profile - scheduling configuration
A profile allows a set of high level scheduling priorities to be defined and later applied to one or more threads. Each profile object defines a scheduling configuration (though currently only thread priority is implemented). Once created, the profile can be applied to one or more threads, which will then adopt those settings.
Profile objects define a high level scheduling policy that can be applied to threads. For example, an "audio processing" profile could be created with a high scheduling priority, and then be applied to threads in media playback jobs. Alternatively, a "background" profile could be created with a low scheduling priority, and then be applied to threads in non-interactive jobs.
Policy objects are created with the
zx_profile_create() syscall, passing in
a scheduling configuration. The returned profile may then be applied to one or
more threads using the
Because profiles give significant control of the behaviour of the kernel scheduler, creating a profile requires the root resource. Once created, profiles may be delegated freely, however.
Currently, only a single scheduler parameter
scheduler.priority is supported,
which determines the priority of the thread used by Zircon's kernel
zx_profile_create() describes how to
construct a profile object with a custom scheduler priority.