selftests/resctrl: Convert ctrlgrp & mongrp to pointers

The struct resctrl_val_param has control and monitor groups as char
arrays but they are not supposed to be mutated within resctrl_val().

Convert the ctrlgrp and mongrp char array within resctrl_val_param to
plain const char pointers and adjust the strlen() based checks to
check NULL instead.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
index 5967389038d4be8004d1d2eb3aa4959248f2fa54..a999fbc13fd32158972718a2f9cae7e1b750c8d2 100644 (file)
--- a/tools/testing/selftests/resctrl/resctrl.h
+++ b/tools/testing/selftests/resctrl/resctrl.h
@@ -91,8 +91,8 @@ struct resctrl_test {
  */
 struct resctrl_val_param {
        char            *resctrl_val;
-       char            ctrlgrp[64];
-       char            mongrp[64];
+       const char      *ctrlgrp;
+       const char      *mongrp;
        char            filename[64];
        unsigned long   mask;
        int             num_of_runs;

diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
index f4dc8ef23a8c50fc113b06d7b73177ca3d1ba679..e2d1ecb55d51f60cc4b88c4109540db4a9cb76ac 100644 (file)
--- a/tools/testing/selftests/resctrl/resctrlfs.c
+++ b/tools/testing/selftests/resctrl/resctrlfs.c
@@ -456,6 +456,9 @@ int taskset_restore(pid_t bm_pid, cpu_set_t *old_affinity)
  * @grp:       Full path and name of the group
  * @parent_grp:        Full path and name of the parent group
  *
+ * Creates a group @grp_name if it does not exist yet. If @grp_name is NULL,
+ * it is interpreted as the root group which always results in success.
+ *
  * Return: 0 on success, < 0 on error.
  */
 static int create_grp(const char *grp_name, char *grp, const char *parent_grp)
@@ -464,12 +467,7 @@ static int create_grp(const char *grp_name, char *grp, const char *parent_grp)
        struct dirent *ep;
        DIR *dp;
 
-       /*
-        * At this point, we are guaranteed to have resctrl FS mounted and if
-        * length of grp_name == 0, it means, user wants to use root con_mon
-        * grp, so do nothing
-        */
-       if (strlen(grp_name) == 0)
+       if (!grp_name)
                return 0;
 
        /* Check if requested grp exists or not */
@@ -541,7 +539,7 @@ int write_bm_pid_to_resctrl(pid_t bm_pid, const char *ctrlgrp,
        char tasks[1024];
        int ret = 0;
 
-       if (strlen(ctrlgrp))
+       if (ctrlgrp)
                sprintf(controlgroup, "%s/%s", RESCTRL_PATH, ctrlgrp);
        else
                sprintf(controlgroup, "%s", RESCTRL_PATH);
@@ -558,7 +556,7 @@ int write_bm_pid_to_resctrl(pid_t bm_pid, const char *ctrlgrp,
        /* Create mon grp and write pid into it for "mbm" and "cmt" test */
        if (!strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR)) ||
            !strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR))) {
-               if (strlen(mongrp)) {
+               if (mongrp) {
                        sprintf(monitorgroup_p, "%s/mon_groups", controlgroup);
                        sprintf(monitorgroup, "%s/%s", monitorgroup_p, mongrp);
                        ret = create_grp(mongrp, monitorgroup, monitorgroup_p);
@@ -612,7 +610,7 @@ int write_schemata(const char *ctrlgrp, char *schemata, int cpu_no,
                goto out;
        }
 
-       if (strlen(ctrlgrp) != 0)
+       if (ctrlgrp)
                sprintf(controlgroup, "%s/%s/schemata", RESCTRL_PATH, ctrlgrp);
        else
                sprintf(controlgroup, "%s/schemata", RESCTRL_PATH);