60 lines
1.7 KiB
C
60 lines
1.7 KiB
C
#ifndef _SCHED_PRIO_H
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#define _SCHED_PRIO_H
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#define MAX_NICE 19
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#define MIN_NICE -20
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#define NICE_WIDTH (MAX_NICE - MIN_NICE + 1)
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/*
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* Priority of a process goes from 0..MAX_PRIO-1, valid RT
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* priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
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* tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
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* values are inverted: lower p->prio value means higher priority.
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*
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* The MAX_USER_RT_PRIO value allows the actual maximum
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* RT priority to be separate from the value exported to
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* user-space. This allows kernel threads to set their
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* priority to a value higher than any user task. Note:
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* MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
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*/
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#define MAX_USER_RT_PRIO 100
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#define MAX_RT_PRIO MAX_USER_RT_PRIO
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#define MAX_PRIO (MAX_RT_PRIO + NICE_WIDTH)
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#define DEFAULT_PRIO (MAX_RT_PRIO + NICE_WIDTH / 2)
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/*
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* Convert user-nice values [ -20 ... 0 ... 19 ]
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* to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
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* and back.
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*/
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#define NICE_TO_PRIO(nice) ((nice) + DEFAULT_PRIO)
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#define PRIO_TO_NICE(prio) ((prio) - DEFAULT_PRIO)
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/*
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* 'User priority' is the nice value converted to something we
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* can work with better when scaling various scheduler parameters,
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* it's a [ 0 ... 39 ] range.
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*/
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#define USER_PRIO(p) ((p)-MAX_RT_PRIO)
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#define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio)
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#define MAX_USER_PRIO (USER_PRIO(MAX_PRIO))
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/*
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* Convert nice value [19,-20] to rlimit style value [1,40].
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*/
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static inline long nice_to_rlimit(long nice)
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{
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return (MAX_NICE - nice + 1);
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}
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/*
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* Convert rlimit style value [1,40] to nice value [-20, 19].
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*/
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static inline long rlimit_to_nice(long prio)
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{
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return (MAX_NICE - prio + 1);
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}
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#endif /* _SCHED_PRIO_H */
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