~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/include/linux/ioprio.h

Version: ~ [ linux-5.2-rc1 ] ~ [ linux-5.1.2 ] ~ [ linux-5.0.16 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.43 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.119 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.176 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.179 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.139 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.67 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.39.4 ] ~ [ linux-2.6.38.8 ] ~ [ linux-2.6.37.6 ] ~ [ linux-2.6.36.4 ] ~ [ linux-2.6.35.14 ] ~ [ linux-2.6.34.15 ] ~ [ linux-2.6.33.20 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /* SPDX-License-Identifier: GPL-2.0 */
  2 #ifndef IOPRIO_H
  3 #define IOPRIO_H
  4 
  5 #include <linux/sched.h>
  6 #include <linux/sched/rt.h>
  7 #include <linux/iocontext.h>
  8 
  9 /*
 10  * Gives us 8 prio classes with 13-bits of data for each class
 11  */
 12 #define IOPRIO_CLASS_SHIFT      (13)
 13 #define IOPRIO_PRIO_MASK        ((1UL << IOPRIO_CLASS_SHIFT) - 1)
 14 
 15 #define IOPRIO_PRIO_CLASS(mask) ((mask) >> IOPRIO_CLASS_SHIFT)
 16 #define IOPRIO_PRIO_DATA(mask)  ((mask) & IOPRIO_PRIO_MASK)
 17 #define IOPRIO_PRIO_VALUE(class, data)  (((class) << IOPRIO_CLASS_SHIFT) | data)
 18 
 19 #define ioprio_valid(mask)      (IOPRIO_PRIO_CLASS((mask)) != IOPRIO_CLASS_NONE)
 20 
 21 /*
 22  * These are the io priority groups as implemented by CFQ. RT is the realtime
 23  * class, it always gets premium service. BE is the best-effort scheduling
 24  * class, the default for any process. IDLE is the idle scheduling class, it
 25  * is only served when no one else is using the disk.
 26  */
 27 enum {
 28         IOPRIO_CLASS_NONE,
 29         IOPRIO_CLASS_RT,
 30         IOPRIO_CLASS_BE,
 31         IOPRIO_CLASS_IDLE,
 32 };
 33 
 34 /*
 35  * 8 best effort priority levels are supported
 36  */
 37 #define IOPRIO_BE_NR    (8)
 38 
 39 enum {
 40         IOPRIO_WHO_PROCESS = 1,
 41         IOPRIO_WHO_PGRP,
 42         IOPRIO_WHO_USER,
 43 };
 44 
 45 /*
 46  * Fallback BE priority
 47  */
 48 #define IOPRIO_NORM     (4)
 49 
 50 /*
 51  * if process has set io priority explicitly, use that. if not, convert
 52  * the cpu scheduler nice value to an io priority
 53  */
 54 static inline int task_nice_ioprio(struct task_struct *task)
 55 {
 56         return (task_nice(task) + 20) / 5;
 57 }
 58 
 59 /*
 60  * This is for the case where the task hasn't asked for a specific IO class.
 61  * Check for idle and rt task process, and return appropriate IO class.
 62  */
 63 static inline int task_nice_ioclass(struct task_struct *task)
 64 {
 65         if (task->policy == SCHED_IDLE)
 66                 return IOPRIO_CLASS_IDLE;
 67         else if (task_is_realtime(task))
 68                 return IOPRIO_CLASS_RT;
 69         else
 70                 return IOPRIO_CLASS_BE;
 71 }
 72 
 73 /*
 74  * For inheritance, return the highest of the two given priorities
 75  */
 76 extern int ioprio_best(unsigned short aprio, unsigned short bprio);
 77 
 78 extern int set_task_ioprio(struct task_struct *task, int ioprio);
 79 
 80 #endif
 81 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp