validate_resctrl_feature_request() is used to test both if a resource is
present in the info directory, and if a passed monitoring feature is
present in the mon_features file.

Refactor validate_resctrl_feature_request() into two smaller functions
that each accomplish one check to give feature checking more
granularity:
- Resource directory presence in the /sys/fs/resctrl/info directory.
- Feature name presence in the /sys/fs/resctrl/info/<RESOURCE>/mon_features
  file.

Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>
---
Changelog v5:
- Move back to using resource parameter in mon_feature handling
  function. (Ilpo)

Changelog v4:
- Roll back to using test_resource_feature_check() for CMT and MBA.
  (Ilpo).

Changelog v3:
- Move new function to a separate patch. (Reinette)
- Rewrite resctrl_mon_feature_exists() only for L3_MON.

Changelog v2:
- Add this patch.

 tools/testing/selftests/resctrl/cmt_test.c  |  2 +-
 tools/testing/selftests/resctrl/mba_test.c  |  2 +-
 tools/testing/selftests/resctrl/mbm_test.c  |  6 ++--
 tools/testing/selftests/resctrl/resctrl.h   |  4 ++-
 tools/testing/selftests/resctrl/resctrlfs.c | 33 ++++++++++++++-------
 5 files changed, 31 insertions(+), 16 deletions(-)

diff --git a/tools/testing/selftests/resctrl/cmt_test.c b/tools/testing/selftests/resctrl/cmt_test.c
index dd5ca343c469..a81f91222a89 100644
--- a/tools/testing/selftests/resctrl/cmt_test.c
+++ b/tools/testing/selftests/resctrl/cmt_test.c
@@ -170,7 +170,7 @@ static int cmt_run_test(const struct resctrl_test *test, const struct user_param
 static bool cmt_feature_check(const struct resctrl_test *test)
 {
 	return test_resource_feature_check(test) &&
-	       validate_resctrl_feature_request("L3_MON", "llc_occupancy");
+	       resctrl_mon_feature_exists("L3_MON", "llc_occupancy");
 }
 
 struct resctrl_test cmt_test = {
diff --git a/tools/testing/selftests/resctrl/mba_test.c b/tools/testing/selftests/resctrl/mba_test.c
index da256d2dbe5c..7946e32e85c8 100644
--- a/tools/testing/selftests/resctrl/mba_test.c
+++ b/tools/testing/selftests/resctrl/mba_test.c
@@ -171,7 +171,7 @@ static int mba_run_test(const struct resctrl_test *test, const struct user_param
 static bool mba_feature_check(const struct resctrl_test *test)
 {
 	return test_resource_feature_check(test) &&
-	       validate_resctrl_feature_request("L3_MON", "mbm_local_bytes");
+	       resctrl_mon_feature_exists("L3_MON", "mbm_local_bytes");
 }
 
 struct resctrl_test mba_test = {
diff --git a/tools/testing/selftests/resctrl/mbm_test.c b/tools/testing/selftests/resctrl/mbm_test.c
index 34879e7b71a0..d67ffa3ec63a 100644
--- a/tools/testing/selftests/resctrl/mbm_test.c
+++ b/tools/testing/selftests/resctrl/mbm_test.c
@@ -97,7 +97,7 @@ static int mbm_setup(const struct resctrl_test *test,
 		return END_OF_TESTS;
 
 	/* Set up shemata with 100% allocation on the first run. */
-	if (p->num_of_runs == 0 && validate_resctrl_feature_request("MB", NULL))
+	if (p->num_of_runs == 0 && resctrl_resource_exists("MB"))
 		ret = write_schemata(p->ctrlgrp, "100", uparams->cpu, test->resource);
 
 	p->num_of_runs++;
@@ -140,8 +140,8 @@ static int mbm_run_test(const struct resctrl_test *test, const struct user_param
 
 static bool mbm_feature_check(const struct resctrl_test *test)
 {
-	return validate_resctrl_feature_request("L3_MON", "mbm_total_bytes") &&
-	       validate_resctrl_feature_request("L3_MON", "mbm_local_bytes");
+	return resctrl_mon_feature_exists("L3_MON", "mbm_total_bytes") &&
+	       resctrl_mon_feature_exists("L3_MON", "mbm_local_bytes");
 }
 
 struct resctrl_test mbm_test = {
diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
index 5116ea082d03..f434a6543b4f 100644
--- a/tools/testing/selftests/resctrl/resctrl.h
+++ b/tools/testing/selftests/resctrl/resctrl.h
@@ -136,7 +136,9 @@ int get_domain_id(const char *resource, int cpu_no, int *domain_id);
 int mount_resctrlfs(void);
 int umount_resctrlfs(void);
 int validate_bw_report_request(char *bw_report);
-bool validate_resctrl_feature_request(const char *resource, const char *feature);
+bool resctrl_resource_exists(const char *resource);
+bool resctrl_mon_feature_exists(const char *resource, const char *feature);
+bool resource_info_file_exists(const char *resource, const char *file);
 bool test_resource_feature_check(const struct resctrl_test *test);
 char *fgrep(FILE *inf, const char *str);
 int taskset_benchmark(pid_t bm_pid, int cpu_no, cpu_set_t *old_affinity);
diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
index 8a183c73bc23..af4f800ab23d 100644
--- a/tools/testing/selftests/resctrl/resctrlfs.c
+++ b/tools/testing/selftests/resctrl/resctrlfs.c
@@ -708,20 +708,16 @@ char *fgrep(FILE *inf, const char *str)
 }
 
