1 files changed, 21 insertions, 3 deletions
diff --git a/test/syscalls/linux/itimer.cc b/test/syscalls/linux/itimer.cc
index 930d2b940..e397d5f57 100644
--- a/test/syscalls/linux/itimer.cc
+++ b/test/syscalls/linux/itimer.cc
@@ -246,7 +246,7 @@ int TestSIGPROFFairness(absl::Duration sleep) {
 
   // The number of samples on the main thread should be very low as it did
   // nothing.
-  TEST_CHECK(result.main_thread_samples < 60);
+  TEST_CHECK(result.main_thread_samples < 80);
 
   // Both workers should get roughly equal number of samples.
   TEST_CHECK(result.worker_samples.size() == 2);
@@ -267,6 +267,20 @@ int TestSIGPROFFairness(absl::Duration sleep) {
 // Random save/restore is disabled as it introduces additional latency and
 // unpredictable distribution patterns.
 TEST(ItimerTest, DeliversSIGPROFToThreadsRoughlyFairlyActive_NoRandomSave) {
+  // On the KVM and ptrace platforms, switches between sentry and application
+  // context are sometimes extremely slow, causing the itimer to send SIGPROF to
+  // a thread that either already has one pending or has had SIGPROF delivered,
+  // but hasn't handled it yet (and thus therefore still has SIGPROF masked). In
+  // either case, since itimer signals are group-directed, signal sending falls
+  // back to notifying the thread group leader. ItimerSignalTest() fails if "too
+  // many" signals are delivered to the thread group leader, so these tests are
+  // flaky on these platforms.
+  //
+  // TODO(b/143247272): Clarify why context switches are so slow on KVM.
+  const auto gvisor_platform = GvisorPlatform();
+  SKIP_IF(gvisor_platform == Platform::kKVM ||
+          gvisor_platform == Platform::kPtrace);
+
   pid_t child;
   int execve_errno;
   auto kill = ASSERT_NO_ERRNO_AND_VALUE(
@@ -288,6 +302,11 @@ TEST(ItimerTest, DeliversSIGPROFToThreadsRoughlyFairlyActive_NoRandomSave) {
 // Random save/restore is disabled as it introduces additional latency and
 // unpredictable distribution patterns.
 TEST(ItimerTest, DeliversSIGPROFToThreadsRoughlyFairlyIdle_NoRandomSave) {
+  // See comment in DeliversSIGPROFToThreadsRoughlyFairlyActive.
+  const auto gvisor_platform = GvisorPlatform();
+  SKIP_IF(gvisor_platform == Platform::kKVM ||
+          gvisor_platform == Platform::kPtrace);
+
   pid_t child;
   int execve_errno;
   auto kill = ASSERT_NO_ERRNO_AND_VALUE(
@@ -343,6 +362,5 @@ int main(int argc, char** argv) {
   }
 
   gvisor::testing::TestInit(&argc, &argv);
-
-  return RUN_ALL_TESTS();
+  return gvisor::testing::RunAllTests();
 }