[LTP] [PATCH v4 1/3] lib: add tst_get_free_pids helper program

[LTP] [PATCH v4 1/3] lib: add tst_get_free_pids helper program

[Krzysztof Kozlowski]

Add a tst_get_free_pids helper program so shell code can get limit of
tasks/PIDs in the system without duplicating that code.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
---
 testcases/lib/.gitignore          |  1 +
 testcases/lib/Makefile            |  2 +-
 testcases/lib/tst_get_free_pids.c | 19 +++++++++++++++++++
 3 files changed, 21 insertions(+), 1 deletion(-)
 create mode 100644 testcases/lib/tst_get_free_pids.c

diff --git a/testcases/lib/.gitignore b/testcases/lib/.gitignore
index a2e9f1ef0c08..5a0e8cba2ee7 100644
--- a/testcases/lib/.gitignore
+++ b/testcases/lib/.gitignore
@@ -2,6 +2,7 @@
 /tst_checkpoint
 /tst_device
 /tst_getconf
+/tst_get_free_pids
 /tst_get_median
 /tst_get_unused_port
 /tst_kvcmp
diff --git a/testcases/lib/Makefile b/testcases/lib/Makefile
index 38813e640ab1..179b474795d3 100644
--- a/testcases/lib/Makefile
+++ b/testcases/lib/Makefile
@@ -11,6 +11,6 @@ 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_getconf tst_supported_fs tst_check_drivers tst_get_unused_port\
-			   tst_get_median tst_hexdump
+			   tst_get_median tst_hexdump tst_get_free_pids
 
 include $(top_srcdir)/include/mk/generic_leaf_target.mk
diff --git a/testcases/lib/tst_get_free_pids.c b/testcases/lib/tst_get_free_pids.c
new file mode 100644
index 000000000000..276ce994b67a
--- /dev/null
+++ b/testcases/lib/tst_get_free_pids.c
@@ -0,0 +1,19 @@
+
+#define TST_NO_DEFAULT_MAIN
+#include <stdio.h>
+#include <tst_test.h>
+
+extern struct tst_test *tst_test;
+
+static struct tst_test test = {
+};
+
+int main(void)
+{
+	/* force messages to be printed from new library */
+	tst_test = &test;
+
+	printf("%i\n", tst_get_free_pids());
+
+	return 0;
+}
-- 
2.30.2

[LTP] [PATCH v4 2/3] controllers/cpuacct: skip cpuacct_100_100 on small memory systems

[Krzysztof Kozlowski]

Running cpuacct_100_100 on a system with less than ~4 GB of RAM fails:

    cpuacct 1 TINFO: timeout per run is 0h 5m 0s
    cpuacct 1 TINFO: cpuacct: /sys/fs/cgroup/cpu,cpuacct
    cpuacct 1 TINFO: Creating 100 subgroups each with 100 processes
    testcases/bin/cpuacct.sh: 0: Cannot fork

In dmesg:

    LTP: starting cpuacct_100_100 (cpuacct.sh 100 100)
    cgroup: fork rejected by pids controller in /user.slice/user-1000.slice/session-1.scope

The reason is cgroups pid limit set by systemd user.slice.  For example
on 2 GB RAM machine it is set as:
    /sys/fs/cgroup/pids/user.slice/user-0.slice/pids.max:5207

Add a check for both free memory and maximum number of pids (when using
systemd) to skip the test.  Systems not using systemd might still fail.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>

---

Changes since v3:
1. Use tst_get_free_pids helper.

Changes since v2:
1. Correct realuid->real_uid typo.
2. Correct handling dash shell tests for return value.
3. Correct handling numbers - infinite.

Changes since v1:
1. Add checking for pids.
2. Accurately check the memory constraints.
---
 .../kernel/controllers/cpuacct/cpuacct.sh     | 49 +++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/testcases/kernel/controllers/cpuacct/cpuacct.sh b/testcases/kernel/controllers/cpuacct/cpuacct.sh
index 323aa7513bf4..39f880a53996 100755
--- a/testcases/kernel/controllers/cpuacct/cpuacct.sh
+++ b/testcases/kernel/controllers/cpuacct/cpuacct.sh
@@ -38,12 +38,61 @@ OPTIONS
 EOF
 }
 
