that I'm not thinking about > >> or has it just not been discussed yet? (I tried to search for it, but > >> didn't find anything) > > > > I think it's impractical to give Web authors this kind of control. > > User agents should be able to increase the priority of threads, or > > notice a thread is being used for audio and start limiting its > > per-slice CPU but increasing the frequency of its slices, but that > > should be up to the UA, we can't possibly let Web authors control > > this, IMHO. > > Would it be possible to allow web site to request high priority / RT on > the expense of getting explicitly limited time slice? > > For example, API could be something like > > setMaxLatency(latency) > > where latency is desired maximum latency in ns. The return value could > be maximum time slice in ns. If the worker (repeatedly) went over it > maximum time slice, the UA should then revoke the high priority / RT > scheduling from said worker and post some kind of event to worker to let > it know about the issue. > > This would prevent any RT worker from hogging the CPU 100% but any well > written worker code could be run with very low latency. > > Notice that the worker can only request desired latency and UA will then > tell how much CPU time the worker is allowed to use each slice. The UA > should simply return zero if the requested latency is too low to > implement. (In this case, the worker would logically always overrun its > time sclice and would be re-scheduled back to normal latency.) This is an interesting idea. Is it something any browser vendors would be interested in supporting? -- Ian Hickson U+1047E )\._.,--....,'``. fL http://ln.hixie.ch/ U+263A /, _.. \ _\ ;`._ ,. Things that are impossible just take longer. `._.-(,_..'--(,_..'`-.;.'
Received on Saturday, 29 December 2012 07:18:56 UTC