Hi Babu,
On 8/14/25 7:25 PM, Babu Moger wrote:
> diff --git a/fs/resctrl/monitor.c b/fs/resctrl/monitor.c
> index 25fec9bf2d61..9201fedd2796 100644
> --- a/fs/resctrl/monitor.c
> +++ b/fs/resctrl/monitor.c
> @@ -1029,6 +1029,125 @@ int event_filter_show(struct kernfs_open_file *of, struct seq_file *seq, void *v
> return ret;
> }
>
> +static int resctrl_parse_mem_transactions(char *tok, u32 *val)
> +{
> + u32 temp_val = 0;
> + char *evt_str;
> + bool found;
> + int i;
> +
> +next_config:
> + if (!tok || tok[0] == '\0') {
> + *val = temp_val;
> + return 0;
> + }
Looks like resctrl_parse_mem_transactions() can return "success" with a parsed
return value of "0" (*val = 0) ... (follow-up comment in event_filter_write()).
> +
> + /* Start processing the strings for each memory transaction type */
> + evt_str = strim(strsep(&tok, ","));
> + found = false;
> + for (i = 0; i < NUM_MBM_TRANSACTIONS; i++) {
> + if (!strcmp(mbm_transactions[i].name, evt_str)) {
> + temp_val |= mbm_transactions[i].val;
> + found = true;
> + break;
> + }
> + }
> +
> + if (!found) {
> + rdt_last_cmd_printf("Invalid memory transaction type %s\n", evt_str);
> + return -EINVAL;
> + }
> +
> + goto next_config;
> +}
> +
> +/*
> + * rdtgroup_update_cntr_event - Update the counter assignments for the event
> + * in a group.
> + * @r: Resource to which update needs to be done.
> + * @rdtgrp: Resctrl group.
> + * @evtid: MBM monitor event.
> + */
> +static void rdtgroup_update_cntr_event(struct rdt_resource *r, struct rdtgroup *rdtgrp,
> + enum resctrl_event_id evtid)
> +{
> + struct rdt_mon_domain *d;
> + struct mbm_state *m;
> + int cntr_id;
> +
> + list_for_each_entry(d, &r->mon_domains, hdr.list) {
> + cntr_id = mbm_cntr_get(r, d, rdtgrp, evtid);
> + if (cntr_id >= 0) {
> + resctrl_arch_config_cntr(r, d, evtid, rdtgrp->mon.rmid,
> + rdtgrp->closid, cntr_id, true);
> + m = get_mbm_state(d, rdtgrp->closid, rdtgrp->mon.rmid, evtid);
> + if (m)
> + memset(m, 0, sizeof(*m));
This looks like open code of rdtgroup_assign_cntr()?
> + }
> + }
> +}
> +
...
> +
> +ssize_t event_filter_write(struct kernfs_open_file *of, char *buf, size_t nbytes,
> + loff_t off)
> +{
> + struct mon_evt *mevt = rdt_kn_parent_priv(of->kn);
> + struct rdt_resource *r;
> + u32 evt_cfg = 0;
> + int ret = 0;
> +
> + /* Valid input requires a trailing newline */
> + if (nbytes == 0 || buf[nbytes - 1] != '\n')
> + return -EINVAL;
> +
> + buf[nbytes - 1] = '\0';
> +
> + cpus_read_lock();
> + mutex_lock(&rdtgroup_mutex);
> +
> + rdt_last_cmd_clear();
> +
> + r = resctrl_arch_get_resource(mevt->rid);
> + if (!resctrl_arch_mbm_cntr_assign_enabled(r)) {
> + rdt_last_cmd_puts("mbm_event counter assignment mode is not enabled\n");
> + ret = -EINVAL;
> + goto out_unlock;
> + }
> +
> + ret = resctrl_parse_mem_transactions(buf, &evt_cfg);
> + if (!ret && mevt->evt_cfg != evt_cfg) {
... is evt_cfg of 0 (a) a valid value (that will not cause hardware to fault) and
(b) a reasonable value to allow?
Reinette
