I did discover something interesting though. On a single CPU machine the ck7 patch caused very rough grained scheduling. I tried the 'optimum' SDL demos (http://www.libsdl.org/demos.php) (actually, I think any graphic intensive demos would do fine) with 2 demos running and each would get a big chunk of the CPU time and then lose it for an extended period of time as well. *Interestingly*, running 4 or more demos would cause the scheduling to become more fine-grained!
The problem did not manifest itself with the ck7 patch on an SMP (2-cpu) machine. Nor on a 2.4.18 kernel. Smells like the O(1) scheduler has some rough edges. Also, audio was completely unaffected by these issues (maybe due to aRTS running with realtime priority - do you know how to set this, btw?) and never ever broke up. Actually, not using aRTS for audio also gave just as good results (except of course you don't get to mix audio streams). I should try an LL/PE or just LL patch (no O(1) scheduler) one of these days to see O(1) is the culprit, but I don't know enough about scheduling issues or how XFree works internally yet to pinpoint the culprit and form a good judgement as to a direction to head and am kind of sick of trial and error recompiling kernels for now. Maybe you could try http://members.optusnet.com.au/ckolivas/kernel/llck5_2.4.19.patch.bz2 and tell me what results you get. > Message: 17 > From: "Michael E. Peligro" <[EMAIL PROTECTED]> > Organization: Abbey Road Recording Studios > To: [EMAIL PROTECTED] > Subject: Re: [plug] Re: ckolivas patches > Date: Mon, 23 Sep 2002 11:05:41 +0800 > Reply-To: [EMAIL PROTECTED] > > On Sunday 22 September 2002 09:04 pm, you wrote: > > > IN ADDITION, the patch did nothing for OpenGL/graphics > > latency. The behaviour of xmms' OpenGL spectrum > > analyzer was the same under 2.4.18 and 2.4.19 with > > the ckolivas patches. The animation stutters badly > > when you move a window around. Experiments with > > renicing different threads accomplished nothing 'cept > > to make things even less responsive. Disappointing... > > Not sure if this is due to the way XFree works (no > > pervasive multithreading) or the patches simply aren't > > effective. > > Same here. Whenever I install a new Linux release in my machine, I play an > mp3 in xmms with the OpenGL spectrum analyzer plugin active. Seeing how well > the animation runs somehow provides me with a rough benchmark of the kernel > and Xfree performance combo. I also open a lot of windows and graphic files > to see how well the graphic environment stands up to this stress. > > mikol _ Philippine Linux Users Group. Web site and archives at http://plug.linux.org.ph To leave: send "unsubscribe" in the body to [EMAIL PROTECTED] Fully Searchable Archives With Friendly Web Interface at http://marc.free.net.ph To subscribe to the Linux Newbies' List: send "subscribe" in the body to [EMAIL PROTECTED]
