selftests/mm: suppress compiler error in liburing check

When building the mm selftests on a system without liburing development
headers, check_config.sh leaks a raw compiler error:

  /tmp/tmp.kIIOIqwe3n.c:2:10: fatal error: liburing.h: No such file or directory
      2 | #include <liburing.h>
        |          ^~~~~~~~~~~~

Since this is an expected failure during the configuration probe,
redirect the compiler output to /dev/null to hide it.

And the build system prints a clear warning when this occurs:

  Warning: missing liburing support. Some tests will be skipped.

Because the user is properly notified about the missing dependency, the
raw compiler error is redundant and only confuse users.

Additionally, update the Makefile to use $(Q) and $(call msg,...) for the
check_config.sh execution.  This aligns the probe with standard kbuild
output formatting, providing a clean "CHK" message instead of printing the
raw command during the build.

Link: https://lore.kernel.org/20260422080446.26020-3-wangli.ahau@gmail.com
Signed-off-by: Li Wang <wangli.ahau@gmail.com>
Tested-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile
index 6195770eba6e3cd71529fd748fba84d2e8d3c38a..18779045b7f695103d0a59a3febf76c23bcf0fb5 100644 (file)
--- a/tools/testing/selftests/mm/Makefile
+++ b/tools/testing/selftests/mm/Makefile
@@ -263,7 +263,8 @@ $(OUTPUT)/migration: LDLIBS += -lnuma
 $(OUTPUT)/rmap: LDLIBS += -lnuma
 
 local_config.mk local_config.h: check_config.sh
-       CC="$(CC)" CFLAGS="$(CFLAGS)" ./check_config.sh
+       $(call msg,CHK,config,$@)
+       $(Q)CC="$(CC)" CFLAGS="$(CFLAGS)" ./check_config.sh
 
 EXTRA_CLEAN += local_config.mk local_config.h
 

diff --git a/tools/testing/selftests/mm/check_config.sh b/tools/testing/selftests/mm/check_config.sh
index b84c82bbf87525b59fa8e720c9d2f5ef3af7cc0c..32beaefe279e5c5ae3e5571caeb804c711637069 100755 (executable)
--- a/tools/testing/selftests/mm/check_config.sh
+++ b/tools/testing/selftests/mm/check_config.sh
@@ -16,7 +16,7 @@ echo "#include <sys/types.h>"        > $tmpfile_c
 echo "#include <liburing.h>"        >> $tmpfile_c
 echo "int func(void) { return 0; }" >> $tmpfile_c
 
-$CC $CFLAGS -c $tmpfile_c -o $tmpfile_o
+$CC $CFLAGS -c $tmpfile_c -o $tmpfile_o >/dev/null 2>&1
 
 if [ -f $tmpfile_o ]; then
     echo "#define LOCAL_CONFIG_HAVE_LIBURING 1"  > $OUTPUT_H_FILE