commit 09ea1afec75ed0d41cb0da27a9df1b8c3dd56ddc
Author: Stefan Liebler <stli@linux.ibm.com>
Date:   Fri Jan 10 12:55:50 2025 -0500

    affinity-inheritance: Overallocate CPU sets
    
    Some kernels on S390 appear to return a CPU affinity mask based on
    configured processors rather than the ones online.  Overallocate the CPU
    set to match that, but operate only on the ones online.
    
    Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
    Co-authored-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

diff --git a/nptl/tst-pthread-affinity-inheritance.c b/nptl/tst-pthread-affinity-inheritance.c
index c020530dd916dea1..153fc904dfe14c9d 100644
--- a/nptl/tst-pthread-affinity-inheritance.c
+++ b/nptl/tst-pthread-affinity-inheritance.c
@@ -34,10 +34,11 @@ set_my_affinity (size_t size, const cpu_set_t *set)
 }
 
 static void
-verify_my_affinity (int nproc, size_t size, const cpu_set_t *expected_set)
+verify_my_affinity (int nproc, int nproc_configured, size_t size,
+		    const cpu_set_t *expected_set)
 {
-  cpu_set_t *set = CPU_ALLOC (nproc);
-  cpu_set_t *xor_set = CPU_ALLOC (nproc);
+  cpu_set_t *set = CPU_ALLOC (nproc_configured);
+  cpu_set_t *xor_set = CPU_ALLOC (nproc_configured);
 
   if (set == NULL || xor_set== NULL)
     FAIL_EXIT1 ("verify_my_affinity: Failed to allocate cpuset: %m\n");
diff --git a/nptl/tst-skeleton-affinity-inheritance.c b/nptl/tst-skeleton-affinity-inheritance.c
index 6de6d9c9428a0c9d..926f49622990e9e4 100644
--- a/nptl/tst-skeleton-affinity-inheritance.c
+++ b/nptl/tst-skeleton-affinity-inheritance.c
@@ -42,6 +42,7 @@
 struct test_param
 {
   int nproc;
+  int nproc_configured;
   cpu_set_t *set;
   size_t size;
   bool entry;
@@ -70,7 +71,8 @@ child_test (void *arg)
   struct test_param *param = arg;
 
   printf ("%d:%d        child\n", getpid (), gettid ());
-  verify_my_affinity (param->nproc, param->size, param->set);
+  verify_my_affinity (param->nproc, param->nproc_configured, param->size,
+		      param->set);
   return NULL;
 }
 
@@ -93,7 +95,8 @@ do_one_test (void *arg)
   else
     {
       /* Verification for the first level.  */
-      verify_my_affinity (param->nproc, param->size, param->set);
+      verify_my_affinity (param->nproc, param->nproc_configured, param->size,
+			  param->set);
 
       /* Launch the second level test, launching CHILD_TEST as a subprocess and
 	 then as a subthread.  Use a different mask to see if it gets
@@ -129,13 +132,17 @@ do_one_test (void *arg)
 static int
 do_test (void)
 {
+  /* Large enough in case the kernel decides to return the larger mask.  This
+     seems to happen on some kernels for S390x.  */
+  int num_configured_cpus = get_nprocs_conf ();
   int num_cpus = get_nprocs ();
 
   struct test_param param =
     {
       .nproc = num_cpus,
-      .set = CPU_ALLOC (num_cpus),
-      .size = CPU_ALLOC_SIZE (num_cpus),
+      .nproc_configured = num_configured_cpus,
+      .set = CPU_ALLOC (num_configured_cpus),
+      .size = CPU_ALLOC_SIZE (num_configured_cpus),
       .entry = true,
     };
 
diff --git a/sysdeps/unix/sysv/linux/tst-sched-affinity-inheritance.c b/sysdeps/unix/sysv/linux/tst-sched-affinity-inheritance.c
index fe0297f743d55e2f..8a42d275fce35e84 100644
--- a/sysdeps/unix/sysv/linux/tst-sched-affinity-inheritance.c
+++ b/sysdeps/unix/sysv/linux/tst-sched-affinity-inheritance.c
@@ -34,10 +34,11 @@ set_my_affinity (size_t size, const cpu_set_t *set)
 }
 
 static void
-verify_my_affinity (int nproc, size_t size, const cpu_set_t *expected_set)
+verify_my_affinity (int nproc, int nproc_configured, size_t size,
+		    const cpu_set_t *expected_set)
 {
-  cpu_set_t *set = CPU_ALLOC (nproc);
-  cpu_set_t *xor_set = CPU_ALLOC (nproc);
+  cpu_set_t *set = CPU_ALLOC (nproc_configured);
+  cpu_set_t *xor_set = CPU_ALLOC (nproc_configured);
 
   if (set == NULL || xor_set== NULL)
     FAIL_EXIT1 ("verify_my_affinity: Failed to allocate cpuset: %m\n");