From 447a063f3c6583ed8e1946900493c1343b1daaef Mon Sep 17 00:00:00 2001
From: Alex Chi Z <iskyzh@gmail.com>
Date: Wed, 24 Apr 2024 11:09:23 -0400
Subject: [PATCH] fix(metrics): correct maxrss metrics on macos (#7487)

macOS max_rss is in bytes, while Linux is in kilobytes.
https://stackoverflow.com/a/59915669

---------

Signed-off-by: Alex Chi Z <chi@neon.tech>
---
 libs/metrics/src/lib.rs | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/libs/metrics/src/lib.rs b/libs/metrics/src/lib.rs
index 2cf3cdeaa7..8e0dbe6ce4 100644
--- a/libs/metrics/src/lib.rs
+++ b/libs/metrics/src/lib.rs
@@ -256,7 +256,16 @@ fn update_rusage_metrics() {
     DISK_IO_BYTES
         .with_label_values(&["write"])
         .set(rusage_stats.ru_oublock * BYTES_IN_BLOCK);
-    MAXRSS_KB.set(rusage_stats.ru_maxrss);
+
+    // On macOS, the unit of maxrss is bytes; on Linux, it's kilobytes. https://stackoverflow.com/a/59915669
+    #[cfg(target_os = "macos")]
+    {
+        MAXRSS_KB.set(rusage_stats.ru_maxrss / 1024);
+    }
+    #[cfg(not(target_os = "macos"))]
+    {
+        MAXRSS_KB.set(rusage_stats.ru_maxrss);
+    }
 }
 
 fn get_rusage_stats() -> libc::rusage {