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>
This commit is contained in:
Stefan Liebler 2025-01-10 12:55:50 -05:00 committed by Siddhesh Poyarekar
parent 2ac7701888
commit 09ea1afec7
3 changed files with 19 additions and 10 deletions

View File

@ -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");

View File

@ -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,
};

View File

@ -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");