On Thu, Jan 14, 2010 at 11:41:26AM +0100, Philipp ??berbacher wrote: > Excerpts from Ken Restivo's message of Thu Jan 14 02:38:04 +0100 2010: > > I've been running Fons's great Auto-Wah on my 32-bit Netbook for many months > > now, using it live constantly, and I love it. > > > > I'm going into the studio Friday, so I've dusted off my 64-bit Core 2 Duo > > system and putting it through its paces. > > > > Turns out that on my Core2Duo, JACK RACK running Fons's auto-wah plugin sucks > > up 6% CPU even if there is no sound going through it. > > > > I asked Fons about it; he can't duplicate the problem since he doesn't have a > > 64-bit system. Hell, I can't even duplicate it on my 32-bit system; it's 64-bit > > dependent. > > > > I looked at the output with Bitmeter at Fons' suggestion, and it seems there > > are no denormals, inf's, or nans-- just a very small -230dB DC offset in the > > code (probably to avoid denormals). > > > > The CPU usage ramps up before any signal is fed into the plugin. It runs > > normally when there is signal, but then it keeps sucking up CPU afterwards. I'm > > feeding it from fluidsynth, and bitmeter says that it isn't sending anthing at > > all during silent moments. > > > > It doesn't run away to 99% CPU (or 50% on a Core2Duo), like it would if there > > were a denormal. But still, why is it using up CPU when there's no signal? That > > seems odd. And why only on my 64-bit machine? FWIW, the 64-bit and 32-bit > > machines I have are even running the same kernel and RT-patch versions > > (2.6.26.8-rt12). > > > > Can someone with a 64-bit system help me by trying to duplicate the problem? > > I'm looking to see if JACK-RACK running just Fons' plugin uses as much CPU with > > silence as when there's signal running through it. > > > > Oh, and in case it's setting-dependent, here is the rack with the settings I'm > > using: > > > > http://restivo.org/misc/clavy-phaser.rack > > > > -ken > > Hi Ken. > I'm on 64 bit, so I thought I give it a shot, however, my 64 bit system > is a bit unusual since it's only a single core celeron. > > The result is vastly different from yours, cpu usage of jack-rack in > htop is 0.0% most of the time, occasionally it shows 1.0%, so not even > when running it shows the 6% you get. > I only give it some webradio from mplayer, and it doesn't seem to matter > whether it's playing or not or whether it's connected, it's all the > same. I was clever enough to enable the plugin in jack-rack. > > What I do get around 6% is mem usage (out of 1GB). > What are your JACK period settings? Is it less than 64? Mine are -R -P70 -dalsa -X seq -r48000 -p128 -n3 -Phw:1,0 -Chw:1,1 Fons' code is like a finely-crafted jewel, and it is written in a terse style that looks to me like hand-optimised ASM code (i.e., variable names that are more like register names: "_s1", "gy", "dx"), but I'm starting to understand it a little bit. It looks like he's windowing through the frames, and if the frame is > 80 bytes, he windows through it in 64-byte increments. I am using 3 periods of 128bytes each. -ken _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
