diff options
Diffstat (limited to 'include/uapi/linux/ioprio.h')
| -rw-r--r-- | include/uapi/linux/ioprio.h | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/include/uapi/linux/ioprio.h b/include/uapi/linux/ioprio.h index f70f2596a6bf..4444b4e4fdad 100644 --- a/include/uapi/linux/ioprio.h +++ b/include/uapi/linux/ioprio.h @@ -17,7 +17,7 @@ ((data) & IOPRIO_PRIO_MASK)) /* - * These are the io priority groups as implemented by the BFQ and mq-deadline + * These are the io priority classes 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 @@ -32,11 +32,20 @@ enum { }; /* - * The RT and BE priority classes both support up to 8 priority levels. + * The RT and BE priority classes both support up to 8 priority levels that + * can be specified using the lower 3-bits of the priority data. */ -#define IOPRIO_NR_LEVELS 8 -#define IOPRIO_BE_NR IOPRIO_NR_LEVELS +#define IOPRIO_LEVEL_NR_BITS 3 +#define IOPRIO_NR_LEVELS (1 << IOPRIO_LEVEL_NR_BITS) +#define IOPRIO_LEVEL_MASK (IOPRIO_NR_LEVELS - 1) +#define IOPRIO_PRIO_LEVEL(ioprio) ((ioprio) & IOPRIO_LEVEL_MASK) +#define IOPRIO_BE_NR IOPRIO_NR_LEVELS + +/* + * Possible values for the "which" argument of the ioprio_get() and + * ioprio_set() system calls (see "man ioprio_set"). + */ enum { IOPRIO_WHO_PROCESS = 1, IOPRIO_WHO_PGRP, @@ -44,7 +53,7 @@ enum { }; /* - * Fallback BE priority level. + * Fallback BE class priority level. */ #define IOPRIO_NORM 4 #define IOPRIO_BE_NORM IOPRIO_NORM |