Re: [LAD] cpu spikes

I used 3.18.25 from kernel.org, applied this patch: patch-3.18.25-rt23.patch.gz . The only option is changed from the default was "Fully Preemptible Kernel (RT)”. After that I had to edit

Re: [LAD] cpu spikes

Hi all, I just wanted to give you an update on my quest for super-low-latency. I bit the bullet and compiled a rt-kernel. And the result is super-stable audio with a period of 32 samples @48Khz (for a total roundtrip latency of 3.5ms). With a (peak) cpu load hovering around 70% on all 4 cores

Re: [LAD] cpu spikes

On Mon, 8 Feb 2016 11:14:45 +, Harry van Haaren wrote: >I think it would be great if the Linux Audio community built up a list >of kernel config options that need changing for optimal audio >performance. Indeed, the rt config became tricky a while ago, especially for AMD based machines.

Re: [LAD] cpu spikes

On Mon, Feb 8, 2016 at 10:07 AM, Fokke de Jong wrote: > And the result is super-stable audio with a period of 32 samples @48Khz > (for a total roundtrip latency of 3.5ms). > Congrats, that's pretty solid! Would you share some details on what config options you used, and

Re: [LAD] cpu spikes

On 02/08/2016 12:14 PM, Harry van Haaren wrote: > I think it would be great if the Linux Audio community built up a list of > kernel config options that need changing for optimal audio performance. +1. I guess everybody is just enabling PREEMPT_RT_FULL and that's about it. Jeremy

Re: [LAD] cpu spikes

On Mon, 8 Feb 2016 21:31:08 +0100, Jeremy Jongepier wrote: >On 02/08/2016 08:11 PM, Ralf Mardorf wrote: >> I forgot to mention, the lowlatency is a vanilla kernel with a >> special configuration, but without a realtime related patch. > >Afaik the Ubuntu low-latency kernel doesn't really have a

Re: [LAD] cpu spikes

On Mon, 8 Feb 2016 19:44:49 +0100, Cedric Roux wrote: >Hi, > >On 02/08/2016 11:07 AM, Fokke de Jong wrote: >> Hi all, >> >> I just wanted to give you an update on my quest for >> super-low-latency. I bit the bullet and compiled a rt-kernel. > >call me noob but did you download a special kernel

Re: [LAD] cpu spikes

On 02/08/2016 08:11 PM, Ralf Mardorf wrote: > I forgot to mention, the lowlatency is a vanilla kernel with a special > configuration, but without a realtime related patch. Afaik the Ubuntu low-latency kernel doesn't really have a special config, just CONFIG_PREEMPT and CONFIG_HZ_1000. Jeremy

Re: [LAD] cpu spikes

Hi, On 02/08/2016 11:07 AM, Fokke de Jong wrote: Hi all, I just wanted to give you an update on my quest for super-low-latency. I bit the bullet and compiled a rt-kernel. call me noob but did you download a special kernel or is it the mainline with just config set in it? I ask because at

Re: [LAD] cpu spikes

PS: I forgot to mention, the lowlatency is a vanilla kernel with a special configuration, but without a realtime related patch. The default kernels of common distros should already provide some level of soft realtime ability if you boot with the 'threadirqs' option, e.g. by the /boot entry of a

Re: [LAD] cpu spikes

On Mon, 1 Feb 2016 09:26:28 +0100, Christopher Arndt wrote: >> RTIRQ_NAME_LIST="usb" >> https://wiki.archlinux.org/index.php/Pro_Audio#M-Audio_Fast_Track_Pro > >How does the latter lead to the former? It latter does provide additional information regarding this card. The former is what you need

Re: [LAD] cpu spikes

On Mon, 1 Feb 2016 07:14:46 +0100, Christopher Arndt wrote: >Am 24.01.2016 um 16:24 schrieb Harry van Haaren: >> I've written up some of the checks I generally do, perhaps browse >> that to see if there's anything there that you could check? >>

Re: [LAD] cpu spikes

Am 01.02.2016 um 09:15 schrieb Ralf Mardorf: > RTIRQ_NAME_LIST="usb" > https://wiki.archlinux.org/index.php/Pro_Audio#M-Audio_Fast_Track_Pro How does the latter lead to the former? > http://lmgtfy.com/?q=uca222+linux Oh dang, hadn't thought of that! Thanks for nothing. Chris signature.asc

