Hi Peter, On 4/21/2023 7:17 AM, Peter Newman wrote: > 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. Please note that the changelog refers to "whether the soft RMID static key is enabled" but the patch uses a bool instead of a static key. > > Signed-off-by: Peter Newman <peternewman@xxxxxxxxxx> > --- > 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); > + } The above is not clear to me. If rr->first is true then it would read soft_rmid_bytes and then immediately reset it? Reinette