When RMIDs are soft, __mon_event_count() only needs to report the current byte count in memory and should not touch the hardware RMIDs.
Create a parallel version for the soft RMID configuration and update __mon_event_count() to choose between it and the original depending on whether the soft RMID static key is enabled.
Signed-off-by: Peter Newman peternewman@google.com --- arch/x86/kernel/cpu/resctrl/monitor.c | 33 ++++++++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index bb857eefa3b0..3d54a634471a 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -487,7 +487,30 @@ void resctrl_mbm_flush_cpu(void) __mbm_flush(QOS_L3_MBM_TOTAL_EVENT_ID, r, d); }
-static int __mon_event_count(u32 rmid, struct rmid_read *rr) +static int __mon_event_count_soft_rmid(u32 rmid, struct rmid_read *rr) +{ + struct mbm_state *m; + + WARN_ON(!is_mbm_event(rr->evtid)); + m = get_mbm_state(rr->d, rmid, rr->evtid); + if (!m) + /* implies !is_mbm_event(...) */ + return -1; + + rr->val += atomic64_read(&m->soft_rmid_bytes); + + if (rr->first) { + /* + * Discard any bandwidth resulting from the initial HW counter + * reads. + */ + atomic64_set(&m->soft_rmid_bytes, 0); + } + + return 0; +} + +static int __mon_event_count_default(u32 rmid, struct rmid_read *rr) { struct mbm_state *m; u64 tval = 0; @@ -509,6 +532,14 @@ static int __mon_event_count(u32 rmid, struct rmid_read *rr) return 0; }
+static int __mon_event_count(u32 rmid, struct rmid_read *rr) +{ + if (rdt_mon_soft_rmid) + return __mon_event_count_soft_rmid(rmid, rr); + else + return __mon_event_count_default(rmid, rr); +} + /* * mbm_bw_count() - Update bw count from values previously read by * __mon_event_count().