Personal computing discussed

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chuckula
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Re: Task Scheduling, PPID, forking, NUMA

Sun Jun 30, 2019 11:05 am

Point 1: Oh so you were running "numad" in the background? NICE TRY making us all run in circles while you pulled strings in the background ;-)

Point 2: On your performance "clustering" issue, there are plenty of possible culprits but here's a simple setting that might help: Make sure your CPU governor is set to "performance" instead of "ondemand" or "powersave". Most Linux distros default to "ondemand" to save a little power, but in your case you don't want all that extra logic complicating things. I'm not promising it will fix all your problems but at a minimum it shouldn't hurt.

Another point that's maybe so basic we haven't brought it up: What kernel version are you running? I highly recommend a very new kernel for a Threadripper since you can't expect perfection from a scheduler that was written before AMD threw the 2990 over the wall.
4770K @ 4.7 GHz; 32GB DDR3-2133; Officially RX-560... that's right AMD you shills!; 512GB 840 Pro (2x); Fractal Define XL-R2; NZXT Kraken-X60
--Many thanks to the TR Forum for advice in getting it built.
 
blastdoor
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Re: Task Scheduling, PPID, forking, NUMA

Mon Jul 01, 2019 8:44 am

As I continue to work on better understanding the performance characteristics of the 2990wx and how best to use this thing, I'm wondering if an article written on the subject might be of interest?

I'd be happy to donate such an article to the TR cause, if anybody thinks it might be of interest/value.
1. iMac 27" (2020) i7 10700k; AMD Radeon Pro 5500 XT 8 GB; 64 GB RAM; 500 GB internal SSD + external box of SSDs
2. ThreadRipper 2990wx; Ubuntu; Headless; 64GB RAM
3. MacBook Pro (2017); Core i7-7820HQ; 16 GB RAM
 
just brew it!
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Re: Task Scheduling, PPID, forking, NUMA

Mon Jul 01, 2019 8:57 am

I would read it.
Nostalgia isn't what it used to be.
 
blastdoor
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Re: Task Scheduling, PPID, forking, NUMA

Mon Jul 01, 2019 9:06 am

chuckula wrote:
Point 1: Oh so you were running "numad" in the background? NICE TRY making us all run in circles while you pulled strings in the background ;-)

Point 2: On your performance "clustering" issue, there are plenty of possible culprits but here's a simple setting that might help: Make sure your CPU governor is set to "performance" instead of "ondemand" or "powersave". Most Linux distros default to "ondemand" to save a little power, but in your case you don't want all that extra logic complicating things. I'm not promising it will fix all your problems but at a minimum it shouldn't hurt.

Another point that's maybe so basic we haven't brought it up: What kernel version are you running? I highly recommend a very new kernel for a Threadripper since you can't expect perfection from a scheduler that was written before AMD threw the 2990 over the wall.


Re point 1 --- sorry guys! I fully confess to massive stupidity on this one. It's a good example of why people like me ought to stick to Macs ;-)

Re point 2 --- thanks for the tip, I'll look into that!

Re point 2.5 -- 5.0.6-050006-generic
1. iMac 27" (2020) i7 10700k; AMD Radeon Pro 5500 XT 8 GB; 64 GB RAM; 500 GB internal SSD + external box of SSDs
2. ThreadRipper 2990wx; Ubuntu; Headless; 64GB RAM
3. MacBook Pro (2017); Core i7-7820HQ; 16 GB RAM
 
blastdoor
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Re: Task Scheduling, PPID, forking, NUMA

Mon Jul 01, 2019 2:21 pm

btw, Chuck -- I just ran a little comparison of my Threadripper system to my 2014 iMac (4 GHz 4790K)... unless I'm doing something stupid (which we all know is highly likely), this comparison of a 2018 Threadripper to a 2014 Haswell should make you very happy. It makes me wonder if the R packages I'm using for this particular task are using AVX2.
1. iMac 27" (2020) i7 10700k; AMD Radeon Pro 5500 XT 8 GB; 64 GB RAM; 500 GB internal SSD + external box of SSDs
2. ThreadRipper 2990wx; Ubuntu; Headless; 64GB RAM
3. MacBook Pro (2017); Core i7-7820HQ; 16 GB RAM
 
chuckula
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Joined: Wed Jan 23, 2008 9:18 pm
Location: Probably where I don't belong.

Re: Task Scheduling, PPID, forking, NUMA

Mon Jul 01, 2019 2:55 pm

blastdoor wrote:
btw, Chuck -- I just ran a little comparison of my Threadripper system to my 2014 iMac (4 GHz 4790K)... unless I'm doing something stupid (which we all know is highly likely), this comparison of a 2018 Threadripper to a 2014 Haswell should make you very happy. It makes me wonder if the R packages I'm using for this particular task are using AVX2.


This is the part where blastdoor realizes that those wackos at Intel didn't just dump all that effort into AVX for chuckula's forum posts. (But AVX-512 was 100% for the forum posts, let's be real here)
4770K @ 4.7 GHz; 32GB DDR3-2133; Officially RX-560... that's right AMD you shills!; 512GB 840 Pro (2x); Fractal Define XL-R2; NZXT Kraken-X60
--Many thanks to the TR Forum for advice in getting it built.
 
blastdoor
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Re: Task Scheduling, PPID, forking, NUMA

Mon Jul 01, 2019 8:32 pm

chuckula wrote:
blastdoor wrote:
btw, Chuck -- I just ran a little comparison of my Threadripper system to my 2014 iMac (4 GHz 4790K)... unless I'm doing something stupid (which we all know is highly likely), this comparison of a 2018 Threadripper to a 2014 Haswell should make you very happy. It makes me wonder if the R packages I'm using for this particular task are using AVX2.


This is the part where blastdoor realizes that those wackos at Intel didn't just dump all that effort into AVX for chuckula's forum posts. (But AVX-512 was 100% for the forum posts, let's be real here)


I guess I have a chip on my shoulder regarding vector units from altivec G4 days. I know they can make a big difference *sometimes* but I take it as a bad sign when people place a lot of emphasis on it. But maybe that’s not a fair comparison— the G4 was an unbalanced design. Intels designs are very well balanced.
1. iMac 27" (2020) i7 10700k; AMD Radeon Pro 5500 XT 8 GB; 64 GB RAM; 500 GB internal SSD + external box of SSDs
2. ThreadRipper 2990wx; Ubuntu; Headless; 64GB RAM
3. MacBook Pro (2017); Core i7-7820HQ; 16 GB RAM
 
just brew it!
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Re: Task Scheduling, PPID, forking, NUMA

Mon Jul 01, 2019 10:38 pm

Yeah, this ain't your father's vector unit. :wink:

Now that AVX and AVX2 are widely available, with AVX-512 to become mainstream eventually as well, leveraging it where appropriate should become the norm.
Nostalgia isn't what it used to be.

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