chore(ur): add RSS to reported stats (#10002)

For easier comparison in the future.

lib/ur/contract/contract.go

@@ -34,6 +34,7 @@ type Report struct {
 	SHA256Perf     float64 `json:"sha256Perf,omitempty" metric:"sha256_perf_mibps,summary" since:"1"`
 	HashPerf       float64 `json:"hashPerf,omitempty" metric:"hash_perf_mibps,summary" since:"1"`
 	MemorySize     int     `json:"memorySize,omitempty" metric:"memory_size_mib,summary" since:"1"`
+	ProcessRSSMiB  int     `json:"processRSSMiB,omitempty" metric:"process_rss_mib,summary" since:"1"`
 
 	// v2 fields
 

lib/ur/usage_report.go

@@ -14,12 +14,14 @@ import (
 	"math/rand"
 	"net"
 	"net/http"
+	"os"
 	"runtime"
 	"sort"
 	"strings"
 	"sync"
 	"time"
 
+	"github.com/shirou/gopsutil/v4/process"
 	"github.com/syncthing/syncthing/lib/build"
 	"github.com/syncthing/syncthing/lib/config"
 	"github.com/syncthing/syncthing/lib/connections"
@@ -119,6 +121,12 @@ func (s *Service) reportData(ctx context.Context, urVersion int, preview bool) (
 	report.MemorySize = int(memorySize() / 1024 / 1024)
 	report.NumCPU = runtime.NumCPU()
 
+	if proc, err := process.NewProcess(int32(os.Getpid())); err == nil {
+		if mem, err := proc.MemoryInfo(); err == nil {
+			report.ProcessRSSMiB = int(mem.RSS / 1024 / 1024)
+		}
+	}
+
 	for _, cfg := range s.cfg.Folders() {
 		report.RescanIntvs = append(report.RescanIntvs, cfg.RescanIntervalS)