USCHED(8)

NAME
usched - run a program with a specified userland scheduler and cpumask

SYNOPSIS
usched [-d] {scheduler[:cpumask] |:cpumask} program [argument ...]

DESCRIPTION
Run program using the specified userland scheduler on CPUs given in cpumask. It assigns the program to the CPU with the smallest cpuid and adds the rest of the CPUs to the list of available CPUs for the program. The userland scheduler can have value ‘bsd4’ or ‘dfly’. If scheduler is not specified, userland scheduler is inherited from parent process (usched).

The following options are available:

-d  Add debug output.

usched is only usable for super user as other users cannot change userland scheduler or cpumask.

System default userland scheduler can be changed in loader.conf(5), see loader(8).

EXIT STATUS

EXAMPLES
Run sh(1) using only first 3 CPUs.

    usched :7 sh

Run sh(1) using userland scheduler ‘bsd4’ using only first 4 CPUs.

    usched bsd4:0xf sh

SEE ALSO
usched_set(2), loader.conf(5), loader(8)

HISTORY
The usched utility first appeared in DragonFly 3.1.

AUTHORS
Matthew Dillon <dillon@backplane.com> Thomas Nikolajsen <thomas.nikolajsen@mail.dk>

BUGS
Using system default userland scheduler by specifying scheduler as ‘default’ is not implemented.

cpumask only supports up to 64 CPUs due to implementation of usched.