From 2e7c07f4d10c1b391a7138471c49f4aae3c47d8d Mon Sep 17 00:00:00 2001
From: Ben Noordhuis <info@bnoordhuis.nl>
Date: Thu, 31 Jul 2025 11:54:57 +0200
Subject: [PATCH] linux: handle cgroups cpu.max with limit < period (#4853)

This apparently manifests when one passes `--cpu=.5` to docker because
then /sys/fs/cgroup/cpu.max looks like `50000 100000`, and 50000 divided
by 100000 is zero when using integer math.

Return 1 in that case, indicating there is at least one CPU available.
Returning 0 makes no sense because there is always at least one CPU
available, otherwise the program wouldn't be running.

Fixes: https://github.com/nodejs/node/issues/59200
---
 src/unix/linux.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/unix/linux.c b/src/unix/linux.c
index 1a62d78df..4bfb2d2e7 100644
--- a/src/unix/linux.c
+++ b/src/unix/linux.c
@@ -2363,6 +2363,8 @@ static int uv__get_cgroupv2_constrained_cpu(const char* cgroup,
       goto next;
 
     *quota = limit / period;
+    if (*quota == 0)
+        *quota = 1;
     if (*quota < min_quota)
       min_quota = *quota;