+check_free_memory()
+{
+	local memneeded
+	local memfree=`awk '/MemAvailable/ {print $2}' /proc/meminfo`
+
+	if [ $? -ne 0 ]; then
+		local memcached
+
+		memfree=`awk '/MemFree/ {print $2}' /proc/meminfo`
+		test $? -eq 0 || return 0
+
+		memcached=`awk '/MemCached/ {print $2}' /proc/meminfo`
+		test $? -eq 0 || return 0
+
+		memfree=$((memfree + memcached))
+	fi
+
+	# On x86_64, each 100 of processes were using ~16 MB of memory,
+	# so try to estimate the needed free memory based on this.
+	memneeded=$((max * nbprocess * 16384 / 100))
+
+	if [ $memfree -lt $memneeded ]; then
+		tst_brk TCONF "not enough of free memory on this system (approximate need $memneeded kB, free $memfree kB)"
+	fi
+	tst_res TINFO "memory requirements fulfilled (approximate need $memneeded kB, free $memfree kB)"
+
+	return 0
+}
+
+check_limits()
+{
+	local tasksneeded=$((max * nbprocess + 100))
+	local tasksmax=$(tst_get_free_pids)
+	test $? -eq 0 || return 0
+
+	if [ $tasksmax -le $tasksneeded ]; then
+		tst_brk TCONF "limit of tasks is too low (approximate need $tasksneeded, limit $tasksmax)"
+	fi
+	tst_res TINFO "task limit fulfilled (approximate need $tasksneeded, limit $tasksmax)"
+
+	return 0
+}
+
 setup()
 {
 	if ! grep -q -w cpuacct /proc/cgroups; then
 		tst_brk TCONF "cpuacct not supported on this system"
 	fi
 
+	check_limits
+	# Don't bother with memory limit checks on smaller tests
+	if [ $max -ge 100 ] && [ $nbprocess -ge 100 ]; then
+		check_free_memory
+	fi
+
 	mount_point=`grep -w cpuacct /proc/mounts | cut -f 2 | cut -d " " -f2`
 	tst_res TINFO "cpuacct: $mount_point"
 	if [ "$mount_point" = "" ]; then
-- 
2.30.2

[LTP] [PATCH v4 3/3] controllers/cpuacct: fix rmdir failures on early test abort

[Krzysztof Kozlowski]

The "testpath" variable is assigned at the end of setup(), so if test
exits early, the "rmdir $testpath" is wrong:

    cpuacct 1 TCONF: not enough of memory on this system (less than 3840 MB)
    cpuacct 1 TINFO: removing created directories
    rmdir: missing operand
    Try 'rmdir --help' for more information.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>

---

Changes since v1:
1. None.
---
 testcases/kernel/controllers/cpuacct/cpuacct.sh | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/testcases/kernel/controllers/cpuacct/cpuacct.sh b/testcases/kernel/controllers/cpuacct/cpuacct.sh
index 39f880a53996..e95d4b53f936 100755
--- a/testcases/kernel/controllers/cpuacct/cpuacct.sh
+++ b/testcases/kernel/controllers/cpuacct/cpuacct.sh
@@ -120,12 +120,13 @@ cleanup()
 {
 	tst_res TINFO "removing created directories"
 
-	if [ -d "$testpath/subgroup_1" ]; then
-		rmdir $testpath/subgroup_*
+	if [ "$testpath" ]; then
+		if [ -d "$testpath/subgroup_1" ]; then
+			rmdir $testpath/subgroup_*
+		fi
+		rmdir $testpath
 	fi
 
-	rmdir $testpath
-
 	if [ "$mounted" -ne 1 ]; then
 		tst_res TINFO "Umounting cpuacct"
 		umount $mount_point
-- 
2.30.2

[LTP] [PATCH v4 1/3] lib: add tst_get_free_pids helper program

[Krzysztof Kozlowski]

On 01/09/2021 16:51, Krzysztof Kozlowski wrote:
> Add a tst_get_free_pids helper program so shell code can get limit of
> tasks/PIDs in the system without duplicating that code.
> 
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
> ---
>  testcases/lib/.gitignore          |  1 +
>  testcases/lib/Makefile            |  2 +-
>  testcases/lib/tst_get_free_pids.c | 19 +++++++++++++++++++
>  3 files changed, 21 insertions(+), 1 deletion(-)
>  create mode 100644 testcases/lib/tst_get_free_pids.c
> 
> diff --git a/testcases/lib/.gitignore b/testcases/lib/.gitignore
> index a2e9f1ef0c08..5a0e8cba2ee7 100644
> --- a/testcases/lib/.gitignore
> +++ b/testcases/lib/.gitignore
> @@ -2,6 +2,7 @@
>  /tst_checkpoint
>  /tst_device
>  /tst_getconf
> +/tst_get_free_pids
>  /tst_get_median
>  /tst_get_unused_port
>  /tst_kvcmp
> diff --git a/testcases/lib/Makefile b/testcases/lib/Makefile
> index 38813e640ab1..179b474795d3 100644
> --- a/testcases/lib/Makefile
> +++ b/testcases/lib/Makefile
> @@ -11,6 +11,6 @@ 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_getconf tst_supported_fs tst_check_drivers tst_get_unused_port\
> -			   tst_get_median tst_hexdump
> +			   tst_get_median tst_hexdump tst_get_free_pids
>  
>  include $(top_srcdir)/include/mk/generic_leaf_target.mk
> diff --git a/testcases/lib/tst_get_free_pids.c b/testcases/lib/tst_get_free_pids.c
> new file mode 100644
> index 000000000000..276ce994b67a
> --- /dev/null
> +++ b/testcases/lib/tst_get_free_pids.c
> @@ -0,0 +1,19 @@
> +

It's missing SPDX. I'll send a v5.


Best regards,
Krzysztof