[LTP] [PATCH 0/2] Create new library helper: tst_getconf

[LTP] [PATCH 0/2] Create new library helper: tst_getconf

[=?unknown-8bit?q?Myl=C3=A8ne?= Josserand]

Hello everyone,

I previously sent a patch to fix the issue I got with "getconf"
which may not available in some embedded systems [1][2].

Cyril proposed to implement a tst_getconf to implement subset of
variables [3]. Based on his remark, I implemented it and I use "sysconf"
function that allows to retrieve configuration's variables at runtime[4].
Thanks to that, we are not depending anymore on a binary and we can retrieve
variables such as PAGESIZE or _SC_NPROCESSORS_ONLN.

The first patch adds this new library and the second patch replaces
"getconf" by "tst_getconf" in all the tests.

If you have any review/remark, do not hesitate!
Thank you in advance,
Mylène

[1]: http://lists.linux.it/pipermail/ltp/2018-April/007836.html
[2]: http://lists.linux.it/pipermail/ltp/2018-April/007835.html
[3]: http://lists.linux.it/pipermail/ltp/2018-April/007842.html
[4]: http://man7.org/linux/man-pages/man3/sysconf.3.html

Mylène Josserand (2):
  testcase: lib: Create tst_getconf to replace "getconf"
  testcases: Replace "getconf" by "tst_getconf"

 doc/test-writing-guidelines.txt                    | 14 ++++++
 testcases/commands/du/du01.sh                      |  2 +-
 testcases/commands/mkswap/mkswap01.sh              |  2 +-
 .../controllers/cpuset/cpuset_regression_test.sh   |  2 +-
 .../memcg/control/memcg_control_test.sh            |  2 +-
 .../controllers/memcg/functional/memcg_lib.sh      |  4 +-
 testcases/kernel/numa/numa01.sh                    |  2 +-
 testcases/lib/.gitignore                           |  1 +
 testcases/lib/Makefile                             |  3 +-
 testcases/lib/test.sh                              |  4 +-
 testcases/lib/tst_getconf.c                        | 57 ++++++++++++++++++++++
 11 files changed, 83 insertions(+), 10 deletions(-)
 create mode 100644 testcases/lib/tst_getconf.c

-- 
2.11.0

[LTP] [PATCH 1/2] testcase: lib: Create tst_getconf to replace "getconf"

[=?unknown-8bit?q?Myl=C3=A8ne?= Josserand]

In some system, "getconf" application may not be installed.
Some tests are using it to retrieve some variables such as the
page size (PAGESIZE).

Create a tst_getconf binary that use sysconf() function to retrieve
these variables instead of relying on "getconf" application that
may not be available.
Add also this new helper in the documentation.

Example:
pagesize=`tst_getconf PAGESIZE`

Signed-off-by: Mylène Josserand <mylene.josserand@bootlin.com>
---
 doc/test-writing-guidelines.txt | 14 ++++++++++
 testcases/lib/.gitignore        |  1 +
 testcases/lib/Makefile          |  3 ++-
 testcases/lib/tst_getconf.c     | 57 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 74 insertions(+), 1 deletion(-)
 create mode 100644 testcases/lib/tst_getconf.c

diff --git a/doc/test-writing-guidelines.txt b/doc/test-writing-guidelines.txt
index fb7dcb591..e42451fae 100644
--- a/doc/test-writing-guidelines.txt
+++ b/doc/test-writing-guidelines.txt
@@ -1630,6 +1630,20 @@ passed directly to the script in '$1', '$2', ..., '$n'.
 2.3.4 Usefull library functions
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
+Retrieving configuration variables
+++++++++++++++++++++++++++++++++++
+
+You may need to retrieve some variable configuration such as PAGESIZE.
+There is "getconf" application that allows that but as some system may not
+have it, a "tst_getconf" library allows to retrieve these variables by using
+"sysconf()" function.
+
+[source,sh]
+-------------------------------------------------------------------------------
+# retrieve PAGESIZE
+pagesize=`tst_getconf PAGESIZE`
+-------------------------------------------------------------------------------
+
 Sleeping for subsecond intervals
 ++++++++++++++++++++++++++++++++
 
