From a9de5c7f130ceac5d82a413a40e10a8c594af529 Mon Sep 17 00:00:00 2001
From: Erik Gahlin <egahlin@openjdk.org>
Date: Mon, 4 Dec 2023 16:37:33 +0000
Subject: [PATCH] 8315128: jdk/jfr/event/runtime/TestResidentSetSizeEvent.java
 fails with "The size should be less than or equal to peak"

Reviewed-by: stefank, mgronlun
---
 src/hotspot/os/bsd/os_bsd.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/hotspot/os/bsd/os_bsd.cpp b/src/hotspot/os/bsd/os_bsd.cpp
index fc8e0da1a69..18f3cd2b38d 100644
--- a/src/hotspot/os/bsd/os_bsd.cpp
+++ b/src/hotspot/os/bsd/os_bsd.cpp
@@ -2540,7 +2540,9 @@ void os::jfr_report_memory_info() {
     // Send the RSS JFR event
     EventResidentSetSize event;
     event.set_size(info.resident_size);
-    event.set_peak(info.resident_size_max);
+    // We've seen that resident_size_max sometimes trails resident_size with one page.
+    // Make sure we always report size <= peak
+    event.set_peak(MAX2(info.resident_size_max, info.resident_size));
     event.commit();
   } else {
     // Log a warning