Hi Babu, On 1/22/25 12:20 PM, Babu Moger wrote: > The mbm_cntr_assign mode provides an option to the user to assign a > counter to an RMID, event pair and monitor the bandwidth as long as > the counter is assigned. Number of assignments depend on number of > monitoring counters available. > > Provide the interface to display the number of monitoring counters > supported. The resctrl file 'num_mbm_cntrs' is visible to user space > when the system supports mbm_cntr_assign mode. > > Signed-off-by: Babu Moger <babu.moger@xxxxxxx> > --- ... > diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst > index b5defc5bce0e..31ff764deeeb 100644 > --- a/Documentation/arch/x86/resctrl.rst > +++ b/Documentation/arch/x86/resctrl.rst > @@ -283,6 +283,22 @@ with the following files: > "mbm_total_bytes" or "mbm_local_bytes" will report 'Unavailable' if > there is no counter associated with that event. > > +"num_mbm_cntrs": > + The number of monitoring counters available for assignment when the > + system supports mbm_cntr_assign mode. > + :: > + > + # cat /sys/fs/resctrl/info/L3_MON/num_mbm_cntrs > + 32 > + > + The resctrl file system supports tracking up to two memory bandwidth > + events per monitoring group: mbm_total_bytes and/or mbm_local_bytes. > + Up to two counters can be assigned per monitoring group, one for each > + memory bandwidth event. More monitoring groups can be tracked by > + assigning one counter per monitoring group. However, doing so limits > + memory bandwidth tracking to a single memory bandwidth event per > + monitoring group. > + This text needs an update to reflect the switch to per-domain counter assignment. Reinette
