[PATCH v4 0/4] Add env vars for session and cpu-affinity

[PATCH v4 0/4] Add env vars for session and cpu-affinity

[Simon Graber]

Hello,

Revision 4 of this patchset clarifies the purpose of patch 3.

Changes since v1:
 * Usage of environment variables is documented
 * lib/copperplate/init.c: Conditionally query XENO_SESSION_NAME
 * Reformat patch 2 to adhere to code style
 * Reword commit message of patch 3
 
Simon Graber (4):
  lib/copperplate: Get session name from env var
  lib/boilerplate: Get cpu-affinity from env var
  alchemytests: Set cpu-affinity by env var
  Add documentation for env vars

 doc/asciidoc/README.INSTALL.adoc             |  7 ++--
 lib/boilerplate/setup.c                      | 39 +++++++++++++++-----
 lib/copperplate/init.c                       | 21 ++++++++---
 testsuite/smokey/alchemytests/alchemytests.c | 10 ++++-
 4 files changed, 58 insertions(+), 19 deletions(-)

-- 
2.46.0

[PATCH v4 1/4] lib/copperplate: Get session name from env var

[Simon Graber]

At present, for two Xenomai processes to share resources, they must
be started with identical --session= parameters.
This is cumbersome for extensive projects involving numerous helper
processes. This commit allows the specification of the session name
via a global environment variable, namely XENO_SESSION_NAME.
The --session= parameter overrules the environment variable.

In a later patch, the --vm argument will be passed via an env var too.

Signed-off-by: Simon Graber <simon.graber@sigma-star.at>
---
 lib/copperplate/init.c | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/lib/copperplate/init.c b/lib/copperplate/init.c
index 16fc59f7a..01969cfea 100644
--- a/lib/copperplate/init.c
+++ b/lib/copperplate/init.c
@@ -114,6 +114,7 @@ static int get_session_root(int *regflags_r)
 {
 	char *sessdir, *session;
 	struct passwd *pw;
+	char *sn_env;
 	int ret;
 
 	pw = getpwuid(geteuid());
@@ -121,12 +122,20 @@ static int get_session_root(int *regflags_r)
 		return -errno;
 
 	if (__copperplate_setup_data.session_label == NULL) {
-		ret = asprintf(&session, "anon@%d", __node_id);
-		if (ret < 0)
-			return -ENOMEM;
-		__copperplate_setup_data.session_label = session;
-		*regflags_r |= REGISTRY_ANON;
-	} else if (strchr(__copperplate_setup_data.session_label, '/')) {
+		sn_env = getenv("XENO_SESSION_NAME");
+		if (sn_env) {
+			__copperplate_setup_data.session_label = strdup(sn_env);
+			if (__copperplate_setup_data.session_label == NULL)
+				return -ENOMEM;
+		} else {
+			ret = asprintf(&session, "anon@%d", __node_id);
+			if (ret < 0)
+				return -ENOMEM;
+			__copperplate_setup_data.session_label = session;
+			*regflags_r |= REGISTRY_ANON;
+		}
+	}
+	if (strchr(__copperplate_setup_data.session_label, '/')) {
 		warning("session name may not contain slashes");
 		return -EINVAL;
 	}
-- 
2.46.0

[PATCH v4 2/4] lib/boilerplate: Get cpu-affinity from env var

[Simon Graber]

It might be helpful to specify the cpu-affinity via an env var,
XENO_CPU_AFFINITY.
This commit adds a helper function, called in __xenomai_init.
The --cpu-affinity= parameter overrules the environment variable.

