On Fri, Aug 11, 2023 at 10:33:18AM -0700, Reinette Chatre wrote: > Hi Tony, > > On 7/22/2023 12:07 PM, Tony Luck wrote: > > With Sub-NUMA Cluster mode enabled the scope of monitoring resources is > > per-NODE instead of per-L3 cache. Suffixes of directories with "L3" in > > their name refer to Sub-NUMA nodes instead of L3 cache ids. > > > > Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx> > > Reviewed-by: Peter Newman <peternewman@xxxxxxxxxx> > > --- > > Documentation/arch/x86/resctrl.rst | 10 +++++++--- > > 1 file changed, 7 insertions(+), 3 deletions(-) > > > > diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst > > index cb05d90111b4..4d9ddb91751d 100644 > > --- a/Documentation/arch/x86/resctrl.rst > > +++ b/Documentation/arch/x86/resctrl.rst > > @@ -345,9 +345,13 @@ When control is enabled all CTRL_MON groups will also contain: > > When monitoring is enabled all MON groups will also contain: > > > > "mon_data": > > - This contains a set of files organized by L3 domain and by > > - RDT event. E.g. on a system with two L3 domains there will > > - be subdirectories "mon_L3_00" and "mon_L3_01". Each of these > > + This contains a set of files organized by L3 domain or by NUMA > > + node (depending on whether Sub-NUMA Cluster (SNC) mode is disabled > > + or enabled respectively) and by RDT event. E.g. on a system with > > + SNC mode disabled with two L3 domains there will be subdirectories > > + "mon_L3_00" and "mon_L3_01". The numerical suffix refers to the > > + L3 cache id. With SNC enabled the directory names are the same, > > + but the numerical suffix refers to the node id. Each of these > > directories have one file per event (e.g. "llc_occupancy", > > "mbm_total_bytes", and "mbm_local_bytes"). In a MON group these > > files provide a read out of the current value of the event for > > I think it would be helpful to add a modified version of the snippet > (from previous patch changelog) regarding well-behaved NUMA apps. > With the above it may be confusing that a single cache allocation has > multiple cache occupancy counters. > > This also changes the meaning of the numbers in the directory names. > The documentation already provides guidance on how to find the cache > ID of a logical CPU (see section "Cache IDs"). I think it will be > helpful to add a snippet that makes it clear to users how to map > a CPU to its node ID. Added extra details as suggested. > > Reinette -Tony
