Hi Peter, On 7/26/24 3:48 PM, Peter Newman wrote:
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
It is not obvious to me that counter assignment supported per-domain requires allocation per-domain. I think this may get complicated when resources are monitored with one counter when tasks run in one domain and another counter when the same tasks run in another domain.
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.
As I understand this is separate from how the counter is allocated, but instead just a gap in current implementation of intended interface.
# 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=_;
Thank you very much for trying this out. Reinette