Signed-off-by: Simon Graber <simon.graber@sigma-star.at>
---
 lib/boilerplate/setup.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/lib/boilerplate/setup.c b/lib/boilerplate/setup.c
index 26c8c4cf5..9573a546f 100644
--- a/lib/boilerplate/setup.c
+++ b/lib/boilerplate/setup.c
@@ -383,6 +383,18 @@ void xenomai_usage(void)
         fprintf(stderr, "--help				display help\n");
 }
 
+static int set_affinity_from_env(void)
+{
+	char *affinity_env;
+	int ret = 0;
+
+	affinity_env = getenv("XENO_CPU_AFFINITY");
+	if (affinity_env)
+		ret = collect_cpu_affinity(affinity_env);
+
+	return ret;
+}
+
 static int parse_base_options(int *argcp, char **uargv,
 			      const struct option *options,
 			      int base_opt_start)
@@ -560,6 +572,11 @@ static void __xenomai_init(int *argcp, char *const **argvp, const char *me)
 	/* Retrieve the default CPU affinity. */
 	retrieve_default_cpu_affinity();
 
+	/* Environment variables can be overruled by arguments */
+	ret = set_affinity_from_env();
+	if (ret)
+		goto fail;
+
 	/*
 	 * Parse the base options first, to bootstrap the core with
 	 * the right config values.
-- 
2.46.0

[PATCH v4 3/4] alchemytests: Set cpu-affinity by env var

[Simon Graber]

The alchemy test runner can now make use of the XENO_CPU_AFFINITY
environment variable by setting it before dispatching to the individual
test programs.

While not changing anything user-visibly, this stresses the new
interface in CI and allows in a later commit to pass the --vm argument
via an env var too, removing command line injection from this test
case.

Signed-off-by: Simon Graber <simon.graber@sigma-star.at>
---
 testsuite/smokey/alchemytests/alchemytests.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/testsuite/smokey/alchemytests/alchemytests.c b/testsuite/smokey/alchemytests/alchemytests.c
index cf9f970f1..edbafe6e7 100644
--- a/testsuite/smokey/alchemytests/alchemytests.c
+++ b/testsuite/smokey/alchemytests/alchemytests.c
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <string.h>
+#include <stdlib.h>
 #include <smokey/smokey.h>
 
 static const char * const tests[] = {
@@ -31,12 +32,19 @@ static const char * const tests[] = {
 
 static int run_alchemytests(struct smokey_test *t, int argc, char *const argv[])
 {
-	const char *args = "--vm --cpu-affinity=0";
 	const char *const mod = "xeno_rtipc";
+	const char *args = "--vm";
 	int test_ret = 0;
 	int ret = 0;
 	int tmp;
 
+	ret = setenv("XENO_CPU_AFFINITY", "0", 0);
+	if (ret != 0) {
+		fprintf(stderr, "%s failed to set XENO_CPU_AFFINITY: %m\n",
+			__func__);
+		return ret;
+	}
+
 	/* Try loading the xeno_rtipc module as the pipe test depends on it */
 	tmp = smokey_modprobe(mod, true);
 	if (tmp)
-- 
2.46.0

[PATCH v4 4/4] Add documentation for env vars

[Simon Graber]

Usage message in lib/boilerplate/setup.c now prints
XENO_CPU_AFFINITY and XENO_SESSION_NAME.

The usage of the session arg/env var are also
described in README.INSTALL.adoc.

Signed-off-by: Simon Graber <simon.graber@sigma-star.at>
---
 doc/asciidoc/README.INSTALL.adoc |  7 ++++---
 lib/boilerplate/setup.c          | 22 +++++++++++++---------
 2 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/doc/asciidoc/README.INSTALL.adoc b/doc/asciidoc/README.INSTALL.adoc
index d2b7e6f78..52bef566d 100644
--- a/doc/asciidoc/README.INSTALL.adoc
+++ b/doc/asciidoc/README.INSTALL.adoc
@@ -428,9 +428,10 @@ Generic configuration options (both cores)
 When this option is enabled, the system creates a file hierachy at
 `<user>/<session>/<pid>` under the registry root path, where you
 can access the internal state of the active real-time objects. The
-session label is obtained from the --session runtime switch. If no
-session name is specified, `anon@<pid>` will be used. E.g. looking at
-the properties of a VxWorks task could be done as follows:
+session label is obtained from the `--session` runtime switch, which
+takes precedence over the environment variable `XENO_SESSION_NAME`.
+If neither of these are specified, `anon@<pid>` will be used. E.g.
+looking at the properties of a VxWorks task could be done as follows:
 
