Viewing file:  ioprio.h (1.44 KB) -rw-r--r--
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/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
#ifndef _UAPI_LINUX_IOPRIO_H
#define _UAPI_LINUX_IOPRIO_H
/*
* Gives us 8 prio classes with 13-bits of data for each class
*/
#define IOPRIO_CLASS_SHIFT 13
#define IOPRIO_CLASS_MASK 0x07
#define IOPRIO_PRIO_MASK ((1UL << IOPRIO_CLASS_SHIFT) - 1)
#define IOPRIO_PRIO_CLASS(ioprio) \
(((ioprio) >> IOPRIO_CLASS_SHIFT) & IOPRIO_CLASS_MASK)
#define IOPRIO_PRIO_DATA(ioprio) ((ioprio) & IOPRIO_PRIO_MASK)
#define IOPRIO_PRIO_VALUE(class, data) \
((((class) & IOPRIO_CLASS_MASK) << IOPRIO_CLASS_SHIFT) | \
((data) & IOPRIO_PRIO_MASK))
/*
* These are the io priority groups as implemented by the BFQ and mq-deadline
* schedulers. RT is the realtime class, it always gets premium service. For
* ATA disks supporting NCQ IO priority, RT class IOs will be processed using
* high priority NCQ commands. BE is the best-effort scheduling class, the
* default for any process. IDLE is the idle scheduling class, it is only
* served when no one else is using the disk.
*/
enum {
IOPRIO_CLASS_NONE,
IOPRIO_CLASS_RT,
IOPRIO_CLASS_BE,
IOPRIO_CLASS_IDLE,
};
/*
* The RT and BE priority classes both support up to 8 priority levels.
*/
#define IOPRIO_NR_LEVELS 8
#define IOPRIO_BE_NR IOPRIO_NR_LEVELS
enum {
IOPRIO_WHO_PROCESS = 1,
IOPRIO_WHO_PGRP,
IOPRIO_WHO_USER,
};
/*
* Fallback BE priority level.
*/
#define IOPRIO_NORM 4
#define IOPRIO_BE_NORM IOPRIO_NORM
#endif /* _UAPI_LINUX_IOPRIO_H */
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