On Thu, 2001-10-04 at 08:58, Takashi Iwai wrote: > At 02 Oct 2001 14:25:03 -0700, > Josh Green wrote: > > > > On Tue, 2001-10-02 at 10:33, Takashi Iwai wrote: > > > Hi, > > > > > > i'm trying to run latency test for ALSA9 (based on Benno's latency > > > suite) on my kernel to measure the latency with preemption and LL > > > kernel patches. > > > however, the test program hangs up almost always in the middle during > > > disk write tests of 500 MB. > > > I first though that this is related with VM and happens when the > > > memory becomes full. But it's not true. This happens even if there > > > are enough memory left unused. > > > > > > This appears only on 2.4.10 kernel. Looks like 2.4.9 kernel works > > > fine. > > > > > > Could somebody test the program too? Of course, be prepare for hang > > > up before you try :) > > > > > > The latency test program can be found at: > > > http://www.alsa-project.org/~iwai/latencytest-0.42+alsa.tar.bz2 > > > > > > > > > ciao, > > > > > > Takashi > > > > > > > What are you using for your LL patch? It looks like Andrew Morton's > > patch is only up to 2.4.9. I've applied his 2.4.9 patch to 2.4.10, but > > there are a lot of rejects which I'm currently fixing up to the best of > > my knowledge. > > It's my hacking version (applied not to vanilla but SuSE's kernel). > The kernel itself works flawlessly, but obviously it doesn't work > as expected during heavy disk write. I experienced periodical peaks > up to 6 msec. The disk read and proc load are quite ok. > > It's interesting to compare the results between LL and PE patches. > Usually PE kernel shows much better responce than LL kernel on my > tests. The latency is less than 100 usec, while the LL kernel has > usually 200-500 msec usecs latency. > But both kernels have almos same level peaks in disk write/copy... > > I'll check this problem futhre when I have time.. > > > ciao, > > Takashi >
Aggh.. I just ran a whole bunch of ALSA latencytests with various drivers/kernels, all with fairly bad results :( I even went back to my older kernel (2.4.5 with Andrew Morton's patch) with my AWE 32 card, which I had good results with before, and got like 5 to 8ms spikes. I'm not sure what the heck is going on with my machine now, but its certainly not good. Are there any programs that report what piece of code is causing big spikes? I haven't tested the 2.4.10 kernel yet, and if I did it would be bare without any patches (as I don't know of any up to date with 2.4.10). I did realize that the 2.4.9 kernel with LL patch is worse than the 2.4.5 one I was using. This might be because I compiled it with Mandrake's gcc a la 2.96. I also noticed that the sound heard with your latencytest is not very clean, it has quite a lot of "fuzz" in it. I ran Benno's latencytest program and it sounded much cleaner. Your program also prints out "overrun!" with the ALSA driver, which is probably just for debugging right? I thought of a few improvements that could be done with latencytest. It would be nice if the machine configuration could be generated in the toplevel html file (kernel version/build info, CPU, memory, sound card info, etc). Sometimes its easy to forget the configuration when testing various kernels/drivers/sound cards. By the way I'm posting my results to http://www.c0nfusion.org/~josh/ if you want to have a look. The only hardware that has changed in my machine since my previous tests (http://www.resonance.org/~josh/) is I added an SB Live!. I think I upgraded to Mandrake 8 between then, so most of the software is probably different. -- Josh Green Smurf Sound Font Editor (http://smurf.sourceforge.net) _______________________________________________ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
