projects / mirror_ubuntu-bionic-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| 22e2c507 JA |
1 | #ifndef IOPRIO_H |
| 2 | #define IOPRIO_H | |
| 3 | ||
| 4 | #include <linux/sched.h> | |
| 5 | ||
| 6 | /* | |
| 7 | * Gives us 8 prio classes with 13-bits of data for each class | |
| 8 | */ | |
| 9 | #define IOPRIO_BITS (16) | |
| 10 | #define IOPRIO_CLASS_SHIFT (13) | |
| 11 | #define IOPRIO_PRIO_MASK ((1UL << IOPRIO_CLASS_SHIFT) - 1) | |
| 12 | ||
| 13 | #define IOPRIO_PRIO_CLASS(mask) ((mask) >> IOPRIO_CLASS_SHIFT) | |
| 14 | #define IOPRIO_PRIO_DATA(mask) ((mask) & IOPRIO_PRIO_MASK) | |
| 3b18152c | 15 | #define IOPRIO_PRIO_VALUE(class, data) (((class) << IOPRIO_CLASS_SHIFT) | data) |
| 22e2c507 JA |
16 | |
| 17 | #define ioprio_valid(mask) (IOPRIO_PRIO_CLASS((mask)) != IOPRIO_CLASS_NONE) | |
| 18 | ||
| 19 | /* | |
| 20 | * These are the io priority groups as implemented by CFQ. RT is the realtime | |
| 21 | * class, it always gets premium service. BE is the best-effort scheduling | |
| 22 | * class, the default for any process. IDLE is the idle scheduling class, it | |
| 23 | * is only served when no one else is using the disk. | |
| 24 | */ | |
| 25 | enum { | |
| 26 | IOPRIO_CLASS_NONE, | |
| 27 | IOPRIO_CLASS_RT, | |
| 28 | IOPRIO_CLASS_BE, | |
| 29 | IOPRIO_CLASS_IDLE, | |
| 30 | }; | |
| 31 | ||
| 32 | /* | |
| 33 | * 8 best effort priority levels are supported | |
| 34 | */ | |
| 35 | #define IOPRIO_BE_NR (8) | |
| 36 | ||
| 22e2c507 JA |
37 | enum { |
| 38 | IOPRIO_WHO_PROCESS = 1, | |
| 39 | IOPRIO_WHO_PGRP, | |
| 40 | IOPRIO_WHO_USER, | |
| 41 | }; | |
| 42 | ||
| 43 | /* | |
| 44 | * if process has set io priority explicitly, use that. if not, convert | |
| 45 | * the cpu scheduler nice value to an io priority | |
| 46 | */ | |
| 47 | #define IOPRIO_NORM (4) | |
| 48 | static inline int task_ioprio(struct task_struct *task) | |
| 49 | { | |
| 50 | WARN_ON(!ioprio_valid(task->ioprio)); | |
| 51 | return IOPRIO_PRIO_DATA(task->ioprio); | |
| 52 | } | |
| 53 | ||
| 54 | static inline int task_nice_ioprio(struct task_struct *task) | |
| 55 | { | |
| 56 | return (task_nice(task) + 20) / 5; | |
| 57 | } | |
| 58 | ||
| 59 | /* | |
| 60 | * For inheritance, return the highest of the two given priorities | |
| 61 | */ | |
| 62 | static inline int ioprio_best(unsigned short aprio, unsigned short bprio) | |
| 63 | { | |
| 64 | unsigned short aclass = IOPRIO_PRIO_CLASS(aprio); | |
| 65 | unsigned short bclass = IOPRIO_PRIO_CLASS(bprio); | |
| 66 | ||
| 67 | if (!ioprio_valid(aprio)) | |
| 68 | return bprio; | |
| 69 | if (!ioprio_valid(bprio)) | |
| 70 | return aprio; | |
| 71 | ||
| 72 | if (aclass == IOPRIO_CLASS_NONE) | |
| 73 | aclass = IOPRIO_CLASS_BE; | |
| 74 | if (bclass == IOPRIO_CLASS_NONE) | |
| 75 | bclass = IOPRIO_CLASS_BE; | |
| 76 | ||
| 77 | if (aclass == bclass) | |
| 78 | return min(aprio, bprio); | |
| 79 | if (aclass > bclass) | |
| 80 | return bprio; | |
| 81 | else | |
| 82 | return aprio; | |
| 83 | } | |
| 84 | ||
| 85 | #endif |