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kern.sched.preempt_thresh

Posted: Fri Jan 31, 2020 8:25 am
by RoboNuggie
Hi, I was wondering if there was a technical reason why kern.sched.preempt_thresh=224
wasn't included in the sysctl.conf and that the system is default 80, which is great for servers, but perhaps not optimum for
desktop use..... it is one of the first things I change when setting up a FreeBSD desktop -
for a server, I leave it at 80, but desktop it's a must for me....

Thanks.....

Re: kern.sched.preempt_thresh

Posted: Fri Jan 31, 2020 8:30 am
by RoboNuggie
oops, sorry if I posted in the wrong section....

Re: kern.sched.preempt_thresh

Posted: Fri Jan 31, 2020 9:03 am
by ericbsd
There is no reason that is at 80, I never changed that before, I did look into it and I will add this in the future release and maybe by default since I manage the source code to build the system.

Re: kern.sched.preempt_thresh

Posted: Fri Jan 31, 2020 9:38 am
by RoboNuggie
Thank you Eric, you are a star.... I don't foresee any problems, and I'm doing a review of 20.01 now, using it exclusively for a week - I put in the tweak and it runs without any issues as a desktop with it....

Re: kern.sched.preempt_thresh

Posted: Fri Jan 31, 2020 9:48 am
by ericbsd
I have added it in the default source code I will probably build a new system package with it this change soon.

kern.sched.preempt_thresh: 48

Posted: Tue Sep 27, 2022 5:24 pm
by grahamperrin
RoboNuggie wrote: Fri Jan 31, 2020 8:25 am … the system is default 80, …
Not so here with FreeBSD 14.0-CURRENT.

Code: Select all

% sysctl kern.sched.preempt_thresh
kern.sched.preempt_thresh: 48
% date ; uname -aKU
Tue 27 Sep 2022 21:22:26 BST
FreeBSD mowa219-gjp4-8570p-freebsd 14.0-CURRENT FreeBSD 14.0-CURRENT #21 main-n258027-c9baa974717a: Fri Sep 16 15:41:27 BST 2022     grahamperrin@mowa219-gjp4-8570p-freebsd:/usr/obj/usr/src/amd64.amd64/sys/GENERIC-NODEBUG amd64 1400067 1400067
% grep kern.sched.preempt_thresh /etc/sysctl.conf | grep -v \#
%