Implement THREAD_PRIORITY_TIME_CRITICAL

[Aneurin Price]

Mike Hearn wrote:
>> I'm not convinced this is true. At least some (maybe most or all) of 
>> the games showing this problem work just fine if true OSS (ie. not 
>> ALSA-emulated OSS) is used as the sound driver. WoW and StarCraft 
>> spring to mind immediately. Plus apparently they work in Cedega 
>> without needing to be root, though I have no first-hand experience of 
>> this.
> 
> Maybe for you, but this problem seems to be related to all kinds of 
> things ... system speed, kernel scheduler, driver combinations, what 
> Wine is doing at the time etc. All I know is that this works great for 
> me, and no, rebuilding my kernel and going back to OSS is not really an 
> option :)
> 
> Cedega, IIRC, either has some awful hacks or has the wineserver acquire 
> the privs, I don't remember which .... it'd be nice to find out.
> 
> IMHO the best way would be for wineserver to be suid root and then drop 
> privs. It works everywhere and is simple.

I really ought to remember to use reply-all for wine-devel. I've quoted 
my first post since I meant to send it to the list.

Anyway, surely the `best' way would be for the kernel to support 
user-level `real-time' priorities like the ck kernels. Anybody know why 
they don't like the idea of that kind of thing?

More on topic, does this simply change Wine's priority or does it act on 
a per-thread level? Most of the issues I've seen have been caused by the 
audio thread being starved by the others, and is often semi-solved by 
running Wine at nice 19, which seems counter-intuitive but appears to 
get around some sheduling problems (priority inversions spring to mind). 
This has the side effect of course that you have to make sure no other 
process is going to steal the cpu time from under you. Am I talking 
about the same issue as everyone else or have I got the wrong end of the 
stick?