98 lines
2.1 KiB
C
98 lines
2.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef IOPRIO_H
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#define IOPRIO_H
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#include <linux/sched.h>
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#include <linux/sched/rt.h>
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#include <linux/iocontext.h>
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#include <uapi/linux/ioprio.h>
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/*
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* Default IO priority.
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*/
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#define IOPRIO_DEFAULT IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 0)
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/*
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* Check that a priority value has a valid class.
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*/
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static inline bool ioprio_valid(unsigned short ioprio)
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{
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unsigned short class = IOPRIO_PRIO_CLASS(ioprio);
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return class > IOPRIO_CLASS_NONE && class <= IOPRIO_CLASS_IDLE;
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}
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/*
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* if process has set io priority explicitly, use that. if not, convert
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* the cpu scheduler nice value to an io priority
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*/
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static inline int task_nice_ioprio(struct task_struct *task)
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{
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return (task_nice(task) + 20) / 5;
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}
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/*
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* This is for the case where the task hasn't asked for a specific IO class.
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* Check for idle and rt task process, and return appropriate IO class.
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*/
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static inline int task_nice_ioclass(struct task_struct *task)
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{
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if (task->policy == SCHED_IDLE)
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return IOPRIO_CLASS_IDLE;
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else if (rt_or_dl_task_policy(task))
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return IOPRIO_CLASS_RT;
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else
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return IOPRIO_CLASS_BE;
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}
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#ifdef CONFIG_BLOCK
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/*
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* If the task has set an I/O priority, use that. Otherwise, return
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* the default I/O priority.
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*
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* Expected to be called for current task or with task_lock() held to keep
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* io_context stable.
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*/
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static inline int __get_task_ioprio(struct task_struct *p)
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{
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struct io_context *ioc = p->io_context;
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int prio;
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if (!ioc)
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return IOPRIO_DEFAULT;
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if (p != current)
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lockdep_assert_held(&p->alloc_lock);
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prio = ioc->ioprio;
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if (IOPRIO_PRIO_CLASS(prio) == IOPRIO_CLASS_NONE)
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prio = IOPRIO_PRIO_VALUE(task_nice_ioclass(p),
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task_nice_ioprio(p));
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return prio;
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}
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#else
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static inline int __get_task_ioprio(struct task_struct *p)
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{
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return IOPRIO_DEFAULT;
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}
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#endif /* CONFIG_BLOCK */
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static inline int get_current_ioprio(void)
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{
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return __get_task_ioprio(current);
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}
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extern int set_task_ioprio(struct task_struct *task, int ioprio);
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#ifdef CONFIG_BLOCK
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extern int ioprio_check_cap(int ioprio);
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#else
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static inline int ioprio_check_cap(int ioprio)
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{
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return -ENOTBLK;
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}
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#endif /* CONFIG_BLOCK */
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#endif
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