Scheduler Improvements Published For The Linux 4.6 Kernel

[phoronix]

Phoronix: Scheduler Improvements Published For The Linux 4.6 Kernel

Ingo Molnar is once again very punctual with sending his pull requests in right away for the next Linux kernel merge window for the numerous areas he oversees as the maintainer. One of his interesting pull requests this morning is of the scheduler updates...

http://www.phoronix.com/scan.php?page=news_item&px=Linux-4.6-Scheduler

[dimko]

I wonder, if any of those improvements can make Desktop/gaming experience more fluid?
BFS is nice, but I we need something that is in the kernel...

[tessio]

My Linux Mint 17.3 uses 760MB from the 3072MB available, so memory is not the problem. But every time I'm writing a big file to a disk (internal o external) everything becomes super slow, even the mouse pointer movement start to hang. Is this a scheduler thing? Anyone else experience that? This deadline scheduler could help?


**Edit**
It turns out that I'm already using the deadline scheduler:

$ cat /sys/block/sda/queue/scheduler
noop [deadline] cfq

[bug77]

I wonder, if any of those improvements can make Desktop/gaming experience more fluid?
BFS is nice, but I we need something that is in the kernel...

I don't expect these changes to have any visible effect unless we're talking hundreds or thousands of threads.

[sarfarazahmad]

I don't expect these changes to have any visible effect unless we're talking hundreds or thousands of threads.

i run BFQ on a shitty old laptop. old hdd doesnt give more than 25MBps on a disk to disk transfer on a sata 2 bus. if i run ubuntu on it, the same stuff happens thats mentioned above. BFQ is far more pleasant.

[dimko]

I don't expect these changes to have any visible effect unless we're talking hundreds or thousands of threads.

thanks for the info.

[dimko]

My Linux Mint 17.3 uses 760MB from the 3072MB available, so memory is not the problem. But every time I'm writing a big file to a disk (internal o external) everything becomes super slow, even the mouse pointer movement start to hang. Is this a scheduler thing? Anyone else experience that? This deadline scheduler could help?


**Edit**
It turns out that I'm already using the deadline scheduler:

$ cat /sys/block/sda/queue/scheduler
noop [deadline] cfq

There is also I/O scheduler, which is not related to CPU. There is also memory tweak available in the /proc/ file system.
First can prioritize process of writing to HDD/SDD, second can control dirty caching, etc. I am not at home so can't throw in the links. Sound like memory tweaking can do some good to you.
Also, clarify size of file + it's source + where you read it from and where you write it from.

Ideally, open up new thread about it.

[cynic]

My Linux Mint 17.3 uses 760MB from the 3072MB available, so memory is not the problem. But every time I'm writing a big file to a disk (internal o external) everything becomes super slow, even the mouse pointer movement start to hang. Is this a scheduler thing? Anyone else experience that? This deadline scheduler could help?


**Edit**
It turns out that I'm already using the deadline scheduler:

$ cat /sys/block/sda/queue/scheduler
noop [deadline] cfq

I'd suggest you to take a look at this (if you already didn't)

http://algo.ing.unimo.it/people/paolo/disk_sched/description.php

some says that for some workloads they get worse performance, but surely from the user standpoint the system feels much more fluid even under heavy disk I/O.

[c117152]

Oh good some scheduler love. I've also been having system wide freezes with NCQ on over intensive disk I/O where the system becomes unresponsive while long write operations are ongoing.
I always assumes the guy responsible for the scheduling work is some impoverished student working through his dissertation while running a 10 year old 500GB 5600RPM HDD that has slow enough write speeds that he never needs to put in locks

[cl333r]

My Linux Mint 17.3 uses 760MB from the 3072MB available, so memory is not the problem. But every time I'm writing a big file to a disk (internal o external) everything becomes super slow, even the mouse pointer movement start to hang. Is this a scheduler thing? Anyone else experience that? This deadline scheduler could help?


**Edit**
It turns out that I'm already using the deadline scheduler:

$ cat /sys/block/sda/queue/scheduler
noop [deadline] cfq

Afaik there's a CPU scheduler and a I/O scheduler, your (and mine) issue is with the latter. I'm using BFQ, much better so far than CFQ.

http://lwn.net/Articles/601799/

http://lwn.net/Articles/674308/