Implemented linux ionice funtionality

.reniced.yaml.example

@@ -161,4 +161,12 @@ prio:
     - siriknowledged
     - triald
 
+ioprio:
+    - name:
+      - htop
+      - top
+      - atop
+      class: 2
+      prio: 1
+
 # vim: set ft=yaml et ai ts=2 sw=2 sts=2:

Makefile

@@ -1,15 +1,13 @@
 #!/usr/bin/env gmake -f
 
 BUILDOPTS=-ldflags="-s -w" -a -gcflags=all=-l -trimpath
-FILELIST=main.go types.go util.go
 
 BINARY=reniced
 
 all: clean build
 
 build:
-	go build ${BUILDOPTS} -o ${BINARY} ${FILELIST}
+	go build ${BUILDOPTS} -o ${BINARY}
-
 clean:
 	go clean
 

README.md

@@ -60,6 +60,27 @@ Unlike supplpied systemd unit, supplied System V Init script assumes reniced run
 setting must be set to true). Script also expects to find pid-file at **/var/run/reniced.pid** and executable itself at
 **/usr/sbin/reniced**.
 
+## Note on ionice operation
+
+Currently implemented only linux io prio. On all other reniced-supported systems it is noop. Please note that io
+priority can be set only by digits. Refer to *man ionice* for specific io classes and priorities inplemented there.
+
+Here is table with numbers for defined class and priorities.
+
+| class name | class number | list of possible priorities |
+|:-----------|-------------:|----------------------------:|
+| NONE       |0             |0                            |
+| RealTime   |1             |0, 1, 2, 3, 4, 5, 6, 7       |
+| BestEffort |2             |0, 1, 2, 3, 4, 5, 6, 7       |
+| Idle       |3             |0                            |
+
+None is default io prio if process is not ioreniced. And it is the same value and behaviour as BestEffort with priority
+of 4.
+
+The lower priority value means higher priority and process will eat more io.
+
+RealTime prio is not available for regular users but for root only.
+
 ## Special "thanks"
 
 To security assholes that disrupt workflows and make this world worse.

globals.go

@@ -0,0 +1,54 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"syscall"
+
+	"github.com/alitto/pond"
+)
+
+// Пул воркеров.
+var pool *pond.WorkerPool
+
+// Канал, в который приходят уведомления для хэндлера сигналов от траппера сигналов.
+var sigChan = make(chan os.Signal, 1)
+
+var kill = make(map[string]syscall.Signal)
+var renice = make(map[string]int)
+var ioreniceClass = make(map[string]uint32)
+var ioreniceClassdata = make(map[string]uint32)
+
+var NotImplementedError = fmt.Errorf("SYSCALL Not Implemented on current platform") //nolint:revive,stylecheck
+
+const IOPRIO_CLASS_NONE = uint32(0) //nolint:revive,stylecheck
+const IOPRIO_CLASS_RT = uint32(1)   //nolint:revive,stylecheck
+const IOPRIO_CLASS_BE = uint32(2)   //nolint:revive,stylecheck
+const IOPRIO_CLASS_IDLE = uint32(3) //nolint:revive,stylecheck
+
+const IOPRIO_WHO_PROCESS = 1 //nolint:revive,stylecheck
+const IOPRIO_WHO_PGRP = 2    //nolint:revive,stylecheck
+const IOPRIO_WHO_USER = 3    //nolint:revive,stylecheck
+
+const IOPRIO_CLASS_SHIFT = uint32(13)                            //nolint:revive,stylecheck
+const IOPRIO_PRIO_MASK = ((uint32(1) << IOPRIO_CLASS_SHIFT) - 1) //nolint:revive,stylecheck
+
+var ClassToString = map[uint32]string{
+	IOPRIO_CLASS_NONE: "none",
+	IOPRIO_CLASS_RT:   "realtime",
+	IOPRIO_CLASS_BE:   "best-effort",
+	IOPRIO_CLASS_IDLE: "idle",
+}
+
+var StringToClass = map[string]uint32{
+	"none":        IOPRIO_CLASS_NONE,
+	"0":           IOPRIO_CLASS_NONE,
+	"realtime":    IOPRIO_CLASS_RT,
+	"1":           IOPRIO_CLASS_RT,
+	"best-effort": IOPRIO_CLASS_BE,
+	"2":           IOPRIO_CLASS_BE,
+	"idle":        IOPRIO_CLASS_IDLE,
+	"3":           IOPRIO_CLASS_IDLE,
+}
+
+/* vim: set ft=go noet ai ts=4 sw=4 sts=4: */

