A New BFS "Smoking" Scheduler For Linux 3.3

[Paradox Uncreated]

You've posted a config for a 2.6.39 generic kernel;

# Automatically generated make config: don't edit
# Linux/x86_64 2.6.39 Kernel Configuration
# Sat May 21 00:45:30 2011

This generic kernel would not perform as well as the same kernel using the BFS patch set (not on either of my Core2duo's, and not on my AMD Phenom II 965 x4). 2.6.39 was just before linux-rt-3.0 came out. For the entire time between 2.6.33-rt and 3.0.1-rt -> i was using BFS kernels, as i had some hardware that didn't play nice with 2.6.33-rt - and subsequently ended up using BFS on all my systems, because it worked noticably betterthan CFS on the same kernel, during that period. On all machines (using 2.6.39, when it came out) BFS ran smoother / more stable & reliably for proaudio then CFS, and that's with using the 'threaded irq' boot parameter, that had been merged into mainline 2.6.39, from the -rt patches ... I tested this quite a bit at the time.

I currently use RT-kernels, but BFS is definitely a great alternative to CFS for certain workloads. I would likely be using it right now, if RT wasn't an option, or if I thought it was overkill for my usage.

To say, Con is wasting his time - as you've said before, is silly. Lots of people have been using BFS for years, in my own experiences, it was great and in situations where i was getting XRUNS with CFS (on any kernel 2.6.33+) - with BFS, they didn't exist (on several machines). I think both CFS and BFS have value, and it's healthy to have them both around.

my 2 cents

Lol, I don`t know what is going on here. I am not lying to you. Maybe you did use BFS in a time where it DID perform better. But it doesn`t anymore. Maybe that is the mindset you are used to, and fail to understand that I have been running low latencies, since atleast 2.6.36 I think.

You even have the same CPU as me. Seriously if you are using RT kernels anymore.. I don`t know, that just seems way overkill for normal audio. Usually you won`t need latencies below 5ms. If your speakers are a bit far away, you can always try to lower it. The thing is though, if you have fine granularity multitasking, everything runs smooth. And is responsive. Even without RT threads, 0.33 ms worked, not as good as with RT threads, but quite good. Meaning that the whole system is very smooth now. So yes, common applications should run very smoothly, but you do need the config for doing that. General idea of my config is to avoid components that do uneccesary things for me. So that I avoid stalls, that prevent low latencies. That could be memory compaction or similar things. Or I can`t really remember all the stuff I tweaked in the end. It was running smoothly and greatly though, and I remember thinking Linux has reached that stage. Kind of a dream for many computer enthusiasts to have a system that performs that well. Forget about your vintage computing systems, and all the cries of them being more responsive. Now you have a modern system, that has the benefits of both responsiveness, and highlevel programming.

Peeeeeeeeeeeeeeeeeeeeace. zzZ

[jwilliams]

This is a kernelconfig for 0.33 ms latency. http://www.paradoxuncreated.com/tmp/.config39

# CONFIG_HZ_100 is not set
# CONFIG_HZ_250 is not set
# CONFIG_HZ_300 is not set
CONFIG_HZ_1000=y
CONFIG_HZ=1000

[ninez]

Lol, I don`t know what is going on here. I am not lying to you. Maybe you did use BFS in a time where it DID perform better. But it doesn`t anymore. Maybe that is the mindset you are used to, and fail to understand that I have been running low latencies, since atleast 2.6.36 I think.

You do realize this isn't RealNC, right? I just saw your post with the 'generic' 2.6.39 .config, and found it kind of funny, that you think BFS is garbage (and rant about it), when i have tested it on lots of systems, and it worked great - better than a generic CFS kernel... As for it not being good anymore, that may be true, but i see one problem with your logic, you list a config for 2.6.39 ~ which isn't 'now' that kernel is an old one, not a 'current' kernel. i don't know if BFS is behaving poorly these days and i probably wouldn't just take your word for it.

You even have the same CPU as me.

yeah, i have 4 machines (actually 7 that i 'could use) to test against versus 'just' your one dual-core, which do you think is a broader test, one machine or four? I would tend to think it is better to test across many machines... You seem to think only your one little machine matters....and by the way what model of (Intel?) dualcore do you have, because i do in fact have an Intel dual-core kicking around. and Honestly, not having the same CPU doesn't mean all that much ~ your hardware might just be a corner case, where you are getting nice results, as that does happen sometimes.

Seriously if you are using RT kernels anymore.. I don`t know, that just seems way overkill for normal audio. Usually you won`t need latencies below 5ms. If your speakers are a bit far away, you can always try to lower it.

