Hi Babu, On 06/08/2024 23:00, Babu Moger wrote: > Hardware provides a set of counters when mbm_cntr_assignable feature is > supported. These counters are used for assigning the events in resctrl > group when the feature is enabled. > > Introduce mbm_cntrs_free_map bitmap to track available and free counters > and set of routines to allocate and free the counters. > diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c > index ab4fab3b7cf1..c818965e36c9 100644 > --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c > +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c > @@ -185,6 +185,37 @@ bool closid_allocated(unsigned int closid) > return !test_bit(closid, &closid_free_map); > } > > +/* > + * Counter bitmap for tracking the 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 DECLARE_BITMAP(mbm_cntrs_free_map, 64); Please make this resctrl limit of '64' a define in linux/resctrl.h so the arch code knows what the limit is! MPAM platforms may have more than this - and really bad things happen if mbm_cntrs_init() passes bitmap_fill() a value greater than 64. Even better - could we dynamically allocate this bitmap using the size advertised by the architecture code? Thanks, James
