[PATCH v2] selftests/futex: Compile also on libnuma < 2.0.16

[Sebastian Andrzej Siewior <bigeasy@linutronix.de>]

After using numa_set_mempolicy_home_node() the test fails to compile on
systems with libnuma library versioned lower than 2.0.16.

In order to allow lower library version add a pkg-config related check
and exclude that part of the code. Without the proper MPOL setup it
can't be tested.

Make a total number of tests two. The first one is the first batch and
the second is the MPOL related one. The goal is to let the user know if
it has been skipped due to library limitation.

Remove test_futex_mpol(), it was unused and it is now complained by the
compiler if the part is not compiled.

Fixes: 0ecb4232fc65e ("selftests/futex: Set the home_node in futex_numa_mpol")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202507150858.bedaf012-lkp@intel.com
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
v1…v2:
   - typo in LIBNUMA fixed
   - avoid __maybe_unused

 .../selftests/futex/functional/Makefile       |  5 ++++-
 .../futex/functional/futex_numa_mpol.c        | 21 +++++++++----------
 2 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/tools/testing/selftests/futex/functional/Makefile b/tools/testing/selftests/futex/functional/Makefile
index 8cfb87f7f7c50..6f7887f585afb 100644
--- a/tools/testing/selftests/futex/functional/Makefile
+++ b/tools/testing/selftests/futex/functional/Makefile
@@ -1,6 +1,9 @@
 # SPDX-License-Identifier: GPL-2.0
+PKG_CONFIG ?= pkg-config
+LIBNUMA_TEST = $(shell sh -c "$(PKG_CONFIG) numa --atleast-version 2.0.16 > /dev/null 2>&1 && echo SUFFICIENT || echo NO")
+
 INCLUDES := -I../include -I../../ $(KHDR_INCLUDES)
-CFLAGS := $(CFLAGS) -g -O2 -Wall -pthread $(INCLUDES) $(KHDR_INCLUDES)
+CFLAGS := $(CFLAGS) -g -O2 -Wall -pthread $(INCLUDES) $(KHDR_INCLUDES) -DLIBNUMA_VER_$(LIBNUMA_TEST)=1
 LDLIBS := -lpthread -lrt -lnuma
 
 LOCAL_HDRS := \
diff --git a/tools/testing/selftests/futex/functional/futex_numa_mpol.c b/tools/testing/selftests/futex/functional/futex_numa_mpol.c
index a9ecfb2d3932a..120ea7d5a3cf9 100644
--- a/tools/testing/selftests/futex/functional/futex_numa_mpol.c
+++ b/tools/testing/selftests/futex/functional/futex_numa_mpol.c
@@ -125,11 +125,6 @@ static void test_futex(void *futex_ptr, int must_fail)
 	__test_futex(futex_ptr, must_fail, FUTEX2_SIZE_U32 | FUTEX_PRIVATE_FLAG | FUTEX2_NUMA);
 }
 
-static void test_futex_mpol(void *futex_ptr, int must_fail)
-{
-	__test_futex(futex_ptr, must_fail, FUTEX2_SIZE_U32 | FUTEX_PRIVATE_FLAG | FUTEX2_NUMA | FUTEX2_MPOL);
-}
-
 static void usage(char *prog)
 {
 	printf("Usage: %s\n", prog);
@@ -142,7 +137,7 @@ static void usage(char *prog)
 int main(int argc, char *argv[])
 {
 	struct futex32_numa *futex_numa;
-	int mem_size, i;
+	int mem_size;
 	void *futex_ptr;
 	int c;
 
@@ -165,7 +160,7 @@ int main(int argc, char *argv[])
 	}
 
 	ksft_print_header();
-	ksft_set_plan(1);
+	ksft_set_plan(2);
 
 	mem_size = sysconf(_SC_PAGE_SIZE);
 	futex_ptr = mmap(NULL, mem_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
@@ -201,8 +196,11 @@ int main(int argc, char *argv[])
 	ksft_print_msg("Memory back to RW\n");
 	test_futex(futex_ptr, 0);
 
+	ksft_test_result_pass("futex2 memory boundarie tests passed\n");
+
 	/* MPOL test. Does not work as expected */
-	for (i = 0; i < 4; i++) {
+#ifdef LIBNUMA_VER_SUFFICIENT
+	for (int i = 0; i < 4; i++) {
 		unsigned long nodemask;
 		int ret;
 
@@ -221,15 +219,16 @@ int main(int argc, char *argv[])
 			ret = futex2_wake(futex_ptr, 0, FUTEX2_SIZE_U32 | FUTEX_PRIVATE_FLAG | FUTEX2_NUMA | FUTEX2_MPOL);
 			if (ret < 0)
 				ksft_test_result_fail("Failed to wake 0 with MPOL: %m\n");
-			if (0)
-				test_futex_mpol(futex_numa, 0);
 			if (futex_numa->numa != i) {
 				ksft_exit_fail_msg("Returned NUMA node is %d expected %d\n",
 						   futex_numa->numa, i);
 			}
 		}
 	}
-	ksft_test_result_pass("NUMA MPOL tests passed\n");
+	ksft_test_result_pass("futex2 MPOL hints test passed\n");
+#else
+	ksft_test_result_skip("futex2 MPOL hints test requires libnuma 2.0.16+\n");
+#endif
 	ksft_finished();
 	return 0;
 }
-- 
2.50.1