Re: [PATCH v5 13/16] selftests/resctrl: Convert ctrlgrp & mongrp to pointers

From: Reinette Chatre
Date: Fri May 31 2024 - 14:18:36 EST


Hi Ilpo,

On 5/31/24 6:11 AM, Ilpo Järvinen wrote:
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.

Convert !grp_name check in create_grp() into internal sanity check by
returning error if the caller asked to create a group but doesn't
provide a name for the group. The existing code already abides this by
only calling create_grp() if mongrp is non-NULL so the error should
never be returned with the current selftests (ctrlgrp is never NULL).

This paragraph is no longer relevant and can be dropped.


Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
---
v5:
- Return 0 if grp_name is null (restore earlier behavior)
- Move the root group note from comment into kerneldoc

v3:
- Removed wrong comment
- Changed grp_name check to return -1 on fail (internal sanity check)
---
tools/testing/selftests/resctrl/resctrl.h | 4 ++--
tools/testing/selftests/resctrl/resctrlfs.c | 16 +++++++---------
2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
index 5967389038d4..a999fbc13fd3 100644
--- 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 f4dc8ef23a8c..893041faaf18 100644
--- 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 success.

"always results success" -> "always results in success"?

With changelog and comment fixups addressed:
| Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>

Reinette