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authorTony Luck <tony.luck@intel.com>2025-12-17 09:20:58 -0800
committerBorislav Petkov (AMD) <bp@alien8.de>2026-01-05 15:38:07 +0100
commitab0308aee3819a3eccde42f9eb5bb01d6733be38 (patch)
treeb21ee291be107584f6dc685c9c3ed5ba4f0f2912 /fs/resctrl
parentdd110880e80d35ad07e460e7a8da007c8058e7bf (diff)
x86,fs/resctrl: Handle events that can be read from any CPU
resctrl assumes that monitor events can only be read from a CPU in the cpumask_t set of each domain. This is true for x86 events accessed with an MSR interface, but may not be true for other access methods such as MMIO. Introduce and use flag mon_evt::any_cpu, settable by architecture, that indicates there are no restrictions on which CPU can read that event. This flag is not supported by the L3 event reading that requires to be run on a CPU that belongs to the L3 domain of the event being read. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com
Diffstat (limited to 'fs/resctrl')
-rw-r--r--fs/resctrl/ctrlmondata.c6
-rw-r--r--fs/resctrl/internal.h2
-rw-r--r--fs/resctrl/monitor.c4
3 files changed, 11 insertions, 1 deletions
diff --git a/fs/resctrl/ctrlmondata.c b/fs/resctrl/ctrlmondata.c
index 7f9b2fed117a..2c69fcd70eeb 100644
--- a/fs/resctrl/ctrlmondata.c
+++ b/fs/resctrl/ctrlmondata.c
@@ -578,6 +578,11 @@ void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,
}
}
+ if (evt->any_cpu) {
+ mon_event_count(rr);
+ goto out_ctx_free;
+ }
+
cpu = cpumask_any_housekeeping(cpumask, RESCTRL_PICK_ANY_CPU);
/*
@@ -591,6 +596,7 @@ void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,
else
smp_call_on_cpu(cpu, smp_mon_event_count, rr, false);
+out_ctx_free:
if (rr->arch_mon_ctx)
resctrl_arch_mon_ctx_free(r, evt->evtid, rr->arch_mon_ctx);
}
diff --git a/fs/resctrl/internal.h b/fs/resctrl/internal.h
index 86cf38ab08a7..fb0b6e40d022 100644
--- a/fs/resctrl/internal.h
+++ b/fs/resctrl/internal.h
@@ -61,6 +61,7 @@ static inline struct rdt_fs_context *rdt_fc2context(struct fs_context *fc)
* READS_TO_REMOTE_MEM) being tracked by @evtid.
* Only valid if @evtid is an MBM event.
* @configurable: true if the event is configurable
+ * @any_cpu: true if the event can be read from any CPU
* @enabled: true if the event is enabled
*/
struct mon_evt {
@@ -69,6 +70,7 @@ struct mon_evt {
char *name;
u32 evt_cfg;
bool configurable;
+ bool any_cpu;
bool enabled;
};
diff --git a/fs/resctrl/monitor.c b/fs/resctrl/monitor.c
index 340b847ab397..8c76ac133bca 100644
--- a/fs/resctrl/monitor.c
+++ b/fs/resctrl/monitor.c
@@ -518,6 +518,7 @@ static int __mon_event_count(struct rdtgroup *rdtgrp, struct rmid_read *rr)
{
switch (rr->r->rid) {
case RDT_RESOURCE_L3:
+ WARN_ON_ONCE(rr->evt->any_cpu);
if (rr->hdr)
return __l3_mon_event_count(rdtgrp, rr);
else
@@ -987,7 +988,7 @@ struct mon_evt mon_event_all[QOS_NUM_EVENTS] = {
},
};
-void resctrl_enable_mon_event(enum resctrl_event_id eventid)
+void resctrl_enable_mon_event(enum resctrl_event_id eventid, bool any_cpu)
{
if (WARN_ON_ONCE(eventid < QOS_FIRST_EVENT || eventid >= QOS_NUM_EVENTS))
return;
@@ -996,6 +997,7 @@ void resctrl_enable_mon_event(enum resctrl_event_id eventid)
return;
}
+ mon_event_all[eventid].any_cpu = any_cpu;
mon_event_all[eventid].enabled = true;
}