Re: [GD-General] responsive threading

[Andras B. <and...@gm...>]

I do wait in the higher priority thread. Actually, this thread spends
90% of the frame time waiting (for vsync)! So the idle thread has
plenty of time, and despite the lower priority, it gets a lot more
CPU, than my primary thread!


Saturday, July 30, 2005, 6:40:15 AM, you wrote:

> If the higher priority thread never ever waits, windows go out of their way
> and give some time to the lower priority thread in that case. Search
> "priority inversion" in MSDN. Perhaps sleeping a bit once in a while in the
> rendering thread to give a slice to the processing thread, might help you
> keep the situation under control.

> HTH,
> Alen

> ----- Original Message ----- 
> From: "Andras Balogh" <and...@gm...>
> To: <gam...@li...>
> Sent: Friday, July 29, 2005 21:22
> Subject: Re: [GD-General] responsive threading


>> I've tried setting the primary thread to time critical and the other
>> thread to idle (and I also disabled it's priority boost), and it does help
>> quite a bit, but I'm still seeing some small glitches. I'm not saying it's
>> bad, it's pretty good actually, and people are so used to bad framerates
>> nowadays that I'm sure they wouldn't complain a tiny bit. I do admit that
>> I'm a bit on the perfectionist side on this one :)
>>
>> I have tried setting the process priority class to real-time too, but in
>> that case my "idle" priority thread won't be really idle anymore, 
>> actually, the hiccups get much worse. I guess I could run in a separate
>> process even, but that's really overkill.
>>
>>
>> Andras
>>
>> Brian Hook wrote:
>>> At the risk of asking the obvious, have you also set your primary thread
>>> to run at the highest priority (REAL_TIME or whatever it's called on
>>> Windows)?
>>>
>>> I run audio mixing in a separate thread and by setting things 
>>> appropriately (and sleeping when necessary) I never get hiccups.
>>>
>>> Brian
>>>
>>> On Fri, 29 Jul 2005 14:35:21 -0600, Andras Balogh wrote:
>>>
>>>>I'm loading lots of "small" (avg. 1k x 1k) regions from lots of
>>>>huge (5GB+) wavelet compressed images. I'm using a 3rd party
>>>>library to do this (ECW), so I don't know the implementation
>>>>details, but I could look at the code, if I knew what to look for..
>>>>
>>>>
>>>>Andras
>>>>
>>>>
>>>>Mat Noguchi (BUNGIE) wrote:
>>>>
>>>>>What else are you doing on the IO thread to make it eat up so
>>>>>much CPU time?
>>>>>
>>>>>MSN
>>>>>-----Original Message-----
>>>>>From: gam...@li...
>>>>>[mailto:gam...@li...] On
>>>>>Behalf Of Andras Balogh Sent: Friday, July 29, 2005 10:44 AM To:
>>>>>gam...@li... Subject: [GD-General]
>>>>>responsive threading
>>>>>
>>>>>I'm developing a graphics application, that I want to be very
>>>>>responsive, very smooth, all the time! The rendering is pretty
>>>>>simple, the framerate is high and stable, so I just lock to
>>>>>vsync, and everything moves beautifully smooth! The CPU usage for
>>>>>this thread is always below 10%.
>>>>>
>>>>>However, I also have another thread, that has to do some heavy
>>>>>work. This thread does tons of IO operations, and also makes the
>>>>>CPU sweat!
>>>>>
>>>>>There is no synchronization between the two threads, so they
>>>>>should be able to run independently. Still, I'm experienceing
>>>>>sudden spikes in the
>>>>>
>>>>>framerate, when the second thread is really hammering. What could
>>>>>be the
>>>>>
>>>>>reason for this? Is it possible to do something about it, to
>>>>>regain the continuous framerate? I'm really not interested in the
>>>>>performance of the second thread, I just want my first thread to
>>>>>run as smooth as possible! I've tried lowering the priority for
>>>>>the second thread, and it
>>>>>
>>>>>does help, but there are still some spikes. Is it possible that
>>>>>it's Windows itself doing some operations at higher priority,
>>>>>like memory management, IO stuff, and the likes?
>>>>>
>>>>>Thanks,
>>>>>
>>>>>
>>>>>Andras