From 58c71d54fc063439fe6fdf1125d3b4a46cd31041 Mon Sep 17 00:00:00 2001
From: Rahat Mahmood <rahat@google.com>
Date: Tue, 15 Nov 2022 13:48:33 -0800
Subject: [PATCH] Disable S/R while rapidly polling control files in cgroups
 tests.

This resulted in too many S/Rs and prevents tasks from being scheduled
and accumulating CPU time.

PiperOrigin-RevId: 488748888
---
 test/util/cgroup_util.cc | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/test/util/cgroup_util.cc b/test/util/cgroup_util.cc
index dca02c6ce..ca9bc4d29 100644
--- a/test/util/cgroup_util.cc
+++ b/test/util/cgroup_util.cc
@@ -102,6 +102,11 @@ PosixError Cgroup::PollControlFileForChangeAfter(
 
   body();
 
+  // The loop below iterates quickly and results in too many save-restore
+  // cycles. This can prevent tasks from being scheduled and incurring the
+  // resource usage this function is often waiting for, resulting in timeouts.
+  const DisableSave ds;
+
   while (true) {
     ASSIGN_OR_RETURN_ERRNO(const int64_t current_value,
                            ReadIntegerControlFile(name));