Hi Tony, On 10/10/24 13:57, Luck, Tony wrote: >>> Why have this complexity in mbm_assign_control syntax? >> >> Lets take an example: >> $ cat /sys/fs/resctrl/info/L3_MON/num_mbm_cntrs >> Total 32 >> Available 30 >> >> # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control >> //0=tl;1=tl; >> >> Here default group has taken two counters. >> >> # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control >> //0=_;1=tl; >> >> Here default group has two counters. >> Domain 0 does not have counters applied. So, you wont be able to read the >> MBM values for domain 0. >> Domain 1 has both the counters applied. > > Is there some benefit from doing this? You are still using the same > number of counters. You now can't read them from domain 0. > > You said the counters are system-wide. Does that mean that in > this case: Counter are system wide. We also keep track if the counters is applied to specific domain or not. We have two bitmaps to keep track of this. There is a cost to applying counter to the domain(IPI needs to be sent to the domain). > > # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control > //0=tl;1=tl; > > there aren't separate counts from each of domain 0 and domain 1. Yes. There is. Each domain has its own count. I am not sure about your config. # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control //0=_;1=tl; # grep . /sys/fs/resctrl/mon_data/*/*total* /sys/fs/resctrl/mon_data/mon_L3_00/mbm_total_bytes:Unassigned /sys/fs/resctrl/mon_data/mon_L3_01/mbm_total_bytes:22976 > I.e. if I read both I'd see the same value (sum of traffic on both domains): > > $ grep . /sys/fs/resctrl/mon_data/*/*total* > /sys/fs/resctrl /mon_data/mon_L3_00/mbm_total_bytes:260039467008 > /sys/fs/resctrl /mon_data/mon_L3_01/mbm_total_bytes:260039467008 > > -Tony -- Thanks Babu Moger
