Hi Babu, On Wed, Jul 3, 2024 at 2:50 PM Babu Moger <babu.moger@xxxxxxx> wrote: > diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c > index 4f47f52e01c2..b3d3fa048f15 100644 > --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c > +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c > @@ -185,6 +185,23 @@ bool closid_allocated(unsigned int closid) > return !test_bit(closid, &closid_free_map); > } > > +/* > + * Counter bitmap and its length for tracking available counters. > + * ABMC feature provides set of hardware counters for enabling events. > + * Each event takes one hardware counter. Kernel needs to keep track > + * of number of available counters. > + */ > +static unsigned long mbm_cntrs_free_map; > +static unsigned int mbm_cntrs_free_map_len; If counter assignment is supported at a per-domain granularity, then counter id allocation needs to be done per-domain rather than globally. For example, if I free a counter from one group in a particular domain, it should be available to allocate to another group only in that domain. When I attempt this using the current series, the resulting behavior is quite interesting. I noticed Reinette also commented on this later in the series, noticing that counters are only allocated permanently to groups and never move as a result of writing to mbm_control. # grep 'g1[45]' info/L3_MON/mbm_control test/g14/0=tl;1=tl;2=tl;3=tl;4=tl;5=tl;6=tl;7=tl;8=tl;9=tl;10=tl;11=tl;12=tl;13=tl;14=tl;15=tl;16=tl;17=tl;18=tl;19=tl;20=tl;21=tl;22=tl;23=tl;24=tl;25=tl;26=tl;27=tl;28=tl;29=tl;30=tl;31=tl; test/g15/0=_;1=_;2=_;3=_;4=_;5=_;6=_;7=_;8=_;9=_;10=_;11=_;12=_;13=_;14=_;15=_;16=_;17=_;18=_;19=_;20=_;21=_;22=_;23=_;24=_;25=_;26=_;27=_;28=_;29=_;30=_;31=_; [domains 2-31 omitted for clarity below] # echo 'test/g14/1-t' > info/L3_MON/mbm_control # grep 'g1[45]' info/L3_MON/mbm_control test/g14/0=tl;1=l; test/g15/0=_;1=_; # echo "test/g15/1+t" > info/L3_MON/mbm_control # grep 'g1[45]' info/L3_MON/mbm_control test/g14/0=tl;1=_; test/g15/0=_;1=_; -Peter