 /*
- * validate_resctrl_feature_request - Check if requested feature is valid.
- * @resource:	Required resource (e.g., MB, L3, L2, L3_MON, etc.)
- * @feature:	Required monitor feature (in mon_features file). Can only be
- *		set for L3_MON. Must be NULL for all other resources.
+ * resctrl_resource_exists - Check if a resource is supported.
+ * @resource:	Resctrl resource (e.g., MB, L3, L2, L3_MON, etc.)
  *
- * Return: True if the resource/feature is supported, else false. False is
+ * Return: True if the resource is supported, else false. False is
  *         also returned if resctrl FS is not mounted.
  */
-bool validate_resctrl_feature_request(const char *resource, const char *feature)
+bool resctrl_resource_exists(const char *resource)
 {
 	char res_path[PATH_MAX];
 	struct stat statbuf;
-	char *res;
-	FILE *inf;
 	int ret;
 
 	if (!resource)
@@ -736,8 +732,25 @@ bool validate_resctrl_feature_request(const char *resource, const char *feature)
 	if (stat(res_path, &statbuf))
 		return false;
 
+	return true;
+}
+
+/*
+ * resctrl_mon_feature_exists - Check if requested monitoring feature is valid.
+ * @resource:	Resource that uses the mon_features file. Currently only L3_MON
+ *		is valid.
+ * @feature:	Required monitor feature (in mon_features file).
+ *
+ * Return: True if the feature is supported, else false.
+ */
+bool resctrl_mon_feature_exists(const char *resource, const char *feature)
+{
+	char res_path[PATH_MAX];
+	char *res;
+	FILE *inf;
+
 	if (!feature)
-		return true;
+		return false;
 
 	snprintf(res_path, sizeof(res_path), "%s/%s/mon_features", INFO_PATH, resource);
 	inf = fopen(res_path, "r");
@@ -753,7 +766,7 @@ bool validate_resctrl_feature_request(const char *resource, const char *feature)
 
 bool test_resource_feature_check(const struct resctrl_test *test)
 {
-	return validate_resctrl_feature_request(test->resource, NULL);
+	return resctrl_resource_exists(test->resource);
 }
 
 int filter_dmesg(void)
-- 
2.43.0

Hi Maciej,

On 2/9/2024 6:01 AM, Maciej Wieczor-Retman wrote:

...

> diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
> index 5116ea082d03..f434a6543b4f 100644
> --- a/tools/testing/selftests/resctrl/resctrl.h
> +++ b/tools/testing/selftests/resctrl/resctrl.h
> @@ -136,7 +136,9 @@ int get_domain_id(const char *resource, int cpu_no, int *domain_id);
>  int mount_resctrlfs(void);
>  int umount_resctrlfs(void);
>  int validate_bw_report_request(char *bw_report);
> -bool validate_resctrl_feature_request(const char *resource, const char *feature);
> +bool resctrl_resource_exists(const char *resource);
> +bool resctrl_mon_feature_exists(const char *resource, const char *feature);
> +bool resource_info_file_exists(const char *resource, const char *file);

Portion of next patch sneaked in here.

>  bool test_resource_feature_check(const struct resctrl_test *test);
>  char *fgrep(FILE *inf, const char *str);
>  int taskset_benchmark(pid_t bm_pid, int cpu_no, cpu_set_t *old_affinity);
> diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
> index 8a183c73bc23..af4f800ab23d 100644
> --- a/tools/testing/selftests/resctrl/resctrlfs.c
> +++ b/tools/testing/selftests/resctrl/resctrlfs.c
> @@ -708,20 +708,16 @@ char *fgrep(FILE *inf, const char *str)
>  }
>  
>  /*
> - * validate_resctrl_feature_request - Check if requested feature is valid.
> - * @resource:	Required resource (e.g., MB, L3, L2, L3_MON, etc.)
> - * @feature:	Required monitor feature (in mon_features file). Can only be
> - *		set for L3_MON. Must be NULL for all other resources.
> + * resctrl_resource_exists - Check if a resource is supported.
> + * @resource:	Resctrl resource (e.g., MB, L3, L2, L3_MON, etc.)
>   *
> - * Return: True if the resource/feature is supported, else false. False is
> + * Return: True if the resource is supported, else false. False is
>   *         also returned if resctrl FS is not mounted.
>   */
> -bool validate_resctrl_feature_request(const char *resource, const char *feature)
> +bool resctrl_resource_exists(const char *resource)
>  {
>  	char res_path[PATH_MAX];
>  	struct stat statbuf;
> -	char *res;
> -	FILE *inf;
>  	int ret;
>  
>  	if (!resource)
> @@ -736,8 +732,25 @@ bool validate_resctrl_feature_request(const char *resource, const char *feature)
>  	if (stat(res_path, &statbuf))
>  		return false;
>  
> +	return true;
> +}
> +
> +/*
> + * resctrl_mon_feature_exists - Check if requested monitoring feature is valid.
> + * @resource:	Resource that uses the mon_features file. Currently only L3_MON
> + *		is valid.
> + * @feature:	Required monitor feature (in mon_features file).
> + *
> + * Return: True if the feature is supported, else false.
> + */
> +bool resctrl_mon_feature_exists(const char *resource, const char *feature)
> +{
> +	char res_path[PATH_MAX];
> +	char *res;
> +	FILE *inf;
> +
>  	if (!feature)

