Automatic set affinity for single-thread process. Possible?

[msg7086]

Hi all

I'm experiencing bad performance on a hex-core system while running a single threaded process.

I'd hope that Process Lasso can automatically assign a CPU core for such process (either manually, or by auto-detect, i.e. 16.6% on a hex-core, or 25% on a quad-core)

As far as I can see, the only thing I can do is to set a default affinity for such process.

But sometimes I'd like to run several instances of one process, each takes 16%. Simply set them to the same core is not a good choice for me.

I wonder if it can balance them into different low-load single core automatically.

Thank you.

[BenYeeHua]

So just running each process with difference user name, and create the watchdog as "processname:username"
http://bitsum.com/forum/index.php/topic,1923.msg9084.html#msg9084

[msg7086]

Thanks for the idea

In my case, if I can run a  process with different users, I actually can specify affinity when starting that process, by using "start /affinity:X command".

What I'm looking for, is a watchdog rule for affinity, only that the operation is not "set affinity to CPU core 3 & 4", but "set affinity to any one (or two) low-load core"

[BenYeeHua]

Oh, so I has no idea for that.
It seen like you has running more than 6 process that using the 6 core, but sometimes some of them will bit the core too much.
So you wanna the other process allocate to other core that having low load automatic by PL.

[msg7086]

Well, the actual reason to do this is because sticking to a single core makes a single-thread process running much faster.

For example, you convert a music into mp3 using lame, on a hex-core computer.
If there's no affinity limit, lame.exe will use all 6 cores to run a single thread. The OS will assign 16% of each core time slices to the process, and the process will be rapidly switching among the 6 cores.
Switching among cores will lead to high overhead such as lost of cache and time to switch cpu context.

Force a single-thread process on a specific core will prevent this stupid CPU time schedule, and it will run faster.

In my computer, it'll be 2x~3x speed up.

[BenYeeHua]

Ya, but after you set affinity for the process, like core 0.
The OS will prevent other processes on that core, except you set the other processes with the same affinity.
So it means that, if the core 0 is using 80% by other processes that with all affinity tick(default).
After you set affinity on other process, it will be moved to other core.

Can I know which processor are you using?
Because I has test on the i3-2330M(laptop), it only loss 1-2% if I don't set the affinity.
Maybe with help of the low delay L2.

prevent this stupid CPU time schedule

Did you try disable Core-Parking?
It also reduce the time to schedule also.
Except you are using older than Windows Vista.

[Jeremy Collake]

Explore the watchdog options and if none meet your needs a custom feature may be required. I was ill for a couple days so am just getting caught up, but can explore alternate solutions too. I will need to read through this more carefully, I may have another idea. BenYeeHua also gave good advice.

[msg7086]

Ya, but after you set affinity for the process, like core 0.
The OS will prevent other processes on that core, except you set the other processes with the same affinity.
So it means that, if the core 0 is using 80% by other processes that with all affinity tick(default).
After you set affinity on other process, it will be moved to other core.

Can I know which processor are you using?
Because I has test on the i3-2330M(laptop), it only loss 1-2% if I don't set the affinity.
Maybe with help of the low delay L2.Did you try disable Core-Parking?
It also reduce the time to schedule also.
Except you are using older than Windows Vista.

I'm on a AMD 1090T which is 6 core 6 threads. And things can be worse on my server which is dual 2620, 12c 24t.
Switching between 2 cores may not consume that much overhead, but with a 6 core CPU (or with 12+ cores) it could be a problem.
(or it's AMD's fault?)

I played around the core-parking and problem didn't solved. I also set the power options to max performance, no good.

And I'm on the new Server 2012, which is Win8 server.

Explore the watchdog options and if none meet your needs a custom feature may be required. I was ill for a couple days so am just getting caught up, but can explore alternate solutions too. I will need to read through this more carefully, I may have another idea. BenYeeHua also gave good advice.

I've checked the watchdog rules. And the options after 'then:' includes 'change CPU affinity' but you can only choose a specific value instead of a random / spare core depends on actual CPU usage.

And take care

[BenYeeHua]

Ya, but most people that I meet are converting and converting and gaming, so they are not facing the same problem.
The only thing that I can think is manual set affinity for each process, as maybe there are no software that can meet your request for now.

[Jeremy Collake]

There are actually some undocumented features already in place that may assist you. One is typing in 'random' for the CPU affinity... this will self 1/2 of available cores.

[Jeremy Collake]

(updated last post to indicate that 'random' as an affinity will end up selecting 1/2 of available cores, at random) ... may not be exactly what you need, but just so you and others know that is there. I threw that in as a custom request for a user, and can do something similar for you, though I may ask for a small donation to compensate for the time and work. I mean small