On Thu, 2010-09-30 at 12:58 -0400, Ronan Jouchet wrote: > On Thu, Sep 30, 2010 at 11:45 AM, Ralf Mardorf > <[email protected]> wrote: > > Why does Ubuntu Studio comes without PREEMPT RT, but just PREEMPT?! > > This is my intension. > > > > FWIW, I'm a professional audio and video engineer and did program oldish > > computers and I'm missing hard real-time for modern PCs. Even the > > kernel-rt isn't able to do hard real-time, so I don't understand why > > Ubuntu Studio does prefer a kernel without rt-patch. Today the rt-patch > > isn't good enough and any kernel without this patch is useless for > > multimedia production. > > > > So a misunderstanding ;)! > > Hello Ralf, > > You keep coming back to -rt/-realtime, but nobody ever questioned > their greatness. I trust you when you mention -rt is the ideal > solution in your heavy MIDI use case, and I would also *love* a > properly maintained -rt kernel in Studio. > > Now, whether we want it or not, the facts are: > - Preparing -realtime (vanilla+rtpatch) or -rt > (vanilla+ubuntusauce+rtpatch) is a lot of work and there are no > resources for this > - On the contrary, -lowlatency (generic with some config tweaks) means > performance tradeoff, _but_ could happen in a PPA (maybe even in the > archives in Natty) because it is less of a maintenance hell > > You mention you have some custom built kernels, so if you feel like > helping maintaining -realtime/-rt, by all means step in, talk to > Alessio and make it happen. But insisting again and again on -rt and > -realtime without considering the possibilities is only going to > discourage him from working on the feasible options. > > He tries to propose sustainable options and the only echoes are > negative, without much questioning. What are the results of your own > tests with -lowlatency? What kind of performance drop have you met on > one of your heavy setups? How much latency lost, on which kind of > machine / firewire card? > > Ronan
Hi Ronan :) I marked your email and will come back to it ASAP. At the moment the influenza gained the upper hand. I guess it's not that important what issues I had when using the PREEMPT kernel, there were issues and I didn't noticed that it was a PREEMPT, but a PREEMPT RT kernel, when I posted something, including uname -a at LAD or JACK mailing list. Somebody else noticed it. I might do another test, or search the archives, but I would prefer trying to compile and build a package for a kernel-rt again on my Ubuntu Studio and post the package for 64-bit or ask because of trouble, if the compiling should fail, resp. the startup when booting the kernel should fail. Perhaps I could try to compile a kernel-rt at the weekend. I suspect issues for the startup regarding to X, but I'm not sure. To be continued ... probably this weekend ... if I don't answer until the week after next, please remember me to compile a kernel-rt and to post the messages I get when booting the kernel-rt from the repositories. Today I don't wish to test anything. I've got two PCI Envy24 cards, Terratec EWX 24/96, a NVidia 7200 GS + an onboard Radeon X1250-based graphics. The mobo is a M2A-VM HDMI and suse11-2:/home/spinymouse11.2 # hwinfo --cpu 01: None 00.0: 10103 CPU [Created at cpu.301] Unique ID: rdCR.j8NaKXDZtZ6 Hardware Class: cpu Arch: X86-64 Vendor: "AuthenticAMD" Model: 15.107.2 "AMD Athlon(tm) X2 Dual Core Processor BE-2350" Features: fpu,vme,de,pse,tsc,msr,pae,mce,cx8,apic,sep,mtrr,pge,mca,cmov,pat,pse36,clflush,mmx,fxsr,sse,sse2,ht,syscall,nx,mmxext,fxsr_opt,rdtscp,lm,3dnowext,3dnow,rep_good,extd_apicid,pni,cx16,lahf_lm,cmp_legacy,svm,extapic,cr8_legacy,3dnowprefetch Clock: 1000 MHz BogoMips: 1999.85 Cache: 512 kb Units/Processor: 2 Config Status: cfg=new, avail=yes, need=no, active=unknown 02: None 01.0: 10103 CPU [Created at cpu.301] Unique ID: wkFv.j8NaKXDZtZ6 Hardware Class: cpu Arch: X86-64 Vendor: "AuthenticAMD" Model: 15.107.2 "AMD Athlon(tm) X2 Dual Core Processor BE-2350" Features: fpu,vme,de,pse,tsc,msr,pae,mce,cx8,apic,sep,mtrr,pge,mca,cmov,pat,pse36,clflush,mmx,fxsr,sse,sse2,ht,syscall,nx,mmxext,fxsr_opt,rdtscp,lm,3dnowext,3dnow,rep_good,extd_apicid,pni,cx16,lahf_lm,cmp_legacy,svm,extapic,cr8_legacy,3dnowprefetch Clock: 1000 MHz BogoMips: 1999.85 Cache: 512 kb Units/Processor: 2 Config Status: cfg=new, avail=yes, need=no, active=unknown suse11-2:/home/spinymouse11.2 # hwinfo --memory 01: None 00.0: 10102 Main Memory [Created at memory.61] Unique ID: rdCR.CxwsZFjVASF Hardware Class: memory Model: "Main Memory" Memory Range: 0x00000000-0x7fedffff (rw) Memory Size: 2 GB Config Status: cfg=new, avail=yes, need=no, active=unknown In addition I do have an USB swissonic MIDI device, but it's not connected, because it's better to use the Envy24 PCI card MPU. I try to get a better sound card, but at the moment this is my setup. HDMI and on-board sound disabled. Cheers! Ralf -- Ubuntu-Studio-users mailing list [email protected] Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-studio-users
