In the tags command, print percentages relative to profile total.

Before this change percentages were relative to the tag total and this
sometimes causes confusion for users as it makes it look like the tag is
set for all samples when it's not.

Note that the percentage calculation as implemented does not attempt to
be friendly to samples where a given tag has multiple values. Multiple
values per tag per sample are discouraged and we should deprecate them.
Maybe we should make pprof print a warning for such profiles.

Author: aalexand

internal/driver/testdata/pprof.cpu.tags

@@ -1,13 +1,13 @@
- key1: Total 1.1s
+ key1: Total 1.1s of 1.1s (  100%)
           1.0s (89.29%): tag1
        100.0ms ( 8.93%): tag2
         10.0ms ( 0.89%): tag3
         10.0ms ( 0.89%): tag4
 
- key2: Total 1.0s
-         1.0s (99.02%): tag1
-       10.0ms ( 0.98%): tag2
+ key2: Total 1.0s of 1.1s (91.07%)
+         1.0s (90.18%): tag1
+       10.0ms ( 0.89%): tag2
 
- key3: Total 100.0ms
-       100.0ms (  100%): tag2
+ key3: Total 100.0ms of 1.1s ( 8.93%)
+       100.0ms ( 8.93%): tag2
 

internal/driver/testdata/pprof.cpu.tags.focus.ignore

@@ -1,6 +1,6 @@
- key1: Total 100.0ms
+ key1: Total 100.0ms of 100.0ms (  100%)
        100.0ms (  100%): tag2
 
- key3: Total 100.0ms
+ key3: Total 100.0ms of 100.0ms (  100%)
        100.0ms (  100%): tag2
 

internal/driver/testdata/pprof.heap.tags

@@ -1,4 +1,4 @@
- bytes: Total 98.6MB
+ bytes: Total 98.6MB of 98.6MB (  100%)
           62.5MB (63.37%): 1.56MB
           31.2MB (31.68%): 400kB
            3.9MB ( 3.96%): 200kB

internal/driver/testdata/pprof.heap.tags.unit

@@ -1,4 +1,4 @@
- bytes: Total 103424000.0B
+ bytes: Total 103424000.0B of 103424000.0B (  100%)
         65536000.0B (63.37%): 1638400B
         32768000.0B (31.68%): 409600B
          4096000.0B ( 3.96%): 204800B

internal/driver/testdata/pprof.heap_request.tags.focus

@@ -1,8 +1,8 @@
- bytes: Total 93.8MB
+ bytes: Total 93.8MB of 93.8MB (  100%)
         62.5MB (66.67%): 1.56MB
         31.2MB (33.33%): 400kB
 
- request: Total 93.8MB
+ request: Total 93.8MB of 93.8MB (  100%)
           62.5MB (66.67%): 1.56MB
           31.2MB (33.33%): 400kB
 

internal/report/report.go

@@ -699,21 +699,28 @@ func printTags(w io.Writer, rpt *Report) error {
 	p := rpt.prof
 
 	o := rpt.options
-	formatTag := func(v int64, key string) string {
-		return measurement.ScaledLabel(v, key, o.OutputUnit)
+	formatTag := func(v int64, unit string) string {
+		return measurement.ScaledLabel(v, unit, o.OutputUnit)
 	}
 
-	// Hashtable to keep accumulate tags as key,value,count.
+	// Accumulate tags as key,value,count.
 	tagMap := make(map[string]map[string]int64)
+	// In the total and residue calculation we assume single value per tag per
+	// sample. Multiple values are encodable in the format but are discouraged.
+	tagTotal := make(map[string]int64)
+	var profileTotal int64
 	for _, s := range p.Sample {
+		sampleValue := o.SampleValue(s.Value)
+		profileTotal += sampleValue
 		for key, vals := range s.Label {
 			for _, val := range vals {
 				valueMap, ok := tagMap[key]
 				if !ok {
 					valueMap = make(map[string]int64)
 					tagMap[key] = valueMap
 				}
-				valueMap[val] += o.SampleValue(s.Value)
+				valueMap[val] += sampleValue
+				tagTotal[key] += sampleValue
 			}
 		}
 		for key, vals := range s.NumLabel {
@@ -725,7 +732,8 @@ func printTags(w io.Writer, rpt *Report) error {
 					valueMap = make(map[string]int64)
 					tagMap[key] = valueMap
 				}
-				valueMap[val] += o.SampleValue(s.Value)
+				valueMap[val] += sampleValue
+				tagTotal[key] += sampleValue
 			}
 		}
 	}
@@ -735,21 +743,24 @@ func printTags(w io.Writer, rpt *Report) error {
 		tagKeys = append(tagKeys, &graph.Tag{Name: key})
 	}
 	tabw := tabwriter.NewWriter(w, 0, 0, 1, ' ', tabwriter.AlignRight)
+	fp, up := measurement.Scale(profileTotal, o.SampleUnit, o.OutputUnit)
 	for _, tagKey := range graph.SortTags(tagKeys, true) {
-		var total int64
 		key := tagKey.Name
 		tags := make([]*graph.Tag, 0, len(tagMap[key]))
 		for t, c := range tagMap[key] {
-			total += c
 			tags = append(tags, &graph.Tag{Name: t, Flat: c})
 		}
 
-		f, u := measurement.Scale(total, o.SampleUnit, o.OutputUnit)
-		fmt.Fprintf(tabw, "%s:\t Total %.1f%s\n", key, f, u)
+		f, u := measurement.Scale(tagTotal[tagKey.Name], o.SampleUnit, o.OutputUnit)
+		if profileTotal > 0 {
+			fmt.Fprintf(tabw, "%s:\t Total %.1f%s of %.1f%s (%s)\n", key, f, u, fp, up, measurement.Percentage(tagTotal[tagKey.Name], profileTotal))
+		} else {
+			fmt.Fprintf(tabw, "%s:\t Total %.1f%s of %.1f%s\n", key, f, u, fp, up)
+		}
 		for _, t := range graph.SortTags(tags, true) {
 			f, u := measurement.Scale(t.FlatValue(), o.SampleUnit, o.OutputUnit)
-			if total > 0 {
-				fmt.Fprintf(tabw, " \t%.1f%s (%s):\t %s\n", f, u, measurement.Percentage(t.FlatValue(), total), t.Name)
+			if profileTotal > 0 {
+				fmt.Fprintf(tabw, " \t%.1f%s (%s):\t %s\n", f, u, measurement.Percentage(t.FlatValue(), profileTotal), t.Name)
 			} else {
 				fmt.Fprintf(tabw, " \t%.1f%s:\t %s\n", f, u, t.Name)
 			}