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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>
78 lines
1.7 KiB
C
78 lines
1.7 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_BE, IOPRIO_BE_NORM)
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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 (task_is_realtime(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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/*
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* If the calling process 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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static inline int get_current_ioprio(void)
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{
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struct io_context *ioc = current->io_context;
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if (ioc)
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return ioc->ioprio;
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return IOPRIO_DEFAULT;
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}
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/*
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* For inheritance, return the highest of the two given priorities
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*/
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extern int ioprio_best(unsigned short aprio, unsigned short bprio);
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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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