diff --git a/testcases/lib/.gitignore b/testcases/lib/.gitignore
index f36ed99fa..997940006 100644
--- a/testcases/lib/.gitignore
+++ b/testcases/lib/.gitignore
@@ -7,3 +7,4 @@
 /tst_net_iface_prefix
 /tst_net_ip_prefix
 /tst_net_vars
+/tst_getconf
\ No newline at end of file
diff --git a/testcases/lib/Makefile b/testcases/lib/Makefile
index 398150ae0..77b7b2ef1 100644
--- a/testcases/lib/Makefile
+++ b/testcases/lib/Makefile
@@ -27,6 +27,7 @@ include $(top_srcdir)/include/mk/testcases.mk
 INSTALL_TARGETS		:= *.sh
 
 MAKE_TARGETS		:= tst_sleep tst_random tst_checkpoint tst_rod tst_kvcmp\
-			   tst_device tst_net_iface_prefix tst_net_ip_prefix tst_net_vars
+			   tst_device tst_net_iface_prefix tst_net_ip_prefix tst_net_vars\
+			   tst_getconf
 
 include $(top_srcdir)/include/mk/generic_leaf_target.mk
diff --git a/testcases/lib/tst_getconf.c b/testcases/lib/tst_getconf.c
new file mode 100644
index 000000000..72abcc413
--- /dev/null
+++ b/testcases/lib/tst_getconf.c
@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2018 Mylène Josserand <mylene.josserand@bootlin.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+
+static void print_help(void)
+{
+	printf("Usage: tst_getconf variable\n\n");
+	printf("       variable: can be PAGESIZE or _NPROCESSORS_ONLN (for the moment)\n");
+	printf("example: tst_getconf PAGESIZE\n");
+}
+
+int main(int argc, char *argv[])
+{
+	int opt;
+
+	while ((opt = getopt(argc, argv, ":h")) != -1) {
+		switch (opt) {
+		case 'h':
+			print_help();
+			return 0;
+		default:
+			print_help();
+			return 1;
+		}
+	}
+
+	if (optind >= argc) {
+		fprintf(stderr, "ERROR: Expected variable argument\n\n");
+		print_help();
+		return 1;
+	}
+
+	if (!strcmp(argv[optind], "_NPROCESSORS_ONLN"))
+		printf("%ld", sysconf(_SC_NPROCESSORS_ONLN));
+	else if (!strcmp(argv[optind],"PAGESIZE"))
+		printf("%ld", sysconf(_SC_PAGE_SIZE));
+
+	return 0;
+}
-- 
2.11.0

[LTP] [PATCH 2/2] testcases: Replace "getconf" by "tst_getconf"

[=?unknown-8bit?q?Myl=C3=A8ne?= Josserand]

Now that tst_getconf is available to use "sysconf()" function
instead of relying on the application "getconf", let's convert
all the tests to it.

Signed-off-by: Mylène Josserand <mylene.josserand@bootlin.com>
---
 testcases/commands/du/du01.sh                                    | 2 +-
 testcases/commands/mkswap/mkswap01.sh                            | 2 +-
 testcases/kernel/controllers/cpuset/cpuset_regression_test.sh    | 2 +-
 testcases/kernel/controllers/memcg/control/memcg_control_test.sh | 2 +-
 testcases/kernel/controllers/memcg/functional/memcg_lib.sh       | 4 ++--
 testcases/kernel/numa/numa01.sh                                  | 2 +-
 testcases/lib/test.sh                                            | 4 ++--
 7 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/testcases/commands/du/du01.sh b/testcases/commands/du/du01.sh
index ed1df568f..c75068255 100755
--- a/testcases/commands/du/du01.sh
+++ b/testcases/commands/du/du01.sh
@@ -73,7 +73,7 @@ du_test()
 }
 
 block_size=512
-page_size=$(getconf PAGESIZE)
+page_size=$(tst_getconf PAGESIZE)
 if [ "$page_size" -lt 1024 ]; then
 	tst_brk TBROK "Page size < 1024"
 fi
diff --git a/testcases/commands/mkswap/mkswap01.sh b/testcases/commands/mkswap/mkswap01.sh
index 1c01c86b2..743db4c1a 100755
--- a/testcases/commands/mkswap/mkswap01.sh
+++ b/testcases/commands/mkswap/mkswap01.sh
@@ -29,7 +29,7 @@ setup()
 {
 	UUID=`uuidgen`
 
