Reduce size of ringbuffer

Author: christos68k

tracer/tracer.go

@@ -624,12 +624,14 @@ func loadAllMaps(coll *cebpf.CollectionSpec, cfg *Config,
 
 	adaption["sched_times"] = schedTimesSize(cfg.OffCPUThreshold)
 
-	// Allow for 10s of 'burst' trace data
-	// TODO: Change to present CPUs as runtime.NumCPU is fixed for the lifetime of the process?
-	ringbufSize := 10 * uint32(cfg.SamplesPerSecond*runtime.NumCPU()*support.Sizeof_Trace)
-
+	// Allow for 1s of 'burst' trace data
+	// TODO: Base this on present CPUs instead, as runtime.NumCPU is fixed
+	// for the lifetime of the process?
+	ringbufSize := uint32(cfg.SamplesPerSecond * runtime.NumCPU() * support.Sizeof_Trace)
 	adaption["trace_events"] = uint32(util.NextPowerOfTwo(uint(ringbufSize)))
 
+	log.Infof("Using %d bytes ringbuffer size")
+
 	for i := support.StackDeltaBucketSmallest; i <= support.StackDeltaBucketLargest; i++ {
 		mapName := fmt.Sprintf("exe_id_to_%d_stack_deltas", i)
 		adaption[mapName] = 1 << uint32(exeIDToStackDeltasSize+cfg.MapScaleFactor)