Re: [LAD] cpu spikes

PS: >On Mon, 1 Feb 2016 09:26:28 +0100, Christopher Arndt wrote: >>> RTIRQ_NAME_LIST="usb" >>> https://wiki.archlinux.org/index.php/Pro_Audio#M-Audio_Fast_Track_Pro >> >>How does the latter lead to the former? > >It latter does provide additional information regarding this card. The >former

Re: [LAD] cpu spikes

Am 24.01.2016 um 16:24 schrieb Harry van Haaren: > I've written up some of the checks I generally do, perhaps browse > that to see if there's anything there that you could check? > http://openavproductions.com/real-time-latency-tuning/ I'm trying to follow that guide but I am stuck on how to find

Re: [LAD] cpu spikes

On Thu, 28 Jan 2016 07:37:47 -0600 "Jonathan E. Brickman" wrote: > First of all, for the record, anyone who equates firsthand > experiences with snakeoil, shall find their words completely ignored > by yours truly :-) It's not my intention to denigrate your experience,

Re: [LAD] cpu spikes

On Tue, 26 Jan 2016 20:53:55 +0100 Jeremy Jongepier wrote: > On 01/25/2016 12:53 PM, Joakim Hernberg wrote: > > 3. Run Jack with realtime and memlocking enabled and at a priority > > of 80. > > Does this refer to the -m jackd option? What does that do actually, > any

Re: [LAD] cpu spikes

On Fri, Jan 29, 2016 at 07:44:25AM +1100, Erik de Castro Lopo wrote: > Jonathan E. Brickman wrote: > > > I do think you will probably see more stability if you use JACK in such > > efforts, or even PulseAudio, than if you use direct ALSA. I have found > > ALSA to be great for drivers, not

Re: [LAD] cpu spikes

Jonathan E. Brickman wrote: > I do think you will probably see more stability if you use JACK in such > efforts, or even PulseAudio, than if you use direct ALSA. I have found > ALSA to be great for drivers, not anywhere near so good for the > transport phases. Doesn't JACK sit on top of

Re: [LAD] cpu spikes

First of all, for the record, anyone who equates firsthand experiences with snakeoil, shall find their words completely ignored by yours truly :-) First of all, booting into console mode, rather than running the full blown desktop seemed to eliminate most of the problems, although it’s still

Re: [LAD] cpu spikes

On Wed, 27 Jan 2016, Fokke de Jong wrote: 16: 0 0 0 0 IO-APIC 16-fasteoi madifx The madifx is my sound card. I have no idea what the fasteoi is though…(anyone ?) Hmm, I have looked as best I can and it seems fasteoi is an interupt translator

Re: [LAD] cpu spikes

> >> 16: 0 0 0 0 IO-APIC 16-fasteoi >> madifx > The madifx is my sound card. I have no idea what the fasteoi is though…(anyone ?) I have have 3 PCIe slots, one of them and the cars doesn’t show up at all, the other 2 both have the result above. The

Re: [LAD] cpu spikes

On 01/25/2016 12:53 PM, Joakim Hernberg wrote: > 3. Run Jack with realtime and memlocking enabled and at a priority of > 80. Does this refer to the -m jackd option? What does that do actually, any pros/cons? Jeremy signature.asc Description: OpenPGP digital signature

Re: [LAD] cpu spikes

On 01/26/2016 08:53 PM, Jeremy Jongepier wrote: > On 01/25/2016 12:53 PM, Joakim Hernberg wrote: >> 3. Run Jack with realtime and memlocking enabled and at a priority of >> 80. > > Does this refer to the -m jackd option? What does that do actually, any > pros/cons? Nevermind, first try a certain

Re: [LAD] cpu spikes

On 01/26/2016 09:05 PM, Jeremy Jongepier wrote: > Nevermind, first try a certain search engine and then ask ;) I guess > it's preferable to have JACK not lock physical memory but do it's things > in virtual memory. Which should be the other way around of course... /me hides somewhere in a corner

Re: [LAD] cpu spikes

On Tue, 26 Jan 2016 22:15:44 +0100 Jeremy Jongepier wrote: > On 01/26/2016 09:05 PM, Jeremy Jongepier wrote: > > Nevermind, first try a certain search engine and then ask ;) I guess > > it's preferable to have JACK not lock physical memory but do it's things > > in virtual

Re: [LAD] cpu spikes

thanks for all your input, I’ll try and summarize here. > You're running Mint :-) Lots of background bells and whistles there, lots of > things which will crop up and interfere, things you cannot disable or turn > off with absolute certainty. If you want smooth power, you'll have to choose