-	PAGE_SIZE=`getconf PAGE_SIZE`
+	PAGE_SIZE=`tst_getconf PAGE_SIZE`
 
 	# Here get the size of the device and align it down to be the
 	# multiple of $PAGE_SIZE and use that as the size for testing.
diff --git a/testcases/kernel/controllers/cpuset/cpuset_regression_test.sh b/testcases/kernel/controllers/cpuset/cpuset_regression_test.sh
index 4a104a3ad..72a2a944c 100755
--- a/testcases/kernel/controllers/cpuset/cpuset_regression_test.sh
+++ b/testcases/kernel/controllers/cpuset/cpuset_regression_test.sh
@@ -34,7 +34,7 @@ setup()
 		tst_brkm TCONF "Test must be run with kernel 3.18.0 or newer"
 	fi
 
-	local cpu_num=$(getconf _NPROCESSORS_ONLN)
+	local cpu_num=$(tst_getconf _NPROCESSORS_ONLN)
 	if [ $cpu_num -lt 2 ]; then
 		tst_brkm TCONF "We need 2 cpus@least to have test"
 	fi
diff --git a/testcases/kernel/controllers/memcg/control/memcg_control_test.sh b/testcases/kernel/controllers/memcg/control/memcg_control_test.sh
index 1d158729c..4d9f1bb5d 100644
--- a/testcases/kernel/controllers/memcg/control/memcg_control_test.sh
+++ b/testcases/kernel/controllers/memcg/control/memcg_control_test.sh
@@ -41,7 +41,7 @@ export TST_COUNT=0
 export TMP=${TMP:-/tmp}
 cd $TMP
 
-PAGE_SIZE=$(getconf PAGESIZE)
+PAGE_SIZE=$(tst_getconf PAGESIZE)
 
 TOT_MEM_LIMIT=$PAGE_SIZE
 ACTIVE_MEM_LIMIT=$PAGE_SIZE
diff --git a/testcases/kernel/controllers/memcg/functional/memcg_lib.sh b/testcases/kernel/controllers/memcg/functional/memcg_lib.sh
index 6a6af853b..cd16dc685 100755
--- a/testcases/kernel/controllers/memcg/functional/memcg_lib.sh
+++ b/testcases/kernel/controllers/memcg/functional/memcg_lib.sh
@@ -29,9 +29,9 @@ if [ "x$(grep -w memory /proc/cgroups | cut -f4)" != "x1" ]; then
 	tst_brkm TCONF "Kernel does not support the memory resource controller"
 fi
 
-PAGESIZE=$(getconf PAGESIZE)
+PAGESIZE=$(tst_getconf PAGESIZE)
 if [ $? -ne 0 ]; then
-	tst_brkm TBROK "getconf PAGESIZE failed"
+	tst_brkm TBROK "tst_getconf PAGESIZE failed"
 fi
 
 HUGEPAGESIZE=$(awk '/Hugepagesize/ {print $2}' /proc/meminfo)
diff --git a/testcases/kernel/numa/numa01.sh b/testcases/kernel/numa/numa01.sh
index 27a2f2f7c..65e9b7dd5 100755
--- a/testcases/kernel/numa/numa01.sh
+++ b/testcases/kernel/numa/numa01.sh
@@ -83,7 +83,7 @@ wait_for_support_numa()
 setup()
 {
 	export MB=$((1024*1024))
-	export PAGE_SIZE=$(getconf PAGE_SIZE)
+	export PAGE_SIZE=$(tst_getconf PAGE_SIZE)
 	export HPAGE_SIZE=$(awk '/Hugepagesize:/ {print $2}' /proc/meminfo)
 
 	total_nodes=0
diff --git a/testcases/lib/test.sh b/testcases/lib/test.sh
index bce9893a9..650712181 100644
--- a/testcases/lib/test.sh
+++ b/testcases/lib/test.sh
@@ -421,9 +421,9 @@ fi
 if [ "$TST_NEEDS_CHECKPOINTS" = "1" ]; then
 	LTP_IPC_PATH="/dev/shm/ltp_${TCID}_$$"
 
