Commits
Vikas Shivappa committed edf6fa1c4a9
x86/intel_rdt/cqm: Add RMID (Resource monitoring ID) management Hardware uses RMID(Resource monitoring ID) to keep track of each of the RDT events associated with tasks. The number of RMIDs is dependent on the SKU and is enumerated via CPUID. We add support to manage the RMIDs which include managing the RMID allocation and reading LLC occupancy for an RMID. RMID allocation is managed by keeping a free list which is initialized to all available RMIDs except for RMID 0 which is always reserved for root group. RMIDs goto a limbo list once they are freed since the RMIDs are still tagged to cache lines of the tasks which were using them - thereby still having some occupancy. They continue to be in limbo list until the occupancy < threshold_occupancy. The threshold_occupancy is a user configurable value. OS uses IA32_QM_CTR MSR to read the occupancy associated with an RMID after programming the IA32_EVENTSEL MSR with the RMID. [Tony: Improved limbo search] Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: tony.luck@intel.com Cc: fenghua.yu@intel.com Cc: peterz@infradead.org Cc: eranian@google.com Cc: vikas.shivappa@intel.com Cc: ak@linux.intel.com Cc: davidcc@google.com Cc: reinette.chatre@intel.com Link: http://lkml.kernel.org/r/1501017287-28083-10-git-send-email-vikas.shivappa@linux.intel.com