On 2/21/2025 12:35 PM, Reinette Chatre wrote:
Hi James,
On 2/21/25 10:07 AM, James Morse wrote:
Hi Babu,
On 22/01/2025 20:20, Babu Moger wrote:
In mbm_cntr_assign mode hardware counters are assigned/unassigned to an
MBM event of a monitor group. Hardware counters are assigned/unassigned
at monitoring domain level.
Manage a monitoring domain's hardware counters using a per monitoring
domain array of struct mbm_cntr_cfg that is indexed by the hardware
counter ID. A hardware counter's configuration contains the MBM event
ID and points to the monitoring group that it is assigned to, with a
NULL pointer meaning that the hardware counter is available for assignment.
There is no direct way to determine which hardware counters are assigned
to a particular monitoring group. Check every entry of every hardware
counter configuration array in every monitoring domain to query which
MBM events of a monitoring group is tracked by hardware. Such queries
are acceptable because of a very small number of assignable counters.
diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index 511cfce8fc21..9a54e307d340 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -94,6 +94,18 @@ struct rdt_ctrl_domain {
u32 *mbps_val;
};
+/**
+ * struct mbm_cntr_cfg - assignable counter configuration
+ * @evtid: MBM event to which the counter is assigned. Only valid
+ * if @rdtgroup is not NULL.
+ * @rdtgroup: resctrl group assigned to the counter. NULL if the
+ * counter is free.
+ */
+struct mbm_cntr_cfg {
+ enum resctrl_event_id evtid;
+ struct rdtgroup *rdtgrp;
+};
struct rdtgroup here suggests this shouldn't be something the arch code is touching.
If its not needed by any arch specific code, (I couldn't find a resctrl_arch helper that
takes this) - could it be moved to resctrl's internal.h.
(If this does need to be visible to the arch code, one option would be to replace rdtgroup
with the closid/rmid, and a valid flag so that memset() continues to reset these entries)
Thank you for catching this!
Reinette
Sure. Will move it to arch/x86/kernel/cpu/resctrl/internal.h.
thanks
Babu