-	LTP_IPC_SIZE=$(getconf PAGESIZE)
+	LTP_IPC_SIZE=$(tst_getconf PAGESIZE)
 	if [ $? -ne 0 ]; then
-		tst_brkm TBROK "getconf PAGESIZE failed"
+		tst_brkm TBROK "tst_getconf PAGESIZE failed"
 	fi
 
 	ROD_SILENT dd if=/dev/zero of="$LTP_IPC_PATH" bs="$LTP_IPC_SIZE" count=1
-- 
2.11.0

[LTP] [PATCH 1/2] testcase: lib: Create tst_getconf to replace "getconf"

[Li Wang]

Mylène Josserand <mylene.josserand@bootlin.com> wrote:

> In some system, "getconf" application may not be installed.
> Some tests are using it to retrieve some variables such as the
> page size (PAGESIZE).
>
> Create a tst_getconf binary that use sysconf() function to retrieve
> these variables instead of relying on "getconf" application that
> may not be available.
> Add also this new helper in the documentation.
>
> Example:
> pagesize=`tst_getconf PAGESIZE`
>
> Signed-off-by: Mylène Josserand <mylene.josserand@bootlin.com>
> ​[...]
> +
> +#include <stdio.h>
> +#include <unistd.h>
> +#include <string.h>
> +
> +static void print_help(void)
> +{
> +       printf("Usage: tst_getconf variable\n\n");
> +       printf("       variable: can be PAGESIZE or _NPROCESSORS_ONLN (for
> the moment)\n");
> +       printf("example: tst_getconf PAGESIZE\n");
> +}
> +
> +int main(int argc, char *argv[])
> +{
> +       int opt;
> +
> +       while ((opt = getopt(argc, argv, ":h")) != -1) {
> +               switch (opt) {
> +               case 'h':
> +                       print_help();
> +                       return 0;
> +               default:
> +                       print_help();
> +                       return 1;
> +               }
> +       }
>

​What about set argc limitation here?​

​    if (argc != 2) {
        print_help();
        return 1;
    }

​

> +
> +       if (optind >= argc) {
> +               fprintf(stderr, "ERROR: Expected variable argument\n\n");
> +               print_help();
> +               return 1;
> +       }
> +
> +       if (!strcmp(argv[optind], "_NPROCESSORS_ONLN"))
> +               printf("%ld", sysconf(_SC_NPROCESSORS_ONLN));
> +       else if (!strcmp(argv[optind],"PAGESIZE"))
> +               printf("%ld", sysconf(_SC_PAGE_SIZE));
>

​We'd better add a default check for invalid parameter here, assume that if
someone gives
a typo in use this tst_getconf, it's not easy to find the error.

# ./tst_getconf _NPROCESSORS_ONL  <--- typo here
# echo $?
0



> +
> +       return 0;
> +}
> --
> 2.11.0
>
>
> --
> Mailing list info: https://lists.linux.it/listinfo/ltp
>



-- 
Regards,
Li Wang
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[LTP] [PATCH 2/2] testcases: Replace "getconf" by "tst_getconf"

[Li Wang]

Mylène Josserand <mylene.josserand@bootlin.com> wrote:

> Now that tst_getconf is available to use "sysconf()" function
> instead of relying on the application "getconf", let's convert
> all the tests to it.
>
> Signed-off-by: Mylène Josserand <mylene.josserand@bootlin.com>
> ---
>  testcases/commands/du/du01.sh                                    | 2 +-
>  testcases/commands/mkswap/mkswap01.sh                            | 2 +-
>  testcases/kernel/controllers/cpuset/cpuset_regression_test.sh    | 2 +-
>  testcases/kernel/controllers/memcg/control/memcg_control_test.sh | 2 +-
>  testcases/kernel/controllers/memcg/functional/memcg_lib.sh       | 4 ++--
>  testcases/kernel/numa/numa01.sh                                  | 2 +-
>  testcases/lib/test.sh                                            | 4 ++--
>  7 files changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/testcases/commands/du/du01.sh b/testcases/commands/du/du01.sh
> index ed1df568f..c75068255 100755
> --- a/testcases/commands/du/du01.sh
> +++ b/testcases/commands/du/du01.sh
> @@ -73,7 +73,7 @@ du_test()
>  }
>
>  block_size=512
> -page_size=$(getconf PAGESIZE)
> +page_size=$(tst_getconf PAGESIZE)
>  if [ "$page_size" -lt 1024 ]; then
>         tst_brk TBROK "Page size < 1024"
>  fi
> diff --git a/testcases/commands/mkswap/mkswap01.sh
> b/testcases/commands/mkswap/mkswap01.sh
> index 1c01c86b2..743db4c1a 100755
> --- a/testcases/commands/mkswap/mkswap01.sh
> +++ b/testcases/commands/mkswap/mkswap01.sh
> @@ -29,7 +29,7 @@ setup()
>  {
>         UUID=`uuidgen`
>
> -       PAGE_SIZE=`
> ​​
> getconf PAGE_SIZE`
> +       PAGE_SIZE=`tst_getconf PAGE_SIZE`
>

