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e70344c059
The default IO priority is the best effort (BE) class with the normal priority level IOPRIO_NORM (4). However, get_task_ioprio() returns IOPRIO_CLASS_NONE/IOPRIO_NORM as the default priority and get_current_ioprio() returns IOPRIO_CLASS_NONE/0. Let's be consistent with the defined default and have both of these functions return the default priority IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_NORM) when the user did not define another default IO priority for the task. In include/uapi/linux/ioprio.h, introduce the IOPRIO_BE_NORM macro as an alias to IOPRIO_NORM to clarify that this default level applies to the BE priotity class. In include/linux/ioprio.h, define the macro IOPRIO_DEFAULT as IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_BE_NORM) and use this new macro when setting a priority to the default. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Link: https://lore.kernel.org/r/20210811033702.368488-7-damien.lemoal@wdc.com [axboe: drop unnecessary lightnvm change] Signed-off-by: Jens Axboe <axboe@kernel.dk>
52 lines
1.4 KiB
C
52 lines
1.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
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#ifndef _UAPI_LINUX_IOPRIO_H
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#define _UAPI_LINUX_IOPRIO_H
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/*
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* Gives us 8 prio classes with 13-bits of data for each class
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*/
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#define IOPRIO_CLASS_SHIFT 13
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#define IOPRIO_CLASS_MASK 0x07
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#define IOPRIO_PRIO_MASK ((1UL << IOPRIO_CLASS_SHIFT) - 1)
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#define IOPRIO_PRIO_CLASS(ioprio) \
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(((ioprio) >> IOPRIO_CLASS_SHIFT) & IOPRIO_CLASS_MASK)
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#define IOPRIO_PRIO_DATA(ioprio) ((ioprio) & IOPRIO_PRIO_MASK)
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#define IOPRIO_PRIO_VALUE(class, data) \
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((((class) & IOPRIO_CLASS_MASK) << IOPRIO_CLASS_SHIFT) | \
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((data) & IOPRIO_PRIO_MASK))
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/*
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* These are the io priority groups as implemented by the BFQ and mq-deadline
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* schedulers. RT is the realtime class, it always gets premium service. For
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* ATA disks supporting NCQ IO priority, RT class IOs will be processed using
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* high priority NCQ commands. BE is the best-effort scheduling class, the
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* default for any process. IDLE is the idle scheduling class, it is only
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* served when no one else is using the disk.
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*/
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enum {
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IOPRIO_CLASS_NONE,
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IOPRIO_CLASS_RT,
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IOPRIO_CLASS_BE,
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IOPRIO_CLASS_IDLE,
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};
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/*
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* The RT and BE priority classes both support up to 8 priority levels.
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*/
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#define IOPRIO_NR_LEVELS 8
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#define IOPRIO_BE_NR IOPRIO_NR_LEVELS
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enum {
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IOPRIO_WHO_PROCESS = 1,
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IOPRIO_WHO_PGRP,
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IOPRIO_WHO_USER,
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};
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/*
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* Fallback BE priority level.
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*/
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#define IOPRIO_NORM 4
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#define IOPRIO_BE_NORM IOPRIO_NORM
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#endif /* _UAPI_LINUX_IOPRIO_H */
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