ionice.go

@@ -0,0 +1,17 @@
+package main
+
+func PrioToClass(prio uint32) uint32 {
+	return prio >> IOPRIO_CLASS_SHIFT
+}
+
+func PrioToClassdata(prio uint32) uint32 {
+	return prio & IOPRIO_PRIO_MASK
+}
+
+func ClassAndClassdataToPrio(class uint32, classdata uint32) uint32 {
+	return ((class) << IOPRIO_CLASS_SHIFT) | classdata
+}
+
+func PrioToClassAndClassdata(prio uint32) (uint32, uint32) {
+	return PrioToClass(prio), PrioToClassdata(prio)
+}

ionice_linux.go

@@ -0,0 +1,80 @@
+//go:build linux
+// +build linux
+
+package main
+
+import (
+	"fmt"
+	"log"
+	"syscall"
+
+	proc "github.com/shirou/gopsutil/v3/process"
+)
+
+// GetIOPriority достаёт приоритет вводв-вывода для укаанного процесса.
+func GetIOPriority(which int, who int) (uint32, error) {
+	var (
+		err       error
+		r0, _, e1 = syscall.Syscall(syscall.SYS_IOPRIO_GET, uintptr(which), uintptr(who), 0)
+		prio      = uint32(r0)
+	)
+
+	if e1 != 0 {
+		err = fmt.Errorf(fmt.Sprintf("Received error number %v", e1))
+	}
+
+	return prio, err
+}
+
+// GetIOPriority ставит приоритет вводв-вывода для укаанного процесса.
+func SetIOPriority(which int, who int, prio uint32) error {
+	var (
+		err      error
+		_, _, e1 = syscall.Syscall(syscall.SYS_IOPRIO_SET, uintptr(which), uintptr(who), uintptr(prio))
+	)
+
+	if e1 != 0 {
+		err = fmt.Errorf(fmt.Sprintf("Received error number %v", e1))
+	}
+
+	return err
+}
+
+// IORenice выставляет процессу приоритет для операций ввода-вывода.
+func IORenice(cnf Config, p *proc.Process, processName string) {
+	if currentIOPrioLevel, err := GetIOPriority(IOPRIO_WHO_PROCESS, int(p.Pid)); err == nil {
+		currentClass, currentClassdata := PrioToClassAndClassdata(currentIOPrioLevel)
+		class := ioreniceClass[processName]
+		classdata := ioreniceClassdata[processName]
+
+		if class == currentClass && classdata == currentClassdata {
+			if cnf.Debug && currentIOPrioLevel != 0 { // 0 - это дефолтный уровень io niceness.
+				log.Printf(
+					"IONiceness for %s(%d) already set to %d %d",
+					processName,
+					p.Pid,
+					currentClass,
+					currentClassdata,
+				)
+			}
+		} else {
+			iopriority := ClassAndClassdataToPrio(class, classdata)
+
+			_ = SetIOPriority(IOPRIO_WHO_PROCESS, int(p.Pid), iopriority)
+
+			if cnf.Debug {
+				log.Printf(
+					"Set ioniceness for %s(%d) to %d %d (was %d %d)",
+					processName,
+					p.Pid,
+					class,
+					classdata,
+					currentClass,
+					currentClassdata,
+				)
+			}
+		}
+	} else {
+		log.Printf("Unable to get ioprio for %s(%d)", processName, p.Pid)
+	}
+}

ionice_other.go

@@ -0,0 +1,16 @@
+//go:build !linux
+// +build !linux
+
+package main
+
+import proc "github.com/shirou/gopsutil/v3/process"
+
+func GetIOPriority(which int, who int) (prio uint32, err error) {
+	return 0, NotImplementedError
+}
+
+func SetIOPriority(which int, who int, prio uint32) (err error) {
+	return NotImplementedError
+}
+
+func IORenice(cnf Config, p *proc.Process, processName string) {}

main.go

@@ -15,15 +15,6 @@ import (
 	proc "github.com/shirou/gopsutil/v3/process"
 )
 
