From: Michael Anthony Knyszek <mknyszek@google.com>
Date: Thu, 2 Jun 2022 21:10:26 +0000 (+0000)
Subject: runtime: avoid string allocation in printDebuglog
X-Git-Tag: go1.19beta1~76
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=73587b71a62f7c7a27664a207781dedae223774b;p=gostls13.git

runtime: avoid string allocation in printDebuglog

Either due to a new nowritebarrierrec annotation or a change in escape
analysis, printDebuglog can't be called from sighandler anymore.

Fix this by avoiding a string allocation that's the primary culprit.

Change-Id: Ic84873a453f45852b0443a46597ed3ab8c9443fd
Reviewed-on: https://go-review.googlesource.com/c/go/+/410121
Run-TryBot: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
---

diff --git a/src/runtime/debuglog.go b/src/runtime/debuglog.go
index 7f92a6baf8..ca1a791c93 100644
--- a/src/runtime/debuglog.go
+++ b/src/runtime/debuglog.go
@@ -777,7 +777,8 @@ func printDebugLog() {
 			// Logged before runtimeInitTime was set.
 			pnano = 0
 		}
-		print(string(itoaDiv(tmpbuf[:], uint64(pnano), 9)))
+		pnanoBytes := itoaDiv(tmpbuf[:], uint64(pnano), 9)
+		print(slicebytetostringtmp((*byte)(noescape(unsafe.Pointer(&pnanoBytes[0]))), len(pnanoBytes)))
 		print(" P ", p, "] ")
 
 		for i := 0; s.begin < s.end; i++ {