Here should be corrected, from the patch 1/2, tst_getconf only supports
PAGESIZE.​


>
>         # Here get the size of the device and align it down to be the
>         # multiple of $PAGE_SIZE and use that as the size for testing.
> diff --git a/testcases/kernel/controllers/cpuset/cpuset_regression_test.sh
> b/testcases/kernel/controllers/cpuset/cpuset_regression_test.sh
> index 4a104a3ad..72a2a944c 100755
> --- a/testcases/kernel/controllers/cpuset/cpuset_regression_test.sh
> +++ b/testcases/kernel/controllers/cpuset/cpuset_regression_test.sh
> @@ -34,7 +34,7 @@ setup()
>                 tst_brkm TCONF "Test must be run with kernel 3.18.0 or
> newer"
>         fi
>
> -       local cpu_num=$(getconf _NPROCESSORS_ONLN)
> +       local cpu_num=$(tst_getconf _NPROCESSORS_ONLN)
>         if [ $cpu_num -lt 2 ]; then
>                 tst_brkm TCONF "We need 2 cpus at least to have test"
>         fi
> diff --git a/testcases/kernel/controllers/memcg/control/memcg_control_test.sh
> b/testcases/kernel/controllers/memcg/control/memcg_control_test.sh
> index 1d158729c..4d9f1bb5d 100644
> --- a/testcases/kernel/controllers/memcg/control/memcg_control_test.sh
> +++ b/testcases/kernel/controllers/memcg/control/memcg_control_test.sh
> @@ -41,7 +41,7 @@ export TST_COUNT=0
>  export TMP=${TMP:-/tmp}
>  cd $TMP
>
> -PAGE_SIZE=$(getconf PAGESIZE)
> +PAGE_SIZE=$(tst_getconf PAGESIZE)
>
>  TOT_MEM_LIMIT=$PAGE_SIZE
>  ACTIVE_MEM_LIMIT=$PAGE_SIZE
> diff --git a/testcases/kernel/controllers/memcg/functional/memcg_lib.sh
> b/testcases/kernel/controllers/memcg/functional/memcg_lib.sh
> index 6a6af853b..cd16dc685 100755
> --- a/testcases/kernel/controllers/memcg/functional/memcg_lib.sh
> +++ b/testcases/kernel/controllers/memcg/functional/memcg_lib.sh
> @@ -29,9 +29,9 @@ if [ "x$(grep -w memory /proc/cgroups | cut -f4)" !=
> "x1" ]; then
>         tst_brkm TCONF "Kernel does not support the memory resource
> controller"
>  fi
>
> -PAGESIZE=$(getconf PAGESIZE)
> +PAGESIZE=$(tst_getconf PAGESIZE)
>  if [ $? -ne 0 ]; then
> -       tst_brkm TBROK "getconf PAGESIZE failed"
> +       tst_brkm TBROK "tst_getconf PAGESIZE failed"
>  fi
>
>  HUGEPAGESIZE=$(awk '/Hugepagesize/ {print $2}' /proc/meminfo)
> diff --git a/testcases/kernel/numa/numa01.sh b/testcases/kernel/numa/
> numa01.sh
> index 27a2f2f7c..65e9b7dd5 100755
> --- a/testcases/kernel/numa/numa01.sh
> +++ b/testcases/kernel/numa/numa01.sh
> @@ -83,7 +83,7 @@ wait_for_support_numa()
>  setup()
>  {
>         export MB=$((1024*1024))
> -       export PAGE_SIZE=$(getconf PAGE_SIZE)
> +       export PAGE_SIZE=$(tst_getconf PAGE_SIZE)
>

