From 67cae770344f23658562dffff95e77967543c475 Mon Sep 17 00:00:00 2001 From: "Anthony G. Basile" Date: Sat, 17 Nov 2012 10:13:59 -0500 Subject: Rename src/shared to src/include, a saner name --- src/include/ioprio.h | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 src/include/ioprio.h (limited to 'src/include/ioprio.h') diff --git a/src/include/ioprio.h b/src/include/ioprio.h new file mode 100644 index 0000000000..9800fc2553 --- /dev/null +++ b/src/include/ioprio.h @@ -0,0 +1,57 @@ +#ifndef IOPRIO_H +#define IOPRIO_H + +/* This is minimal version of Linux' linux/ioprio.h header file, which + * is licensed GPL2 */ + +#include +#include + +/* + * Gives us 8 prio classes with 13-bits of data for each class + */ +#define IOPRIO_BITS (16) +#define IOPRIO_CLASS_SHIFT (13) +#define IOPRIO_PRIO_MASK ((1UL << IOPRIO_CLASS_SHIFT) - 1) + +#define IOPRIO_PRIO_CLASS(mask) ((mask) >> IOPRIO_CLASS_SHIFT) +#define IOPRIO_PRIO_DATA(mask) ((mask) & IOPRIO_PRIO_MASK) +#define IOPRIO_PRIO_VALUE(class, data) (((class) << IOPRIO_CLASS_SHIFT) | data) + +#define ioprio_valid(mask) (IOPRIO_PRIO_CLASS((mask)) != IOPRIO_CLASS_NONE) + +/* + * These are the io priority groups as implemented by CFQ. RT is the realtime + * class, it always gets premium service. 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, +}; + +/* + * 8 best effort priority levels are supported + */ +#define IOPRIO_BE_NR (8) + +enum { + IOPRIO_WHO_PROCESS = 1, + IOPRIO_WHO_PGRP, + IOPRIO_WHO_USER, +}; + +static inline int ioprio_set(int which, int who, int ioprio) +{ + return syscall(__NR_ioprio_set, which, who, ioprio); +} + +static inline int ioprio_get(int which, int who) +{ + return syscall(__NR_ioprio_get, which, who); +} + +#endif -- cgit v1.2.3-54-g00ecf