I'm a musician and play live with my gear, lower latencies is better and RT is *ideal*. I don't consider running dozens of synths, live inputs, looping, FX processing, etc + 8in/8out to be 'normal audio'. I usually sit around 1-2ms, unless i am just doing post production, where i will use larger buffers/frames, because mixing does not require low-latency, while playing does.

The thing is though, if you have fine granularity multitasking, everything runs smooth. And is responsive. Even without RT threads, 0.33 ms worked, not as good as with RT threads, but quite good. Meaning that the whole system is very smooth now. So yes, common applications should run very smoothly, but you do need the config for doing that. General idea of my config is to avoid components that do uneccesary things for me. So that I avoid stalls, that prevent low latencies. That could be memory compaction or similar things. Or I can`t really remember all the stuff I tweaked in the end. It was running smoothly and greatly though, and I remember thinking Linux has reached that stage. Kind of a dream for many computer enthusiasts to have a system that performs that well. Forget about your vintage computing systems, and all the cries of them being more responsive. Now you have a modern system, that has the benefits of both responsiveness, and highlevel programming.

"

In linux, how many proaudio applications are you using that don't require RT-scheduling?

You'll have to elaborate on "General idea of my config is to avoid components that do uneccesary things for me", i disable everything in the kernel config that doesn't apply to my hardware, and *only* enable features that i require. I also avoid running daemons & software that isn't needed... As for avoiding stalls that prevent low latencies, doesn't it actually make more sense to do what i've said above and then also tuning stuff in /proc/sys/kernel and/or specifying those changes in /etc/sysctl.conf, once you have tested the changes and seen valid improvments in latency??

cheerz

[ninez]

# CONFIG_HZ_100 is not set
# CONFIG_HZ_250 is not set
# CONFIG_HZ_300 is not set
CONFIG_HZ_1000=y
CONFIG_HZ=1000

IMO most Linux 'Desktop' type machines should probably have that in the config, that isn't really anything special. Just like most 'desktop' kernels should probably be PREEMPT, ideally.

cheerz

[Paradox Uncreated]

You do realize this isn't RealNC, right? I just saw your post with the 'generic' 2.6.39 .config, and found it kind of funny, that you think BFS is garbage (and rant about it), when i have tested it on lots of systems, and it worked great - better than a generic CFS kernel... As for it not being good anymore, that may be true, but i see one problem with your logic, you list a config for 2.6.39 ~ which isn't 'now' that kernel is an old one, not a 'current' kernel. i don't know if BFS is behaving poorly these days and i probably wouldn't just take your word for it.



yeah, i have 4 machines (actually 7 that i 'could use) to test against versus 'just' your one dual-core, which do you think is a broader test, one machine or four? I would tend to think it is better to test across many machines... You seem to think only your one little machine matters....and by the way what model of (Intel?) dualcore do you have, because i do in fact have an Intel dual-core kicking around. and Honestly, not having the same CPU doesn't mean all that much ~ your hardware might just be a corner case, where you are getting nice results, as that does happen sometimes.



I'm a musician and play live with my gear, lower latencies is better and RT is *ideal*. I don't consider running dozens of synths, live inputs, looping, FX processing, etc + 8in/8out to be 'normal audio'. I usually sit around 1-2ms, unless i am just doing post production, where i will use larger buffers/frames, because mixing does not require low-latency, while playing does.

"

In linux, how many proaudio applications are you using that don't require RT-scheduling?

You'll have to elaborate on "General idea of my config is to avoid components that do uneccesary things for me", i disable everything in the kernel config that doesn't apply to my hardware, and *only* enable features that i require. I also avoid running daemons & software that isn't needed... As for avoiding stalls that prevent low latencies, doesn't it actually make more sense to do what i've said above and then also tuning stuff in /proc/sys/kernel and/or specifying those changes in /etc/sysctl.conf, once you have tested the changes and seen valid improvments in latency??

cheerz

Cheerz.. Yeah I did notice the nick was different. Maybe you are just barking mad, and have two logins. So you can make the impression of having friends, and being a factor of internet opinion-power. You use the word "rant". I mean it has been used by many, I know. And your mind has probably picked it up, and smeared it into lots of random linux tidbits. That doesn`t make them right. And the idea that linux somehow should need disabling daemons and software, is completely wrong. It is some thing from 10 year old windows versions or something.

One thing is sure. Internet fanboys are also found in the linux-scene. And do not offend their gods, lest they strike you down. Now I am sure you would rather be performing private procedures on Con, than talk to me, so bye for now.

And btw, if RealNC insists I can make an exception for him, and greet him with "sledgehammer to the head" instead. I guess that will make all these amusementpark animals happy.

