From b209858100d6576eb364f3508bce3cc9622259e5 Mon Sep 17 00:00:00 2001
From: nolouch <nolouch@gmail.com>
Date: Wed, 24 Jul 2024 16:53:06 +0800
Subject: [PATCH] address comments

Signed-off-by: nolouch <nolouch@gmail.com>
---
 client/resource_group/controller/limiter.go | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/client/resource_group/controller/limiter.go b/client/resource_group/controller/limiter.go
index 3349c096415..faa2bad927e 100644
--- a/client/resource_group/controller/limiter.go
+++ b/client/resource_group/controller/limiter.go
@@ -335,7 +335,7 @@ func (lim *Limiter) Reconfigure(now time.Time,
 ) {
 	lim.mu.Lock()
 	defer lim.mu.Unlock()
-	logControllerTrace("[resource group controller] before reconfigure", zap.Float64("old-tokens", lim.tokens), zap.Float64("old-rate", float64(lim.limit)), zap.Float64("old-notify-threshold", args.NotifyThreshold), zap.Int64("old-burst", lim.burst))
+	logControllerTrace("[resource group controller] before reconfigure", zap.String("name", lim.name), zap.Float64("old-tokens", lim.tokens), zap.Float64("old-rate", float64(lim.limit)), zap.Float64("old-notify-threshold", args.NotifyThreshold), zap.Int64("old-burst", lim.burst))
 	if args.NewBurst < 0 {
 		lim.last = now
 		lim.tokens = args.NewTokens
@@ -351,7 +351,7 @@ func (lim *Limiter) Reconfigure(now time.Time,
 		opt(lim)
 	}
 	lim.maybeNotify()
-	logControllerTrace("[resource group controller] after reconfigure", zap.Float64("tokens", lim.tokens), zap.Float64("rate", float64(lim.limit)), zap.Float64("notify-threshold", args.NotifyThreshold), zap.Int64("burst", lim.burst))
+	logControllerTrace("[resource group controller] after reconfigure", zap.String("name", lim.name), zap.Float64("tokens", lim.tokens), zap.Float64("rate", float64(lim.limit)), zap.Float64("notify-threshold", args.NotifyThreshold), zap.Int64("burst", lim.burst))
 }
 
 // AvailableTokens decreases the amount of tokens currently available.
@@ -362,6 +362,14 @@ func (lim *Limiter) AvailableTokens(now time.Time) float64 {
 	return tokens
 }
 
+func (lim *Limiter) updateLast(t time.Time) {
+	// make sure lim.last is monotonic
+	// see issue: https://github.com/tikv/pd/issues/8435.
+	if lim.last.Before(t) {
+		lim.last = t
+	}
+}
+
 const reserveWarnLogInterval = 10 * time.Millisecond
 
 // reserveN is a helper method for Reserve.
@@ -406,9 +414,7 @@ func (lim *Limiter) reserveN(now time.Time, n float64, maxFutureReserve time.Dur
 	}
 	// Update state
 	if ok {
-		if lim.last.Before(now) {
-			lim.last = now
-		}
+		lim.updateLast(now)
 		lim.tokens = tokens
 		lim.maybeNotify()
 	} else {
@@ -426,9 +432,7 @@ func (lim *Limiter) reserveN(now time.Time, n float64, maxFutureReserve time.Dur
 				zap.Int("remaining-notify-times", lim.remainingNotifyTimes),
 				zap.String("name", lim.name))
 		}
-		if lim.last.Before(now) {
-			lim.last = last
-		}
+		lim.updateLast(last)
 		if lim.limit == 0 {
 			lim.notify()
 		} else if lim.remainingNotifyTimes > 0 {