[ping][PATCH v1.1] tests: Verify inheritance of cpu affinity

[Siddhesh Poyarekar]

Ping!

On 2024-12-17 20:17, Siddhesh Poyarekar wrote:
> Add a couple of tests to verify that CPU affinity set using
> sched_setaffinity and pthread_setaffinity_np are inherited by a child
> process and child thread.
> 
> Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
> ---
> Resending because I accidentally sent the previous one to the ungetc
> thread.
> 
>   nptl/Makefile                                 |   1 +
>   nptl/tst-pthread-affinity-inheritance.c       |  71 ++++++++
>   nptl/tst-skeleton-affinity-inheritance.c      | 152 ++++++++++++++++++
>   sysdeps/unix/sysv/linux/Makefile              |   1 +
>   .../linux/tst-sched-affinity-inheritance.c    |  71 ++++++++
>   5 files changed, 296 insertions(+)
>   create mode 100644 nptl/tst-pthread-affinity-inheritance.c
>   create mode 100644 nptl/tst-skeleton-affinity-inheritance.c
>   create mode 100644 sysdeps/unix/sysv/linux/tst-sched-affinity-inheritance.c
> 
> diff --git a/nptl/Makefile b/nptl/Makefile
> index 88077e27bb..429b8e3c33 100644
> --- a/nptl/Makefile
> +++ b/nptl/Makefile
> @@ -313,6 +313,7 @@ tests = \
>     tst-mutexpi11 \
>     tst-mutexpi12 \
>     tst-once5 \
> +  tst-pthread-affinity-inheritance \
>     tst-pthread-attr-affinity \
>     tst-pthread-attr-affinity-fail \
>     tst-pthread-attr-sigmask \
> diff --git a/nptl/tst-pthread-affinity-inheritance.c b/nptl/tst-pthread-affinity-inheritance.c
> new file mode 100644
> index 0000000000..c020530dd9
> --- /dev/null
> +++ b/nptl/tst-pthread-affinity-inheritance.c
> @@ -0,0 +1,71 @@
> +/* CPU Affinity inheritance test - pthread_{gs}etaffinity_np.
> +   Copyright The GNU Toolchain Authors.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <https://www.gnu.org/licenses/>.  */
> +
> +/* See top level comment in nptl/tst-skeleton-affinity-inheritance.c for a
> +   description of this test.  */
> +#include <pthread.h>
> +#include <sched.h>
> +#include <stdio.h>
> +#include <string.h>
> +#include <support/check.h>
> +
> +static void
> +set_my_affinity (size_t size, const cpu_set_t *set)
> +{
> +  int ret = pthread_setaffinity_np (pthread_self (), size, set);
> +
> +  if (ret != 0)
> +    FAIL ("pthread_setaffinity_np returned %d (%s)", ret, strerror (ret));
> +}
> +
> +static void
> +verify_my_affinity (int nproc, size_t size, const cpu_set_t *expected_set)
> +{
> +  cpu_set_t *set = CPU_ALLOC (nproc);
> +  cpu_set_t *xor_set = CPU_ALLOC (nproc);
> +
> +  if (set == NULL || xor_set== NULL)
> +    FAIL_EXIT1 ("verify_my_affinity: Failed to allocate cpuset: %m\n");
> +
> +  int ret = pthread_getaffinity_np (pthread_self (), size, set);
> +  if (ret != 0)
> +    FAIL ("pthread_getaffinity_np returned %d (%s)", ret, strerror (ret));
> +
> +  CPU_XOR_S (size, xor_set, expected_set, set);
> +
> +  int cpucount = CPU_COUNT_S (size, xor_set);
> +
> +  if (cpucount > 0)
> +    {
> +      FAIL ("Affinity mask not inherited, "
> +	    "following %d CPUs mismatched in the expected and actual sets: ",
> +	    cpucount);
> +      for (int cur = 0; cur < nproc && cpucount >= 0; cur++)
> +	if (CPU_ISSET_S (size, cur, xor_set))
> +	  {
> +	    printf ("%d ", cur);
> +	    cpucount--;
> +	  }
> +      printf ("\n");
> +    }
> +
> +  CPU_FREE (set);
> +  CPU_FREE (xor_set);
> +}
> +
> +#include "tst-skeleton-affinity-inheritance.c"
> diff --git a/nptl/tst-skeleton-affinity-inheritance.c b/nptl/tst-skeleton-affinity-inheritance.c
> new file mode 100644
> index 0000000000..6de6d9c942
> --- /dev/null
> +++ b/nptl/tst-skeleton-affinity-inheritance.c
> @@ -0,0 +1,152 @@
> +/* CPU Affinity inheritance test - common infrastructure.
