diff --git a/src/hotspot/os/aix/os_aix.cpp b/src/hotspot/os/aix/os_aix.cpp
index fb54d36e9c7..87c8770a5b0 100644
--- a/src/hotspot/os/aix/os_aix.cpp
+++ b/src/hotspot/os/aix/os_aix.cpp
@@ -786,10 +786,8 @@ bool os::create_thread(Thread* thread, ThreadType thr_type,
   guarantee(pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED) == 0, "???");
 
   // Make sure we run in 1:1 kernel-user-thread mode.
-  if (os::Aix::on_aix()) {
-    guarantee(pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM) == 0, "???");
-    guarantee(pthread_attr_setinheritsched(&attr, PTHREAD_EXPLICIT_SCHED) == 0, "???");
-  }
+  guarantee(pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM) == 0, "???");
+  guarantee(pthread_attr_setinheritsched(&attr, PTHREAD_EXPLICIT_SCHED) == 0, "???");
 
   // Start in suspended state, and in os::thread_start, wake the thread up.
   guarantee(pthread_attr_setsuspendstate_np(&attr, PTHREAD_CREATE_SUSPENDED_NP) == 0, "???");
@@ -1295,22 +1293,10 @@ void os::print_memory_info(outputStream* st) {
 
   os::Aix::meminfo_t mi;
   if (os::Aix::get_meminfo(&mi)) {
-    if (os::Aix::on_aix()) {
-      st->print_cr("physical total : " SIZE_FORMAT, mi.real_total);
-      st->print_cr("physical free  : " SIZE_FORMAT, mi.real_free);
-      st->print_cr("swap total     : " SIZE_FORMAT, mi.pgsp_total);
-      st->print_cr("swap free      : " SIZE_FORMAT, mi.pgsp_free);
-    } else {
-      // PASE - Numbers are result of QWCRSSTS; they mean:
-      // real_total: Sum of all system pools
-      // real_free: always 0
-      // pgsp_total: we take the size of the system ASP
-      // pgsp_free: size of system ASP times percentage of system ASP unused
-      st->print_cr("physical total     : " SIZE_FORMAT, mi.real_total);
-      st->print_cr("system asp total   : " SIZE_FORMAT, mi.pgsp_total);
-      st->print_cr("%% system asp used : %.2f",
-        mi.pgsp_total ? (100.0f * (mi.pgsp_total - mi.pgsp_free) / mi.pgsp_total) : -1.0f);
-    }
+    st->print_cr("physical total : " SIZE_FORMAT, mi.real_total);
+    st->print_cr("physical free  : " SIZE_FORMAT, mi.real_free);
+    st->print_cr("swap total     : " SIZE_FORMAT, mi.pgsp_total);
+    st->print_cr("swap free      : " SIZE_FORMAT, mi.pgsp_free);
   }
   st->cr();
 
@@ -2420,9 +2406,7 @@ void os::init(void) {
   }
 
   // Reset the perfstat information provided by ODM.
-  if (os::Aix::on_aix()) {
-    libperfstat::perfstat_reset();
-  }
+  libperfstat::perfstat_reset();
 
   // Now initialize basic system properties. Note that for some of the values we
   // need libperfstat etc.
@@ -2943,9 +2927,7 @@ void os::Aix::initialize_libo4() {
   }
 }
 
-// AIX: initialize the libperfstat library.
 void os::Aix::initialize_libperfstat() {
-  assert(os::Aix::on_aix(), "AIX only");
   if (!libperfstat::init()) {
     trcVerbose("libperfstat initialization failed.");
     assert(false, "libperfstat initialization failed");
diff --git a/src/hotspot/os/aix/os_aix.hpp b/src/hotspot/os/aix/os_aix.hpp
index a1db2b2be3c..22fb5327bf9 100644
--- a/src/hotspot/os/aix/os_aix.hpp
+++ b/src/hotspot/os/aix/os_aix.hpp
@@ -1,6 +1,6 @@
 /*
- * Copyright (c) 1999, 2023, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2013, 2023 SAP SE. All rights reserved.
+ * Copyright (c) 1999, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2024 SAP SE. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -101,13 +101,6 @@ class os::Aix {
     return _on_pase ? true : false;
   }
 
-  // Function returns true if we run on AIX, false if we run on OS/400
-  // (pase).
-  static bool on_aix() {
-    assert(_on_pase != -1, "not initialized");
-    return _on_pase ? false : true;
-  }
-
   // Get 4 byte AIX kernel version number:
   // highest 2 bytes: Version, Release
   // if available: lowest 2 bytes: Tech Level, Service Pack.
@@ -130,11 +123,6 @@ class os::Aix {
     return on_pase() && os_version_short() <= 0x0504;
   }
 
-  // Convenience method: returns true if running on AIX 5.3 or older.
-  static bool on_aix_53_or_older() {
-    return on_aix() && os_version_short() <= 0x0503;
-  }
-
   // Returns true if we run in SPEC1170 compliant mode (XPG_SUS_ENV=ON).
   static bool xpg_sus_mode() {
     assert(_xpg_sus_mode != -1, "not initialized");