Re: [LAD] cpu spikes

On Mon, 25 Jan 2016, Joakim Hernberg wrote: I suppose hyperthreading could be a potential pitfall, but personally I see no problems with it with my audio workloads on my i7. hyperthread is only a problem with jack latency under 64/2... even on an older single core P4. (at least in my

Re: [LAD] cpu spikes

On Mon, 25 Jan 2016, Len Ovens wrote: I am sure some will say that if rtirq doesn't help there is a bad driver... Check the actual priorities that rtirq sets. It seems to me the last time I checked that if an irq is shared by a, b an c and rtirq is used to prioritize c to 90 for example, a

Re: [LAD] cpu spikes

On Mon, 25 Jan 2016, Fokke de Jong wrote:   16:          0          0          0          0   IO-APIC   16-fasteoi   madifx Is this your audio interface on irq 16? If so why is it sharing an IRQ? Move it to a different slot maybe? If this is a PCI card and there is only one slot, I would

Re: [LAD] cpu spikes

On Mon, 25 Jan 2016, Jörn Nettingsmeier wrote: sorry to hijack this thread, but: when enquiring about latency tuning, one frequently encounters hints like "disable cron", "disable indexing services", "disable this, disable that". however, none of those alleged culprits run with real-time

Re: [LAD] cpu spikes

[Fokke de Jong] >I’m processing 32 sample-blocks at 48KHz but roughly every 0,6 >seconds I get a large spike in cpu usage. This cannot possibly be >explained by my algorithm, because the load should be pretty stable. > >I am measuring cpu load by getting the time with

Re: [LAD] cpu spikes

On Mon, 25 Jan 2016 12:53:57 +0100 Joakim Hernberg wrote: > On Mon, 25 Jan 2016 12:23:09 +0100 > Jörn Nettingsmeier wrote: > > > i understand how device drivers can be nasty (graphics cards locking > > up the pci bus, wifi chips hogging the

Re: [LAD] cpu spikes

On Mon, 25 Jan 2016 06:57:14 -0800 (PST) Len Ovens wrote: > On Mon, 25 Jan 2016, Joakim Hernberg wrote: > > > I suppose hyperthreading could be a potential pitfall, but > > personally I see no problems with it with my audio workloads on my > > i7. > > hyperthread is only

Re: [LAD] cpu spikes

hi *! sorry to hijack this thread, but: when enquiring about latency tuning, one frequently encounters hints like "disable cron", "disable indexing services", "disable this, disable that". however, none of those alleged culprits run with real-time privileges or access driver or kernel code

Re: [LAD] cpu spikes

On Sun, 24 Jan 2016 15:03:08 +0100 Fokke de Jong wrote: > I am measuring cpu load by getting the time with > clock_gettime(CLOCK_MONOTONIC_RAW, timespec*) at the beginning and > end of each callback. When converted to a percentage my cpu load > hovers somewhere between 40

Re: [LAD] cpu spikes

On Mon, 25 Jan 2016 12:23:09 +0100 Jörn Nettingsmeier wrote: > i understand how device drivers can be nasty (graphics cards locking > up the pci bus, wifi chips hogging the kernel for milliseconds at a > time or worse...) but it seems that a) either kernel

[LAD] cpu spikes

Hi all, This is my first post here. I’m note new to audio programming or linux, but I haven’t done much in terms of combining the two. Most of my audio programming has been on os x. Currently working on some realtime convolution with lots of channels and low latency requirements, but I am

Re: [LAD] cpu spikes

On Sun, Jan 24, 2016 at 03:03:08PM +0100, Fokke de Jong wrote: > I remember reading somewhere that realtime threads cannot run > more than .95s every second. That would be very bad if it > actually meant my threads are blocked run for a period of 50ms > straight… If your normal load is around

Re: [LAD] cpu spikes

On Sun, 24 Jan 2016, Fokke de Jong wrote: I’m processing 32 sample-blocks at 48KHz but roughly every 0,6 seconds I get a large spike in cpu usage. This cannot possibly be explained by my algorithm, because the load should be pretty stable.  ... I’m running (more or less default install, no

Re: [LAD] cpu spikes

On Sun, Jan 24, 2016 at 2:03 PM, Fokke de Jong wrote: > Currently working on some realtime convolution with lots of channels and > low latency requirements, but I am running into some unexpected cpu-spikes > and hope some of you might have an idea of possible causes. >

Re: [LAD] cpu spikes

On 01/24/2016 08:03 AM, Fokke de Jong wrote: Hi all, This is my first post here. I’m note new to audio programming or linux, but I haven’t done much in terms of combining the two. Most of my audio programming has been on os x. Currently working on some realtime convolution with lots of