Hi Tony, On 3/7/2024 3:16 PM, Tony Luck wrote: > On Thu, Mar 07, 2024 at 02:39:08PM -0800, Reinette Chatre wrote: >> Thank you for the example. I find that significantly easier to >> understand than a single number in a generic "nodes_per_l3_cache". >> Especially with potential confusion surrounding inconsistent "nodes" >> between allocation and monitoring. >> >> How about domain_cpu_list and domain_cpu_map ? > > Reinette, > > Like this (my test system doesn't have SNC, so all domains are the same): > > $ cd /sys/fs/resctrl/info/ > $ grep . */domain* > L3/domain_cpu_list:0: 0-35,72-107 > L3/domain_cpu_list:1: 36-71,108-143 > L3/domain_cpu_map:0: 0000,00000fff,ffffff00,0000000f,ffffffff > L3/domain_cpu_map:1: ffff,fffff000,000000ff,fffffff0,00000000 > L3_MON/domain_cpu_list:0: 0-35,72-107 > L3_MON/domain_cpu_list:1: 36-71,108-143 > L3_MON/domain_cpu_map:0: 0000,00000fff,ffffff00,0000000f,ffffffff > L3_MON/domain_cpu_map:1: ffff,fffff000,000000ff,fffffff0,00000000 > MB/domain_cpu_list:0: 0-35,72-107 > MB/domain_cpu_list:1: 36-71,108-143 > MB/domain_cpu_map:0: 0000,00000fff,ffffff00,0000000f,ffffffff > MB/domain_cpu_map:1: ffff,fffff000,000000ff,fffffff0,00000000 > > > The patch to do this is pretty straightforward. > Thank you for looking into this. This looks like valuable information for user space. Back to what started this discussion ... I expect user space can compare CPUs associated with control and monitoring domains to learn if SNC is enabled? (And now existence of domain_cpu_list and/or domain_cpu_map can also be used to determine if kernel supports SNC). Reinette