[ninez]

Cheerz.. Yeah I did notice the nick was different. Maybe you are just barking mad, and have two logins. So you can make the impression of having friends, and being a factor of internet opinion-power. You use the word "rant". I mean it has been used by many, I know. And your mind has probably picked it up, and smeared it into lots of random linux tidbits. That doesn`t make them right. And the idea that linux somehow should need disabling daemons and software, is completely wrong. It is some thing from 10 year old windows versions or something.

Barking mad? WTF are you even talking about, really?? i thought this was just a chill discussion, but now your making assumptions about my state of mind, insinuating that i am in fact RealNC, using 2 accounts on Phoronix and that a bunch of other BS. I said you rant, because your many posts would seem to add up to that, there was no 'insult' intended, at all. Definition of rant;

"to talk in a noisy, excited, or declamatory manner". ~ it seems like an accurate description to me. In particular in your last 2 posts.

As far disabling services, daemons, etc AFAIK it is still valid in win7 and is valid in Linux too. why waste cpu-cycles on things you don't need? it actually makes far more sense to do that, then to leave useless crap enabled. That is just common sense, and it's not a question of 'having/needing to disable stuff', it is a matter of doing it because it is beneficial....and in the case of disabling stuff in the kernel it reduces kernel bloat, and speeds up compilation times, very significantly. as for software/daemons - If i am not using bluetooth - then it should be disabled, as one small example. - So are you saying that i am wrong to think disabling crap that isn't needed is a bad idea? - if so, that is pretty stupid on your part.

One thing is sure. Internet fanboys are also found in the linux-scene. And do not offend their gods, lest they strike you down. Now I am sure you would rather be performing private procedures on Con, than talk to me, so bye for now.

And btw, if RealNC insists I can make an exception for him, and greet him with "sledgehammer to the head" instead. I guess that will make all these amusementpark animals happy.

total off topic rant, and i don't care. and what a last resort pathetic attempt at an insult. What a laughable joke, you come across as.

cheerz

[Paradox Uncreated]

Barking mad? WTF are you even talking about, really?? i thought this was just a chill discussion, but now your making assumptions about my state of mind, insinuating that i am in fact RealNC, using 2 accounts on Phoronix and that a bunch of other BS. I said you rant, because your many posts would seem to add up to that, there was no 'insult' intended, at all.

As far disabling services, daemons, etc AFAIK it is still valid in win7 and is valid in Linux too. why waste cpu-cycles on things you don't need? it actually makes far more sense to do that, then to leave useless crap enabled. That is just common sense. If i am not using bluetooth - then it should be disabled, as one small example. - So are you saying that i am wrong to think disabling crap that isn't needed is a bad idea? - if so, that is pretty stupid on your part.



total off topic rant, and i don't care.

cheerz

You are hysterical and no doubt an enthusiastic tweaker. But like many, who hear beauty in analog distortion, or think Ports of Call on amiga500 still can`t be beaten, it`s obscure rubbish.

Peace, or what greeting would you like, maybe The Tweak Be With You?

[ninez]

You are hysterical and no doubt an enthusiastic tweaker. But like many, who hear beauty in analog distortion, or think Ports of Call on amiga500 still can`t be beaten, it`s obscure rubbish.

analog gear does sound great, and typically much warmer than digital (that's a well-known FACT) and i don't play video games. so no cigar.
As for being a 'hyterical enthusiastic tweaker' ~ seriously dude, you have your pretentious little head rammed so far up your ass, all i can do is laugh at you, at this point. WTF are you even going on about? oh ya, i forgot this is a prime example of your 'ranting'.

Peace, or what greeting would you like, maybe The Tweak Be With You?

you're just trolling, and clearly it is you who is hyterical - i'm just logged into work, relaxing, getting a few things done before tomorrow,

nice try though, it's pretty obvious at this point that you are just trolling. You really haven't said anything relevant to this post in your last few posts, and didn't even bother to reply to most of what i have said.
grow up.

[Paradox Uncreated]

I am wondering, are these people told these things, and then echo some of that back?
Tweaks, attitude, and cliches.

I am a person sitting here. We are communicating on the internet. Because I am a person, and you are a person, I greet you in peace. That is a very nice thing to do, once all these ideas about tweaking and clicheed retorts are gone.

You should really try that.

Peace..

[ninez]

I am wondering, are these people told these things, and then echo some of that back?
Tweaks, attitude, and cliches.

I am a person sitting here. We are communicating on the internet. Because I am a person, and you are a person, I greet you in peace. That is a very nice thing to do, once all these ideas about tweaking and clicheed retorts are gone.

You should really try that.

Peace..

dude, those who treat others with disrepect should NOT expect it back. Sorry, if your feelings are hurt, but i don't care.

and just because you write 'peace' at the bottom of each message doesn't mean anything, as the rest of your post is usually pretty brutal and ignorant.

and if you want me to greet you with peace, i suggest not being an asshole in your posts.