 If not specified in the configuration switch, the registry root path
 will be +/var/run/xenomai+.
diff --git a/lib/boilerplate/setup.c b/lib/boilerplate/setup.c
index 9573a546f..7bb24f6f4 100644
--- a/lib/boilerplate/setup.c
+++ b/lib/boilerplate/setup.c
@@ -370,17 +370,21 @@ void xenomai_usage(void)
 		}
 	}
 
-        fprintf(stderr, "--cpu-affinity=<cpu[,cpu]...>	set CPU affinity of threads\n");
-        fprintf(stderr, "--[no-]sanity			disable/enable sanity checks\n");
-        fprintf(stderr, "--verbose[=level] 		set verbosity to desired level [=1]\n");
-        fprintf(stderr, "--silent, --quiet 		same as --verbose=0\n");
-        fprintf(stderr, "--trace[=level] 		set tracing to desired level [=1]\n");
-        fprintf(stderr, "--version			get version information\n");
-        fprintf(stderr, "--dump-config			dump configuration settings\n");
+	fprintf(stderr, "--session=<label>[/<group>]	enable shared session\n");
+	fprintf(stderr, "--cpu-affinity=<cpu[,cpu]...>	set CPU affinity of threads\n");
+	fprintf(stderr, "--[no-]sanity			disable/enable sanity checks\n");
+	fprintf(stderr, "--verbose[=level]		set verbosity to desired level [=1]\n");
+	fprintf(stderr, "--silent, --quiet		same as --verbose=0\n");
+	fprintf(stderr, "--trace[=level]		set tracing to desired level [=1]\n");
+	fprintf(stderr, "--version			get version information\n");
+	fprintf(stderr, "--dump-config			dump configuration settings\n");
 #ifdef CONFIG_XENO_MERCURY
-        fprintf(stderr, "--no-mlock			do not lock memory at init\n");
+	fprintf(stderr, "--no-mlock			do not lock memory at init\n");
 #endif
-        fprintf(stderr, "--help				display help\n");
+	fprintf(stderr, "--help				display help\n");
+	fprintf(stderr, "\nEnvironment variables (arguments take priority):\n"
+			"XENO_SESSION_NAME=<label>[/<group>]	enable shared session\n"
+			"XENO_CPU_AFFINITY=<cpu[,cpu]...>	set CPU affinity of threads\n");
 }
 
 static int set_affinity_from_env(void)
-- 
2.46.0

Re: [PATCH v4 0/4] Add env vars for session and cpu-affinity

[Jan Kiszka]

On 02.09.24 15:11, Simon Graber wrote:
> Hello,
> 
> Revision 4 of this patchset clarifies the purpose of patch 3.
> 
> Changes since v1:
>  * Usage of environment variables is documented
>  * lib/copperplate/init.c: Conditionally query XENO_SESSION_NAME
>  * Reformat patch 2 to adhere to code style
>  * Reword commit message of patch 3
>  
> Simon Graber (4):
>   lib/copperplate: Get session name from env var
>   lib/boilerplate: Get cpu-affinity from env var
>   alchemytests: Set cpu-affinity by env var
>   Add documentation for env vars
> 
>  doc/asciidoc/README.INSTALL.adoc             |  7 ++--
>  lib/boilerplate/setup.c                      | 39 +++++++++++++++-----
>  lib/copperplate/init.c                       | 21 ++++++++---
>  testsuite/smokey/alchemytests/alchemytests.c | 10 ++++-
>  4 files changed, 58 insertions(+), 19 deletions(-)
> 

Thanks, applied.