-// Пул воркеров.
-var pool *pond.WorkerPool
-
-// Канал, в который приходят уведомления для хэндлера сигналов от траппера сигналов.
-var sigChan = make(chan os.Signal, 1)
-
-var kill = make(map[string]syscall.Signal)
-var renice = make(map[string]int)
-
 // main основная функция программы.
 func main() {
 	// Самое время поставить траппер сигналов.
@@ -86,7 +77,6 @@ func reniced(cnf Config) {
 		for _, p := range processList {
 			ok := pool.TrySubmit(func() {
 				if processName, err := p.Name(); err == nil {
-
 					// Для каждого процесса извлекаем его текущий priority.
 					if currentPrioLevel, err := syscall.Getpriority(syscall.PRIO_PROCESS, int(p.Pid)); err == nil {
 						if niceLevel := renice[processName]; niceLevel != 0 {
@@ -121,11 +111,18 @@ func reniced(cnf Config) {
 									)
 								}
 							} else if cnf.Debug {
-								log.Printf("Niceness for %d already set to %d", p.Pid, niceLevel)
+								log.Printf(
+									"Niceness for %s(%d) already set to %d",
+									processName,
+									p.Pid,
+									niceLevel,
+								)
 							}
 						}
 					}
 
+					IORenice(cnf, p, processName)
+
 					// Посылаем процессу сигналы, если таковые есть в конфиге.
 					if killSignal := kill[processName]; killSignal != 0 {
 						switch killSignal { //nolint:exhaustive
@@ -134,8 +131,9 @@ func reniced(cnf Config) {
 
 							if cnf.Debug {
 								log.Printf(
-									"Matching processName with killProcessname (%s), SIG%s sent",
+									"Matching processName with killProcessname %s(%d), SIG%s sent",
 									processName,
+									p.Pid,
 									strings.ToUpper(killSignal.String()),
 								)
 							}
@@ -145,8 +143,9 @@ func reniced(cnf Config) {
 
 							if cnf.Debug {
 								log.Printf(
-									"Matching processName with killProcessname (%s), SIG%s sent",
+									"Matching processName with killProcessname %s(%d), SIG%s sent",
 									processName,
+									p.Pid,
 									strings.ToUpper(killSignal.String()),
 								)
 							}

types.go

@@ -29,6 +29,8 @@ type Config struct {
 	Kill Kill `yaml:"kill,omitempty"`
 
 	Prio Prio `yaml:"prio,omitempty"`
+
+	IOPrio IOPrio `yaml:"ioprio,omitempty"`
 }
 
 type Prio []struct {
@@ -41,4 +43,10 @@ type Kill []struct {
 	Name []string `yaml:"name,omitempty"`
 }
 
+type IOPrio []struct {
+	Class uint32   `yaml:"class,omitempty"`
+	Prio  uint32   `yaml:"prio,omitempty"`
+	Name  []string `yaml:"name,omitempty"`
+}
+
 /* vim: set ft=go noet ai ts=4 sw=4 sts=4: */

util.go

@@ -122,6 +122,33 @@ func readConfFile(path string) (Config, error) {
 		}
 	}
 
+	for _, v := range cfg.IOPrio {
+		switch {
+		case len(v.Name) == 0:
+			log.Println("Skipping empty name entry in ioprio config block")
+		case v.Class > 3:
+			log.Printf("Skipping entry %s with class > 3 in ioprio config block", v.Name)
+		case v.Class == 0 && v.Prio != 0:
+			log.Printf("Skipping entry %s with class 0 and prio not 0 in ioprio config block", v.Name)
+		case v.Class == 3 && v.Prio != 0:
+			log.Printf("Skipping entry %s with class 3 and prio not 0 in ioprio config block", v.Name)
+		case v.Class == 1 && v.Prio > 7:
+			log.Printf("Skipping entry %s with class 1 and prio > 7 in ioprio config block", v.Name)
+		case v.Class == 2 && v.Prio > 7:
+			log.Printf("Skipping entry %s with class 2 and prio > 7 in ioprio config block", v.Name)
+		default:
+			for _, processName := range v.Name {
+				ioreniceClass[processName] = v.Class
+				ioreniceClassdata[processName] = v.Prio
+
+				if cfg.Debug {
+					log.Printf("Add %s to list of ionice class %d processes.", processName, v.Class)
+					log.Printf("Add %s to list of ionice prio %d processes.", processName, v.Prio)
+				}
+			}
+		}
+	}
+
 	for _, v := range cfg.Kill {
 		if len(v.Name) != 0 {
 			switch v.Sig {