​Here as well.
​

>         export HPAGE_SIZE=$(awk '/Hugepagesize:/ {print $2}' /proc/meminfo)
>
>         total_nodes=0
> diff --git a/testcases/lib/test.sh b/testcases/lib/test.sh
> index bce9893a9..650712181 100644
> --- a/testcases/lib/test.sh
> +++ b/testcases/lib/test.sh
> @@ -421,9 +421,9 @@ fi
>  if [ "$TST_NEEDS_CHECKPOINTS" = "1" ]; then
>         LTP_IPC_PATH="/dev/shm/ltp_${TCID}_$$"
>
> -       LTP_IPC_SIZE=$(getconf PAGESIZE)
> +       LTP_IPC_SIZE=$(tst_getconf PAGESIZE)
>         if [ $? -ne 0 ]; then
> -               tst_brkm TBROK "getconf PAGESIZE failed"
> +               tst_brkm TBROK "tst_getconf PAGESIZE failed"
>         fi
>
>         ROD_SILENT dd if=/dev/zero of="$LTP_IPC_PATH" bs="$LTP_IPC_SIZE"
> count=1
> --
> 2.11.0
>
>
> --
> Mailing list info: https://lists.linux.it/listinfo/ltp
>



-- 
Regards,
Li Wang
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[LTP] [PATCH 1/2] testcase: lib: Create tst_getconf to replace "getconf"

[=?unknown-8bit?q?Myl=C3=A8ne?= Josserand]

Hello,

On Wed, 6 Jun 2018 12:11:25 +0800
Li Wang <liwang@redhat.com> wrote:

> Mylène Josserand <mylene.josserand@bootlin.com> wrote:
> 
> > In some system, "getconf" application may not be installed.
> > Some tests are using it to retrieve some variables such as the
> > page size (PAGESIZE).
> >
> > Create a tst_getconf binary that use sysconf() function to retrieve
> > these variables instead of relying on "getconf" application that
> > may not be available.
> > Add also this new helper in the documentation.
> >
> > Example:
> > pagesize=`tst_getconf PAGESIZE`
> >
> > Signed-off-by: Mylène Josserand <mylene.josserand@bootlin.com>
> > ​[...]
> > +
> > +#include <stdio.h>
> > +#include <unistd.h>
> > +#include <string.h>
> > +
> > +static void print_help(void)
> > +{
> > +       printf("Usage: tst_getconf variable\n\n");
> > +       printf("       variable: can be PAGESIZE or _NPROCESSORS_ONLN (for
> > the moment)\n");
> > +       printf("example: tst_getconf PAGESIZE\n");
> > +}
> > +
> > +int main(int argc, char *argv[])
> > +{
> > +       int opt;
> > +
> > +       while ((opt = getopt(argc, argv, ":h")) != -1) {
> > +               switch (opt) {
> > +               case 'h':
> > +                       print_help();
> > +                       return 0;
> > +               default:
> > +                       print_help();
> > +                       return 1;
> > +               }
> > +       }
> >  
> 
> ​What about set argc limitation here?​
> 
> ​    if (argc != 2) {
>         print_help();
>         return 1;
>     }
> 
> ​

Sure, I will add it in V2.

> 
> > +
> > +       if (optind >= argc) {
> > +               fprintf(stderr, "ERROR: Expected variable argument\n\n");
> > +               print_help();
> > +               return 1;
> > +       }
> > +
> > +       if (!strcmp(argv[optind], "_NPROCESSORS_ONLN"))
> > +               printf("%ld", sysconf(_SC_NPROCESSORS_ONLN));
> > +       else if (!strcmp(argv[optind],"PAGESIZE"))
> > +               printf("%ld", sysconf(_SC_PAGE_SIZE));
> >  
> 
> ​We'd better add a default check for invalid parameter here, assume that if
> someone gives
> a typo in use this tst_getconf, it's not easy to find the error.
> 
> # ./tst_getconf _NPROCESSORS_ONL  <--- typo here
> # echo $?
> 0
> 
> 

Exact, thank you for the review.

Best regards,

-- 
Mylène Josserand, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com