![Dario Faggioli](/assets/img/avatar_default.png)
Some method to deal with rt-mutexes and make sched_dl interact with the current PI-coded is needed, raising all but trivial issues, that needs (according to us) to be solved with some restructuring of the pi-code (i.e., going toward a proxy execution-ish implementation). This is under development, in the meanwhile, as a temporary solution, what this commits does is: - ensure a pi-lock owner with waiters is never throttled down. Instead, when it runs out of runtime, it immediately gets replenished and it's deadline is postponed; - the scheduling parameters (relative deadline and default runtime) used for that replenishments --during the whole period it holds the pi-lock-- are the ones of the waiting task with earliest deadline. Acting this way, we provide some kind of boosting to the lock-owner, still by using the existing (actually, slightly modified by the previous commit) pi-architecture. We would stress the fact that this is only a surely needed, all but clean solution to the problem. In the end it's only a way to re-start discussion within the community. So, as always, comments, ideas, rants, etc.. are welcome! :-) Signed-off-by: Dario Faggioli <raistlin@linux.it> Signed-off-by: Juri Lelli <juri.lelli@gmail.com> [ Added !RT_MUTEXES build fix. ] Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1383831828-15501-11-git-send-email-juri.lelli@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
70 lines
1.8 KiB
C
70 lines
1.8 KiB
C
#ifndef _SCHED_RT_H
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#define _SCHED_RT_H
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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 + 40)
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#define DEFAULT_PRIO (MAX_RT_PRIO + 20)
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static inline int rt_prio(int prio)
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{
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if (unlikely(prio < MAX_RT_PRIO))
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return 1;
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return 0;
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}
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static inline int rt_task(struct task_struct *p)
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{
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return rt_prio(p->prio);
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}
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#ifdef CONFIG_RT_MUTEXES
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extern int rt_mutex_getprio(struct task_struct *p);
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extern void rt_mutex_setprio(struct task_struct *p, int prio);
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extern struct task_struct *rt_mutex_get_top_task(struct task_struct *task);
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extern void rt_mutex_adjust_pi(struct task_struct *p);
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static inline bool tsk_is_pi_blocked(struct task_struct *tsk)
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{
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return tsk->pi_blocked_on != NULL;
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}
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#else
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static inline int rt_mutex_getprio(struct task_struct *p)
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{
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return p->normal_prio;
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}
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static inline struct task_struct *rt_mutex_get_top_task(struct task_struct *task)
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{
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return NULL;
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}
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# define rt_mutex_adjust_pi(p) do { } while (0)
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static inline bool tsk_is_pi_blocked(struct task_struct *tsk)
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{
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return false;
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}
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#endif
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extern void normalize_rt_tasks(void);
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/*
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* default timeslice is 100 msecs (used only for SCHED_RR tasks).
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* Timeslices get refilled after they expire.
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*/
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#define RR_TIMESLICE (100 * HZ / 1000)
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#endif /* _SCHED_RT_H */
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