test

Signed-off-by: Anastasios Papagiannis <[email protected]>
cilium · Mar 13, 2024 · f6f6beb · f6f6beb
1 parent 67bdc67
commit f6f6beb
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Showing 9 changed files with 390 additions and 52 deletions.
diff --git a/bpf/include/api.h b/bpf/include/api.h
@@ -227,7 +227,7 @@ static __u64 BPF_FUNC(get_attach_cookie, void *ctx);
 
 static long BPF_FUNC(loop, __u32 nr_loops, void *callback_fn, void *callback_ctx, __u64 flags);
 
-static long BPF_FUNC(ringbuf_output, void *data, uint64_t size, uint64_t flags);
+static long BPF_FUNC(ringbuf_output, void *ringbuf, void *data, uint64_t size, uint64_t flags);
 static void BPF_FUNC(ringbuf_reserve, void *ringbuf, uint64_t size, uint64_t flags);
 static void BPF_FUNC(ringbuf_submit, void *data, uint64_t flags);
 static void BPF_FUNC(ringbuf_discard, void *data, uint64_t flags);

diff --git a/bpf/lib/bpf_event.h b/bpf/lib/bpf_event.h
@@ -11,9 +11,8 @@ struct event {
 };
 
 struct {
-	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
-	__type(key, int);
-	__type(value, struct event);
+	__uint(type, BPF_MAP_TYPE_RINGBUF);
+	__uint(max_entries, 8LU * 1024LU * 1024LU); // 8MB
 } tcpmon_map SEC(".maps");
 
 #endif // __BPF_EVENT_H
diff --git a/bpf/lib/process.h b/bpf/lib/process.h
@@ -582,7 +582,7 @@ static inline __attribute__((always_inline)) void perf_event_output_metric(void
 	__u32 zero = 0;
 	long err;
 
-	err = perf_event_output(ctx, map, flags, data, size);
+	err = ringbuf_output(map, data, size, 0);
 	if (err < 0) {
 		valp = map_lookup_elem(&tg_stats_map, &zero);
 		if (valp)

diff --git a/pkg/bpf/perf_linux.go b/pkg/bpf/perf_linux.go
@@ -8,24 +8,15 @@ import (
 	"io"
 	"os"
 	"path/filepath"
-	"runtime"
 	"strings"
-
-	"golang.org/x/sys/unix"
 )
 
 const (
 	PossibleCPUSysfsPath = "/sys/devices/system/cpu/possible"
 )
 
 type PerfEventConfig struct {
-	NumCpus      int
-	NumPages     int
-	MapName      string
-	Type         int
-	Config       int
-	SampleType   int
-	WakeupEvents int
+	MapName string
 }
 
 // GetNumPossibleCPUs returns a total number of possible CPUS, i.e. CPUs that
@@ -74,30 +65,7 @@ func getNumPossibleCPUsFromReader(r io.Reader) int {
 // DefaultPerfEventConfig returns the default perf event configuration. It
 // relies on the map root to be set.
 func DefaultPerfEventConfig() *PerfEventConfig {
-	numCpus := GetNumPossibleCPUs()
-	if numCpus == 0 {
-		numCpus = runtime.NumCPU()
-	}
 	return &PerfEventConfig{
-		MapName:      filepath.Join(MapPrefixPath(), eventsMapName),
-		Type:         PERF_TYPE_SOFTWARE,
-		Config:       PERF_COUNT_SW_BPF_OUTPUT,
-		SampleType:   PERF_SAMPLE_RAW,
-		WakeupEvents: 1,
-		NumCpus:      numCpus,
-		NumPages:     128,
-	}
-}
-
-func UpdateElementFromPointers(fd int, structPtr, sizeOfStruct uintptr) error {
-	ret, _, err := unix.Syscall(
-		unix.SYS_BPF,
-		BPF_MAP_UPDATE_ELEM,
-		structPtr,
-		sizeOfStruct,
-	)
-	if ret != 0 || err != 0 {
-		return fmt.Errorf("Unable to update element for map with file descriptor %d: %s", fd, err)
+		MapName: filepath.Join(MapPrefixPath(), eventsMapName),
 	}
-	return nil
 }
diff --git a/pkg/observer/observer.go b/pkg/observer/observer.go
@@ -16,7 +16,7 @@ import (
 	"time"
 
 	"github.com/cilium/ebpf"
-	"github.com/cilium/ebpf/perf"
+	"github.com/cilium/ebpf/ringbuf"
 	"github.com/cilium/tetragon/pkg/api/ops"
 	"github.com/cilium/tetragon/pkg/api/readyapi"
 	"github.com/cilium/tetragon/pkg/bpf"
@@ -211,11 +211,9 @@ func (k *Observer) RunEvents(stopCtx context.Context, ready func()) error {
 	}
 	defer perfMap.Close()
 
-	rbSize := k.getRBSize(int(perfMap.MaxEntries()))
-	perfReader, err := perf.NewReader(perfMap, rbSize)
-
+	rd, err := ringbuf.NewReader(perfMap)
 	if err != nil {
-		return fmt.Errorf("creating perf array reader failed: %w", err)
+		return fmt.Errorf("opening ringbuf reader: %w", err)
 	}
 
 	// Inform caller that we're about to start processing events.
@@ -224,7 +222,7 @@ func (k *Observer) RunEvents(stopCtx context.Context, ready func()) error {
 
 	// We spawn go routine to read and process perf events,
 	// connected with main app through eventsQueue channel.
-	eventsQueue := make(chan *perf.Record, k.getRBQueueSize())
+	eventsQueue := make(chan *ringbuf.Record, k.getRBQueueSize())
 
 	// Listeners are ready and about to start reading from perf reader, tell
 	// user everything is ready.
@@ -237,7 +235,7 @@ func (k *Observer) RunEvents(stopCtx context.Context, ready func()) error {
 	go func() {
 		defer wg.Done()
 		for stopCtx.Err() == nil {
-			record, err := perfReader.Read()
+			record, err := rd.Read()
 			if err != nil {
 				// NOTE(JM and Djalal): count and log errors while excluding the stopping context
 				if stopCtx.Err() == nil {
@@ -256,11 +254,6 @@ func (k *Observer) RunEvents(stopCtx context.Context, ready func()) error {
 					k.recvCntr++
 					ringbufmetrics.PerfEventReceived.Inc()
 				}
-
-				if record.LostSamples > 0 {
-					atomic.AddUint64(&k.lostCntr, uint64(record.LostSamples))
-					ringbufmetrics.PerfEventLost.Add(float64(record.LostSamples))
-				}
 			}
 		}
 	}()
@@ -290,7 +283,7 @@ func (k *Observer) RunEvents(stopCtx context.Context, ready func()) error {
 
 	// Wait for context to be cancelled and then stop.
 	<-stopCtx.Done()
-	return perfReader.Close()
+	return rd.Close()
 }
 
 // Observer represents the link between the BPF perf ring and the listeners. It

diff --git a/vendor/github.com/cilium/ebpf/ringbuf/doc.go b/vendor/github.com/cilium/ebpf/ringbuf/doc.go