Jan

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Siemens AG, Technology
Linux Expert Center

Re: [PATCH v4 3/4] alchemytests: Set cpu-affinity by env var

[Jan Kiszka]

On 02.09.24 15:11, Simon Graber wrote:
> The alchemy test runner can now make use of the XENO_CPU_AFFINITY
> environment variable by setting it before dispatching to the individual
> test programs.
> 
> While not changing anything user-visibly, this stresses the new
> interface in CI and allows in a later commit to pass the --vm argument
> via an env var too, removing command line injection from this test
> case.
> 
> Signed-off-by: Simon Graber <simon.graber@sigma-star.at>
> ---
>  testsuite/smokey/alchemytests/alchemytests.c | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/testsuite/smokey/alchemytests/alchemytests.c b/testsuite/smokey/alchemytests/alchemytests.c
> index cf9f970f1..edbafe6e7 100644
> --- a/testsuite/smokey/alchemytests/alchemytests.c
> +++ b/testsuite/smokey/alchemytests/alchemytests.c
> @@ -1,5 +1,6 @@
>  // SPDX-License-Identifier: GPL-2.0
>  #include <string.h>
> +#include <stdlib.h>
>  #include <smokey/smokey.h>
>  
>  static const char * const tests[] = {
> @@ -31,12 +32,19 @@ static const char * const tests[] = {
>  
>  static int run_alchemytests(struct smokey_test *t, int argc, char *const argv[])
>  {
> -	const char *args = "--vm --cpu-affinity=0";
>  	const char *const mod = "xeno_rtipc";
> +	const char *args = "--vm";
>  	int test_ret = 0;
>  	int ret = 0;
>  	int tmp;
>  
> +	ret = setenv("XENO_CPU_AFFINITY", "0", 0);
> +	if (ret != 0) {
> +		fprintf(stderr, "%s failed to set XENO_CPU_AFFINITY: %m\n",
> +			__func__);
> +		return ret;
> +	}
> +
>  	/* Try loading the xeno_rtipc module as the pipe test depends on it */
>  	tmp = smokey_modprobe(mod, true);
>  	if (tmp)

I suspect we have some regression here as I see a lot of heap-1 tests
failing in qemu runners, see eg.

https://source.denx.de/Xenomai/xenomai-images/-/jobs/918773
https://source.denx.de/Xenomai/xenomai-images/-/jobs/918984

Could you check this?

Jan

-- 
Siemens AG, Technology
Linux Expert Center

Re: [PATCH v4 3/4] alchemytests: Set cpu-affinity by env var

[Richard Weinberger]

Am Dienstag, 15. Oktober 2024, 12:02:01 CEST schrieb 'Jan Kiszka' via upstream:
> I suspect we have some regression here as I see a lot of heap-1 tests
> failing in qemu runners, see eg.
> 
> https://source.denx.de/Xenomai/xenomai-images/-/jobs/918773
> https://source.denx.de/Xenomai/xenomai-images/-/jobs/918984
> 
> Could you check this?

I'll. Simon was our intern this summer. :-)

Thanks,
//richard

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Re: [PATCH v4 3/4] alchemytests: Set cpu-affinity by env var

[Jan Kiszka]

On 15.10.24 12:04, Richard Weinberger wrote:
> Am Dienstag, 15. Oktober 2024, 12:02:01 CEST schrieb 'Jan Kiszka' via upstream:
>> I suspect we have some regression here as I see a lot of heap-1 tests
>> failing in qemu runners, see eg.
>>
>> https://source.denx.de/Xenomai/xenomai-images/-/jobs/918773
>> https://source.denx.de/Xenomai/xenomai-images/-/jobs/918984
>>
>> Could you check this?
> 
> I'll. Simon was our intern this summer. :-)
> 

Looks more like another on-vm issue: We are only waiting 1 ms in
foreground_task for the background_task to run into its final
rt_heap_alloc. If the host is busy, that may not be enough.

Jan

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Linux Expert Center