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package internal
import "C"
import (
"context"
"fmt"
"os"
"os/signal"
"runtime/pprof"
"syscall"
"time"
"ior/internal/flags"
"ior/internal/tracepoints"
bpf "github.com/aquasecurity/libbpfgo"
)
func attachTracepoints(flags flags.Flags, bpfModule *bpf.Module) error {
for _, name := range tracepoints.List {
if !flags.AttachTracepoint(name) {
continue
}
fmt.Println("Attaching tracepoint", name)
prog, err := bpfModule.GetProgram(fmt.Sprintf("handle_%s", name))
if err != nil {
return fmt.Errorf("Failed to get BPF program handle_%s: %v", name, err)
}
fmt.Println("Attached prog handle_", name)
if _, err = prog.AttachTracepoint("syscalls", name); err != nil {
// OK, older Kernel versions may not have this tracepoint!
fmt.Printf("Failed to attach to %s tracepoint: %v, kernel version may be too old, skipping", name, err)
continue
}
fmt.Println("Attached tracepoint ", name)
}
return nil
}
func Run(flags flags.Flags) {
bpfModule, err := bpf.NewModuleFromFile("ior.bpf.o")
if err != nil {
panic(err)
}
defer bpfModule.Close()
if err := flags.ResizeBPFMaps(bpfModule); err != nil {
panic(err)
}
if err := flags.SetBPF(bpfModule); err != nil {
panic(err)
}
if err := bpfModule.BPFLoadObject(); err != nil {
panic(err)
}
if err := attachTracepoints(flags, bpfModule); err != nil {
panic(err)
}
// 4096 channel size, minimises event drops
ch := make(chan []byte, 4096)
rb, err := bpfModule.InitRingBuf("event_map", ch)
if err != nil {
panic(err)
}
rb.Poll(300)
pprofDone := make(chan struct{})
var cpuProfile, memProfile *os.File
if flags.PprofEnable {
if cpuProfile, err = os.Create("ior.cpuprofile"); err != nil {
panic(err)
}
if memProfile, err = os.Create("ior.memprofile"); err != nil {
panic(err)
}
pprof.StartCPUProfile(cpuProfile)
} else {
close(pprofDone)
}
loop := newEventLoop(flags)
duration := time.Duration(flags.Duration) * time.Second
fmt.Println("Probing for", duration)
ctx, cancel := context.WithTimeout(context.Background(), duration)
c := make(chan os.Signal, 1)
signal.Notify(c, os.Interrupt, syscall.SIGTERM)
go func() {
<-c
cancel()
}()
go func() {
<-ctx.Done()
fmt.Println(loop.stats())
if flags.PprofEnable {
fmt.Println("Stoppig profiling, writing ior.cpuprofile and ior.memprofile")
pprof.StopCPUProfile()
pprof.WriteHeapProfile(memProfile)
close(pprofDone)
}
}()
startTime := time.Now()
loop.run(ctx, ch)
totalDuration := time.Since(startTime)
<-pprofDone
fmt.Println("Good bye... (unloading BPF tracepoints will take a few seconds...) after", totalDuration)
}
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