Now that resource is a new parameter should it be checked also? It is not obvious
why only one parameter is checked.

Reinette

Hi,

On 2024-02-09 at 09:20:27 -0800, Reinette Chatre wrote:
>Hi Maciej,
>
>On 2/9/2024 6:01 AM, Maciej Wieczor-Retman wrote:
>
>...
>
>> diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
>> index 5116ea082d03..f434a6543b4f 100644
>> --- a/tools/testing/selftests/resctrl/resctrl.h
>> +++ b/tools/testing/selftests/resctrl/resctrl.h
>> @@ -136,7 +136,9 @@ int get_domain_id(const char *resource, int cpu_no, int *domain_id);
>>  int mount_resctrlfs(void);
>>  int umount_resctrlfs(void);
>>  int validate_bw_report_request(char *bw_report);
>> -bool validate_resctrl_feature_request(const char *resource, const char *feature);
>> +bool resctrl_resource_exists(const char *resource);
>> +bool resctrl_mon_feature_exists(const char *resource, const char *feature);
>> +bool resource_info_file_exists(const char *resource, const char *file);
>
>Portion of next patch sneaked in here.

Missed it, thanks for pointing that out!

>
>>  bool test_resource_feature_check(const struct resctrl_test *test);
>>  char *fgrep(FILE *inf, const char *str);
>>  int taskset_benchmark(pid_t bm_pid, int cpu_no, cpu_set_t *old_affinity);
>> diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
>> index 8a183c73bc23..af4f800ab23d 100644
>> --- a/tools/testing/selftests/resctrl/resctrlfs.c
>> +++ b/tools/testing/selftests/resctrl/resctrlfs.c
>> @@ -708,20 +708,16 @@ char *fgrep(FILE *inf, const char *str)
>>  }
>>  
>>  /*
>> - * validate_resctrl_feature_request - Check if requested feature is valid.
>> - * @resource:	Required resource (e.g., MB, L3, L2, L3_MON, etc.)
>> - * @feature:	Required monitor feature (in mon_features file). Can only be
>> - *		set for L3_MON. Must be NULL for all other resources.
>> + * resctrl_resource_exists - Check if a resource is supported.
>> + * @resource:	Resctrl resource (e.g., MB, L3, L2, L3_MON, etc.)
>>   *
>> - * Return: True if the resource/feature is supported, else false. False is
>> + * Return: True if the resource is supported, else false. False is
>>   *         also returned if resctrl FS is not mounted.
>>   */
>> -bool validate_resctrl_feature_request(const char *resource, const char *feature)
>> +bool resctrl_resource_exists(const char *resource)
>>  {
>>  	char res_path[PATH_MAX];
>>  	struct stat statbuf;
>> -	char *res;
>> -	FILE *inf;
>>  	int ret;
>>  
>>  	if (!resource)
>> @@ -736,8 +732,25 @@ bool validate_resctrl_feature_request(const char *resource, const char *feature)
>>  	if (stat(res_path, &statbuf))
>>  		return false;
>>  
>> +	return true;
>> +}
>> +
>> +/*
>> + * resctrl_mon_feature_exists - Check if requested monitoring feature is valid.
>> + * @resource:	Resource that uses the mon_features file. Currently only L3_MON
>> + *		is valid.
>> + * @feature:	Required monitor feature (in mon_features file).
>> + *
>> + * Return: True if the feature is supported, else false.
>> + */
>> +bool resctrl_mon_feature_exists(const char *resource, const char *feature)
>> +{
>> +	char res_path[PATH_MAX];
>> +	char *res;
>> +	FILE *inf;
>> +
>>  	if (!feature)
>
>Now that resource is a new parameter should it be checked also? It is not obvious
>why only one parameter is checked.

Right, I'll add the check there.

>
>Reinette

-- 
Kind regards
Maciej Wieczór-Retman