Re: [PATCH v2 3/4] selftests/resctrl: Split validate_resctrl_feature_request()

Hi Maciej,

On 12/12/2023 6:52 AM, Maciej Wieczor-Retman wrote:

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. There exists a different way to represent feature support and that is by the presence of 0 or 1 in single file in the info/resource directory. In this case the filename represents what feature support is being indicated.

Split validate_resctrl_feature_request() into three smaller functions that each accomplish one check:

• Resource directory presence in the /sys/fs/resctrl/info directory.
• Feature name presence in the /sys/fs/resctrl/info/RESOURCE/mon_features file.
• Feature file presence in a given /sys/fs/resctrl/info/RESOURCE directory.

Please present refactoring of existing code and introduction of new feature as separate patches.

Signed-off-by: Maciej Wieczor-Retman maciej.wieczor-retman@intel.com

Changelog v2:

• Added this patch.

tools/testing/selftests/resctrl/cat_test.c | 2 - tools/testing/selftests/resctrl/cmt_test.c | 4 +- tools/testing/selftests/resctrl/mba_test.c | 5 +- tools/testing/selftests/resctrl/mbm_test.c | 6 +-- tools/testing/selftests/resctrl/resctrl.h | 6 ++- tools/testing/selftests/resctrl/resctrlfs.c | 59 +++++++++++++++++---- 6 files changed, 63 insertions(+), 19 deletions(-)

diff --git a/tools/testing/selftests/resctrl/cat_test.c b/tools/testing/selftests/resctrl/cat_test.c index 39fc9303b8e8..7dc7206b3b99 100644 --- a/tools/testing/selftests/resctrl/cat_test.c +++ b/tools/testing/selftests/resctrl/cat_test.c @@ -1,9 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 /*

• Cache Allocation Technology (CAT) test

• • Copyright (C) 2018 Intel Corporation
• • Authors:
  • Sai Praneeth Prakhya sai.praneeth.prakhya@intel.com,
  • Fenghua Yu fenghua.yu@intel.com

Some unrelated changes here.

diff --git a/tools/testing/selftests/resctrl/cmt_test.c b/tools/testing/selftests/resctrl/cmt_test.c index dd5ca343c469..7b63aec8e2c4 100644 --- a/tools/testing/selftests/resctrl/cmt_test.c +++ b/tools/testing/selftests/resctrl/cmt_test.c @@ -169,8 +169,8 @@ 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");
  

• return resctrl_mon_feature_exists("L3_MON", "llc_occupancy") &&

•       resctrl_resource_exists("L3");
  

} 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..ecf1c186448d 100644 --- a/tools/testing/selftests/resctrl/mba_test.c +++ b/tools/testing/selftests/resctrl/mba_test.c @@ -170,8 +170,9 @@ 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");
  

• return resctrl_resource_exists(test->resource) &&

•       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 8f72d94b9cbe..74041a35d4ba 100644 --- a/tools/testing/selftests/resctrl/resctrl.h +++ b/tools/testing/selftests/resctrl/resctrl.h @@ -135,7 +135,11 @@ 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 resctrl_cache_feature_exists(const char *resource,

• 		  const char *feature);
  

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 70333440ff2f..8546421f0940 100644 --- a/tools/testing/selftests/resctrl/resctrlfs.c +++ b/tools/testing/selftests/resctrl/resctrlfs.c @@ -697,20 +697,16 @@ 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) @@ -725,6 +721,25 @@ 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 feature is valid.
• • @resource: Required resource (e.g., MB, L3, L2, L3_MON, etc.)

If this is intended for the monitoring resource and L3_MON (per below) is the only valid resource then @resource cannot be all of the examples shown. Why is the @resource argument needed?

• • @feature: Required monitor feature (in mon_features file). Can only be

• • set for L3_MON. Must be NULL for all other resources.
    

Which other resources?

• • Return: True if the resource/feature is supported, else false. False is

• •     also returned if resctrl FS is not mounted.
    

• */

+bool resctrl_mon_feature_exists(const char *resource,

• 		const char *feature)
  

+{

• char res_path[PATH_MAX];
• char *res;
• FILE *inf;
• if (!feature) return true;

Doesn't this mean that resctrl_mon_feature_exists(NULL, NULL) will return true?

@@ -740,9 +755,35 @@ bool validate_resctrl_feature_request(const char *resource, const char *feature) return !!res; } +/*

• • resctrl_cache_feature_exists - Check if a file that indicates a
• • cache related feature support is present.

Seems like this is not really specific to a cache ... it can check for any info file related to any resource.

• • @resource: Required cache resource (L3 or L2)
• • @feature: Required cache feature.

This seems to assume some usage of this utility. What if it is, for example, resource_info_file_exists() or resource_info_file_readable()?

• • Return: True if the feature is supported, else false.
• */

+bool resctrl_cache_feature_exists(const char *resource,

• 		  const char *feature)
  

+{

• char res_path[PATH_MAX];
• struct stat statbuf;
• if (!feature)

• return true;
  

resctrl_cache_feature_exists(NULL, NULL) will return true, no?

• snprintf(res_path, sizeof(res_path), "%s/%s/%s", INFO_PATH, resource,

•  feature);
  

• if (stat(res_path, &statbuf))

• return false;
  

I think it will be more robust to look at statbuf to learn if the file type is correct and the file is actually readable.

• return true;

+}

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)

Reinette