Hi Babu,
On 6/13/25 2:05 PM, Babu Moger wrote:
> BMEC (Bandwidth Monitoring Event Configuration) and mbm_event mode do not
> work simultaneously.
Could you please elaborate why they do not work simultaneously?
>
> When mbm_event mode is enabled, hide BMEC-related files to avoid confusion
> and update the mon_features display accordingly.
>
> The files /sys/fs/resctrl/info/L3_MON/mbm_total_bytes_config and
> /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config will not be visible
> when mbm_event mode is enabled.
>
> Suggested-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
> Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
> ---
> v14: Updated the changelog for change in mbm_assign_modes.
> Added check in rdt_mon_features_show to hide bmec related feature.
>
> v13: New patch to hide BMEC related files.
> ---
> fs/resctrl/rdtgroup.c | 42 +++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 41 insertions(+), 1 deletion(-)
>
> diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c
> index 92bb8f3adfae..8c67e0897f25 100644
> --- a/fs/resctrl/rdtgroup.c
> +++ b/fs/resctrl/rdtgroup.c
> @@ -1164,7 +1164,8 @@ static int rdt_mon_features_show(struct kernfs_open_file *of,
> if (mevt->rid != r->rid || !mevt->enabled)
> continue;
> seq_printf(seq, "%s\n", mevt->name);
> - if (mevt->configurable)
> + if (mevt->configurable &&
> + !resctrl_arch_mbm_cntr_assign_enabled(r))
> seq_printf(seq, "%s_config\n", mevt->name);
> }
>
> @@ -1813,6 +1814,38 @@ static ssize_t mbm_local_bytes_config_write(struct kernfs_open_file *of,
> return ret ?: nbytes;
> }
>
> +/**
> + * resctrl_bmec_files_show() — Controls the visibility of BMEC-related resctrl
> + * files. When @show is true, the files are displayed; when false, the files
> + * are hidden.
> + */
> +static void resctrl_bmec_files_show(struct rdt_resource *r, bool show)
> +{
> + struct kernfs_node *kn_config, *l3_mon_kn;
> + char name[32];
> +
> + sprintf(name, "%s_MON", r->name);
> + l3_mon_kn = kernfs_find_and_get(kn_info, name);
Similar to comment about resctrl_mkdir_counter_configs() (resctrl_mkdir_event_configs())
I think this can be avoided by calling resctrl_bmec_files_show() from
rdtgroup_mkdir_info_resdir().
> + if (!l3_mon_kn)
> + return;
> +
> + kn_config = kernfs_find_and_get(l3_mon_kn, "mbm_total_bytes_config");
> + if (kn_config) {
> + kernfs_get(kn_config);
Be careful ... kernfs_find_and_get() already took a reference. Additional
kernfs_get() is not needed.
> + kernfs_show(kn_config, show);
> + kernfs_put(kn_config);
> + }
> +
> + kn_config = kernfs_find_and_get(l3_mon_kn, "mbm_local_bytes_config");
> + if (kn_config) {
> + kernfs_get(kn_config);
> + kernfs_show(kn_config, show);
> + kernfs_put(kn_config);
> + }
> +
> + kernfs_put(l3_mon_kn);
> +}
> +
> static int resctrl_mbm_assign_mode_show(struct kernfs_open_file *of,
> struct seq_file *s, void *v)
> {
> @@ -2808,6 +2841,13 @@ static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn)
> ret = resctrl_mkdir_counter_configs(r, name);
> if (ret)
> goto out_destroy;
> +
> + /*
> + * Hide BMEC related files if mbm_event mode
> + * is enabled.
> + */
> + if (resctrl_arch_mbm_cntr_assign_enabled(r))
> + resctrl_bmec_files_show(r, false);
> }
> }
>
Reinette
