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git.ipfire.org Git - thirdparty/systemd.git/blob - src/basic/ioprio.h
4 /* This is minimal version of Linux' linux/ioprio.h header file, which
7 #include <sys/syscall.h>
11 * Gives us 8 prio classes with 13-bits of data for each class
13 #define IOPRIO_BITS 16
14 #define IOPRIO_N_CLASSES 8
15 #define IOPRIO_CLASS_SHIFT 13
16 #define IOPRIO_PRIO_DATA_MASK ((1UL << IOPRIO_CLASS_SHIFT) - 1)
18 #define IOPRIO_PRIO_CLASS(mask) ((mask) >> IOPRIO_CLASS_SHIFT)
19 #define IOPRIO_PRIO_DATA(mask) ((mask) & IOPRIO_PRIO_DATA_MASK)
20 #define IOPRIO_PRIO_VALUE(class, data) (((class) << IOPRIO_CLASS_SHIFT) | data)
22 #define ioprio_valid(mask) (IOPRIO_PRIO_CLASS((mask)) != IOPRIO_CLASS_NONE)
25 * These are the io priority groups as implemented by CFQ. RT is the realtime
26 * class, it always gets premium service. BE is the best-effort scheduling
27 * class, the default for any process. IDLE is the idle scheduling class, it
28 * is only served when no one else is using the disk.
38 * 8 best effort priority levels are supported
40 #define IOPRIO_BE_NR (8)
43 IOPRIO_WHO_PROCESS
= 1,
48 static inline int ioprio_set(int which
, int who
, int ioprio
) {
49 return syscall(__NR_ioprio_set
, which
, who
, ioprio
);
52 static inline int ioprio_get(int which
, int who
) {
53 return syscall(__NR_ioprio_get
, which
, who
);