> +   Copyright The GNU Toolchain Authors.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <https://www.gnu.org/licenses/>.  */
> +
> +/* The general idea of this test is to verify that the set of CPUs assigned to
> +   a task gets inherited by a child (thread or process) of that task.  This is
> +   a framework that is included by specific APIs for the test, e.g.
> +   sched_getaffinity/sched_setaffinity and
> +   pthread_setaffinity_np/pthread_getaffinity_np.  This is a framework, actual
> +   tests entry points are in nptl/tst-pthread-affinity-inheritance.c and
> +   sysdeps/unix/sysv/linux/tst-sched-affinity-inheritance.c.
> +
> +   There are two levels to the test with two different CPU masks.  The first
> +   level verifies that the affinity set on the main process is inherited by its
> +   children subprocess or thread.  The second level verifies that a subprocess
> +   or subthread passes on its affinity to their respective subprocess or
> +   subthread.  We set a slightly different mask in both levels to ensure that
> +   they're both inherited.  */
> +
> +#include <errno.h>
> +#include <stdio.h>
> +#include <support/test-driver.h>
> +#include <support/xthread.h>
> +#include <support/xunistd.h>
> +#include <sys/sysinfo.h>
> +#include <sys/wait.h>
> +
> +struct test_param
> +{
> +  int nproc;
> +  cpu_set_t *set;
> +  size_t size;
> +  bool entry;
> +};
> +
> +void __attribute__((noinline))
> +set_cpu_mask (struct test_param *param, bool entry)
> +{
> +  int cpus = param->nproc;
> +
> +  /* Less CPUS for the first level, if that's possible.  */
> +  if (entry && cpus > 1)
> +    cpus--;
> +
> +  CPU_ZERO_S (param->size, param->set);
> +  while (cpus > 0)
> +    CPU_SET_S (--cpus, param->size, param->set);
> +
> +  if (CPU_COUNT_S (param->size, param->set) == 0)
> +    FAIL_EXIT1 ("Failed to add any CPUs to the affinity set\n");
> +}
> +
> +static void *
> +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);
> +  return NULL;
> +}
> +
> +void *
> +do_one_test (void *arg)
> +{
> +  void *(*child) (void *) = NULL;
> +  struct test_param *param = arg;
> +  bool entry = param->entry;
> +
> +  if (entry)
> +    {
> +      printf ("%d:%d Start test run\n", getpid (), gettid ());
> +      /* First level: Reenter as a subprocess and then as a subthread.  */
> +      child = do_one_test;
> +      set_cpu_mask (param, true);
> +      set_my_affinity (param->size, param->set);
> +      param->entry = false;
> +    }
> +  else
> +    {
> +      /* Verification for the first level.  */
> +      verify_my_affinity (param->nproc, 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
> +	 inherited.  */
> +      child = child_test;
> +      set_cpu_mask (param, false);
> +      set_my_affinity (param->size, param->set);
> +    }
> +
> +  /* Verify that a child of a thread/process inherits the affinity mask.  */
> +  printf ("%d:%d%sdo_one_test: fork\n", getpid (), gettid (),
> +	  entry ? " " : "    ");
> +  int pid = xfork ();
> +
> +  if (pid == 0)
> +    {
> +      child (param);
> +      return NULL;
> +    }
> +
> +  xwaitpid (pid, NULL, 0);
> +
