Filename: //usr/include//linux/sched//types.h

/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ #ifndef _LINUX_SCHED_TYPES_H #define _LINUX_SCHED_TYPES_H #include <linux/types.h> struct sched_param { int sched_priority; }; #define SCHED_ATTR_SIZE_VER0 48 /* sizeof first published struct */ #define SCHED_ATTR_SIZE_VER1 56 /* add: util_{min,max} */ /* * Extended scheduling parameters data structure. * * This is needed because the original struct sched_param can not be * altered without introducing ABI issues with legacy applications * (e.g., in sched_getparam()). * * However, the possibility of specifying more than just a priority for * the tasks may be useful for a wide variety of application fields, e.g., * multimedia, streaming, automation and control, and many others. * * This variant (sched_attr) allows to define additional attributes to * improve the scheduler knowledge about task requirements. * * Scheduling Class Attributes * =========================== * * A subset of sched_attr attributes specifies the * scheduling policy and relative POSIX attributes: * * @size size of the structure, for fwd/bwd compat. * * @sched_policy task's scheduling policy * @sched_nice task's nice value (SCHED_NORMAL/BATCH) * @sched_priority task's static priority (SCHED_FIFO/RR) * * Certain more advanced scheduling features can be controlled by a * predefined set of flags via the attribute: * * @sched_flags for customizing the scheduler behaviour * * Sporadic Time-Constrained Task Attributes * ========================================= * * A subset of sched_attr attributes allows to describe a so-called * sporadic time-constrained task. * * In such a model a task is specified by: * - the activation period or minimum instance inter-arrival time; * - the maximum (or average, depending on the actual scheduling * discipline) computation time of all instances, a.k.a. runtime; * - the deadline (relative to the actual activation time) of each * instance. * Very briefly, a periodic (sporadic) task asks for the execution of * some specific computation --which is typically called an instance-- * (at most) every period. Moreover, each instance typically lasts no more * than the runtime and must be completed by time instant t equal to * the instance activation time + the deadline. * * This is reflected by the following fields of the sched_attr structure: * * @sched_deadline representative of the task's deadline * @sched_runtime representative of the task's runtime * @sched_period representative of the task's period * * Given this task model, there are a multiplicity of scheduling algorithms * and policies, that can be used to ensure all the tasks will make their * timing constraints. * * As of now, the SCHED_DEADLINE policy (sched_dl scheduling class) is the * only user of this new interface. More information about the algorithm * available in the scheduling class file or in Documentation/. * * Task Utilization Attributes * =========================== * * A subset of sched_attr attributes allows to specify the utilization * expected for a task. These attributes allow to inform the scheduler about * the utilization boundaries within which it should schedule the task. These * boundaries are valuable hints to support scheduler decisions on both task * placement and frequency selection. * * @sched_util_min represents the minimum utilization * @sched_util_max represents the maximum utilization * * Utilization is a value in the range [0..SCHED_CAPACITY_SCALE]. It * represents the percentage of CPU time used by a task when running at the * maximum frequency on the highest capacity CPU of the system. For example, a * 20% utilization task is a task running for 2ms every 10ms at maximum * frequency. * * A task with a min utilization value bigger than 0 is more likely scheduled * on a CPU with a capacity big enough to fit the specified value. * A task with a max utilization value smaller than 1024 is more likely * scheduled on a CPU with no more capacity than the specified value. */ struct sched_attr { __u32 size; __u32 sched_policy; __u64 sched_flags; /* SCHED_NORMAL, SCHED_BATCH */ __s32 sched_nice; /* SCHED_FIFO, SCHED_RR */ __u32 sched_priority; /* SCHED_DEADLINE */ __u64 sched_runtime; __u64 sched_deadline; __u64 sched_period; /* Utilization hints */ __u32 sched_util_min; __u32 sched_util_max; }; #endif /* _LINUX_SCHED_TYPES_H */

./Ninja\.