gossip: use crtime.Mono

crtime.NowMono is a little more efficient. I haven't seen this on any
profiles but noted it when reviewing some code recently. We also remove
an extra clock reading that wasn't needed.

Epic: none
Release note: None

Author: stevendanna

pkg/gossip/BUILD.bazel

@@ -38,6 +38,7 @@ go_library(
         "//pkg/util/syncutil",
         "//pkg/util/timeutil",
         "//pkg/util/uuid",
+        "@com_github_cockroachdb_crlib//crtime",
         "@com_github_cockroachdb_errors//:errors",
         "@com_github_cockroachdb_logtags//:logtags",
         "@com_github_cockroachdb_redact//:redact",

pkg/gossip/gossip.go

@@ -66,6 +66,7 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/util/syncutil"
 	"github.com/cockroachdb/cockroach/pkg/util/timeutil"
 	"github.com/cockroachdb/cockroach/pkg/util/uuid"
+	"github.com/cockroachdb/crlib/crtime"
 	"github.com/cockroachdb/errors"
 	"github.com/cockroachdb/logtags"
 	"github.com/cockroachdb/redact"
@@ -1619,7 +1620,7 @@ func (g *Gossip) TestingAddInfoProtoAndWaitForAllCallbacks(
 				method: func(_ string, _ roachpb.Value) {
 					wg.Done()
 				},
-				schedulingTime: timeutil.Now(),
+				schedulingTime: crtime.NowMono(),
 			})
 			cb.cw.mu.Unlock()
 		}

pkg/gossip/infostore.go

@@ -22,6 +22,7 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/util/stop"
 	"github.com/cockroachdb/cockroach/pkg/util/syncutil"
 	"github.com/cockroachdb/cockroach/pkg/util/timeutil"
+	"github.com/cockroachdb/crlib/crtime"
 	"github.com/cockroachdb/errors"
 	"github.com/cockroachdb/redact"
 )
@@ -77,7 +78,7 @@ type callback struct {
 // a callback.
 type callbackWorkItem struct {
 	// schedulingTime is the time when the callback was scheduled.
-	schedulingTime time.Time
+	schedulingTime crtime.Mono
 	method         Callback
 	key            string
 	content        roachpb.Value
@@ -266,17 +267,17 @@ func (is *infoStore) launchCallbackWorker(ambient log.AmbientContext, cw *callba
 
 				// Execute all the callbacks in the queue, making sure to update the
 				// metrics accordingly.
+				afterQueue := crtime.NowMono()
 				for _, work := range wq {
-					afterQueue := timeutil.Now()
-					queueDur := afterQueue.Sub(work.schedulingTime)
+					queueDur := work.schedulingTime.Sub(afterQueue)
 					is.metrics.CallbacksPending.Dec(1)
 					if queueDur >= minCallbackDurationToRecord {
 						is.metrics.CallbacksPendingDuration.RecordValue(queueDur.Nanoseconds())
 					}
 
 					work.method(work.key, work.content)
 
-					afterProcess := timeutil.Now()
+					afterProcess := crtime.NowMono()
 					processDur := afterProcess.Sub(afterQueue)
 					is.metrics.CallbacksProcessed.Inc(1)
 					if processDur > minCallbackDurationToRecord {
@@ -469,7 +470,7 @@ func (is *infoStore) runCallbacks(key string, content roachpb.Value, callbacks .
 	}
 
 	// Add the callbacks to the callback work list.
-	beforeQueue := timeutil.Now()
+	beforeQueue := crtime.NowMono()
 	for _, cb := range callbacks {
 		cb.cw.mu.Lock()
 		is.metrics.CallbacksPending.Inc(1)