> +  /* Verify that a subthread of a thread/process inherits the affinity
> +     mask.  */
> +  printf ("%d:%d%sdo_one_test: thread\n", getpid (), gettid (),
> +	  entry ? " " : "    ");
> +  pthread_t t = xpthread_create (NULL, child, param);
> +  xpthread_join (t);
> +
> +  return NULL;
> +}
> +
> +static int
> +do_test (void)
> +{
> +  int num_cpus = get_nprocs ();
> +
> +  struct test_param param =
> +    {
> +      .nproc = num_cpus,
> +      .set = CPU_ALLOC (num_cpus),
> +      .size = CPU_ALLOC_SIZE (num_cpus),
> +      .entry = true,
> +    };
> +
> +  if (param.set == NULL)
> +    FAIL_EXIT1 ("error: CPU_ALLOC (%d) failed\n", num_cpus);
> +
> +  do_one_test (&param);
> +
> +  CPU_FREE (param.set);
> +
> +  return 0;
> +}
> +
> +#include <support/test-driver.c>
> diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
> index eb9c697ce5..1be3195ecf 100644
> --- a/sysdeps/unix/sysv/linux/Makefile
> +++ b/sysdeps/unix/sysv/linux/Makefile
> @@ -226,6 +226,7 @@ tests += \
>     tst-process_mrelease \
>     tst-quota \
>     tst-rlimit-infinity \
> +  tst-sched-affinity-inheritance \
>     tst-sched_setattr \
>     tst-scm_rights \
>     tst-sigtimedwait \
> diff --git a/sysdeps/unix/sysv/linux/tst-sched-affinity-inheritance.c b/sysdeps/unix/sysv/linux/tst-sched-affinity-inheritance.c
> new file mode 100644
> index 0000000000..fe0297f743
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/tst-sched-affinity-inheritance.c
> @@ -0,0 +1,71 @@
> +/* CPU Affinity inheritance test - sched_{gs}etaffinity.
> +   Copyright The GNU Toolchain Authors.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <https://www.gnu.org/licenses/>.  */
> +
> +/* See top level comment in nptl/tst-skeleton-affinity-inheritance.c for a
> +   description of this test.  */
> +
> +#include <sched.h>
> +#include <string.h>
> +#include <stdio.h>
> +#include <support/check.h>
> +
> +static void
> +set_my_affinity (size_t size, const cpu_set_t *set)
> +{
> +  int ret = sched_setaffinity (0, size, set);
> +
> +  if (ret != 0)
> +    FAIL ("sched_setaffinity returned %d (%s)", ret, strerror (ret));
> +}
> +
> +static void
> +verify_my_affinity (int nproc, size_t size, const cpu_set_t *expected_set)
> +{
> +  cpu_set_t *set = CPU_ALLOC (nproc);
> +  cpu_set_t *xor_set = CPU_ALLOC (nproc);
> +
> +  if (set == NULL || xor_set== NULL)
> +    FAIL_EXIT1 ("verify_my_affinity: Failed to allocate cpuset: %m\n");
> +
> +  int ret = sched_getaffinity (0, size, set);
> +  if (ret != 0)
> +    FAIL ("sched_getaffinity returned %d (%s)", ret, strerror (ret));
> +
> +  CPU_XOR_S (size, xor_set, expected_set, set);
> +
> +  int cpucount = CPU_COUNT_S (size, xor_set);
> +
> +  if (cpucount > 0)
> +    {
> +      FAIL ("Affinity mask not inherited, "
> +	    "following %d CPUs mismatched in the expected and actual sets:\n",
> +	    cpucount);
> +      for (int cur = 0; cur < nproc && cpucount >= 0; cur++)
> +	if (CPU_ISSET_S (size, cur, xor_set))
> +	  {
> +	    printf ("%d ", cur);
> +	    cpucount--;
> +	  }
> +      printf ("\n");
> +    }
> +
> +  CPU_FREE (set);
> +  CPU_FREE (xor_set);
> +}
> +
> +#include <nptl/tst-skeleton-affinity-inheritance.c>