3ee237dddc
Currently there is lots of hard coding to 19 and -20, to represent maximum and minimum of nice values. This patch add three macros in prio.h for maximum, minimum and width of nice value, and uses it to remove hardcoded values in prio.h. Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/3994e89327b2b15f992277cdf9f409c516f87d1b.1392103744.git.yangds.fnst@cn.fujitsu.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ Collapsed two small patches. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
45 lines
1.4 KiB
C
45 lines
1.4 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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#endif /* _SCHED_PRIO_H */
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