From: Michael Anthony Knyszek <mknyszek@google.com>
Date: Wed, 18 May 2022 22:07:46 +0000 (+0000)
Subject: runtime: use correct heap goal in GC traces
X-Git-Tag: go1.19beta1~171
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=a6c75aa5c3009e6c4179ef9429b3efbd708499bf;p=gostls13.git

runtime: use correct heap goal in GC traces

Currently gctrace and gcpacertrace recompute the heap goal for
end-of-cycle information but this is incorrect.

Because both of these traces are printing stats from the previous cycle
in this case, they should print the heap goal at the end of the previous
cycle.

Change-Id: I967621cbaff9f331cd3e361de8850ddfe0cfc099
Reviewed-on: https://go-review.googlesource.com/c/go/+/407138
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: David Chase <drchase@google.com>
---

diff --git a/src/runtime/mgc.go b/src/runtime/mgc.go
index 8b323c5bf7..ac4f5d0335 100644
--- a/src/runtime/mgc.go
+++ b/src/runtime/mgc.go
@@ -1118,7 +1118,7 @@ func gcMarkTermination() {
 		}
 		print(" ms cpu, ",
 			work.heap0>>20, "->", work.heap1>>20, "->", work.heap2>>20, " MB, ",
-			gcController.heapGoal()>>20, " MB goal, ",
+			gcController.lastHeapGoal>>20, " MB goal, ",
 			atomic.Load64(&gcController.maxStackScan)>>20, " MB stacks, ",
 			gcController.globalsScan>>20, " MB globals, ",
 			work.maxprocs, " P")
diff --git a/src/runtime/mgcpacer.go b/src/runtime/mgcpacer.go
index 2487f58dc5..87ad4b0a15 100644
--- a/src/runtime/mgcpacer.go
+++ b/src/runtime/mgcpacer.go
@@ -731,12 +731,11 @@ func (c *gcControllerState) endCycle(now int64, procs int, userForced bool) {
 	}
 
 	if debug.gcpacertrace > 0 {
-		heapGoal := c.heapGoal()
 		printlock()
 		goal := gcGoalUtilization * 100
 		print("pacer: ", int(utilization*100), "% CPU (", int(goal), " exp.) for ")
 		print(c.heapScanWork.Load(), "+", c.stackScanWork.Load(), "+", c.globalsScanWork.Load(), " B work (", c.lastHeapScan+c.lastStackScan+c.globalsScan, " B exp.) ")
-		print("in ", c.triggered, " B -> ", c.heapLive, " B (∆goal ", int64(c.heapLive)-int64(heapGoal), ", cons/mark ", oldConsMark, ")")
+		print("in ", c.triggered, " B -> ", c.heapLive, " B (∆goal ", int64(c.heapLive)-int64(c.lastHeapGoal), ", cons/mark ", oldConsMark, ")")
 		if !ok {
 			print("[controller reset]")
 		}