diff options
Diffstat (limited to 'arch/x86/kernel/cpu/resctrl/monitor.c')
| -rw-r--r-- | arch/x86/kernel/cpu/resctrl/monitor.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index ca486d00541e..16b7bf5a048d 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -1090,6 +1090,26 @@ static void l3_mon_evt_init(struct rdt_resource *r) list_add_tail(&mbm_local_event.list, &r->evt_list); } +/* + * The power-on reset value of MSR_RMID_SNC_CONFIG is 0x1 + * which indicates that RMIDs are configured in legacy mode. + * This mode is incompatible with Linux resctrl semantics + * as RMIDs are partitioned between SNC nodes, which requires + * a user to know which RMID is allocated to a task. + * Clearing bit 0 reconfigures the RMID counters for use + * in RMID sharing mode. This mode is better for Linux. + * The RMID space is divided between all SNC nodes with the + * RMIDs renumbered to start from zero in each node when + * counting operations from tasks. Code to read the counters + * must adjust RMID counter numbers based on SNC node. See + * logical_rmid_to_physical_rmid() for code that does this. + */ +void arch_mon_domain_online(struct rdt_resource *r, struct rdt_mon_domain *d) +{ + if (snc_nodes_per_l3_cache > 1) + msr_clear_bit(MSR_RMID_SNC_CONFIG, 0); +} + int __init rdt_get_mon_l3_config(struct rdt_resource *r) { unsigned int mbm_offset = boot_cpu_data.x86_cache_mbm_width_offset; |