diff options
Diffstat (limited to 'arch/x86/kernel/cpu')
| -rw-r--r-- | arch/x86/kernel/cpu/resctrl/monitor.c | 56 |
1 files changed, 50 insertions, 6 deletions
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index 89d7e6fcbaa1..ff4e74594a19 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -97,6 +97,8 @@ unsigned int resctrl_rmid_realloc_limit; #define CF(cf) ((unsigned long)(1048576 * (cf) + 0.5)) +static int snc_nodes_per_l3_cache = 1; + /* * The correction factor table is documented in Documentation/arch/x86/resctrl.rst. * If rmid > rmid threshold, MBM total and local values should be multiplied @@ -185,7 +187,43 @@ static inline struct rmid_entry *__rmid_entry(u32 idx) return entry; } -static int __rmid_read(u32 rmid, enum resctrl_event_id eventid, u64 *val) +/* + * When Sub-NUMA Cluster (SNC) mode is not enabled (as indicated by + * "snc_nodes_per_l3_cache == 1") no translation of the RMID value is + * needed. The physical RMID is the same as the logical RMID. + * + * On a platform with SNC mode enabled, Linux enables RMID sharing mode + * via MSR 0xCA0 (see the "RMID Sharing Mode" section in the "Intel + * Resource Director Technology Architecture Specification" for a full + * description of RMID sharing mode). + * + * In RMID sharing mode there are fewer "logical RMID" values available + * to accumulate data ("physical RMIDs" are divided evenly between SNC + * nodes that share an L3 cache). Linux creates an rdt_mon_domain for + * each SNC node. + * + * The value loaded into IA32_PQR_ASSOC is the "logical RMID". + * + * Data is collected independently on each SNC node and can be retrieved + * using the "physical RMID" value computed by this function and loaded + * into IA32_QM_EVTSEL. @cpu can be any CPU in the SNC node. + * + * The scope of the IA32_QM_EVTSEL and IA32_QM_CTR MSRs is at the L3 + * cache. So a "physical RMID" may be read from any CPU that shares + * the L3 cache with the desired SNC node, not just from a CPU in + * the specific SNC node. + */ +static int logical_rmid_to_physical_rmid(int cpu, int lrmid) +{ + struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl; + + if (snc_nodes_per_l3_cache == 1) + return lrmid; + + return lrmid + (cpu_to_node(cpu) % snc_nodes_per_l3_cache) * r->num_rmid; +} + +static int __rmid_read_phys(u32 prmid, enum resctrl_event_id eventid, u64 *val) { u64 msr_val; @@ -197,7 +235,7 @@ static int __rmid_read(u32 rmid, enum resctrl_event_id eventid, u64 *val) * IA32_QM_CTR.Error (bit 63) and IA32_QM_CTR.Unavailable (bit 62) * are error bits. */ - wrmsr(MSR_IA32_QM_EVTSEL, eventid, rmid); + wrmsr(MSR_IA32_QM_EVTSEL, eventid, prmid); rdmsrl(MSR_IA32_QM_CTR, msr_val); if (msr_val & RMID_VAL_ERROR) @@ -233,14 +271,17 @@ void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_mon_domain *d, enum resctrl_event_id eventid) { struct rdt_hw_mon_domain *hw_dom = resctrl_to_arch_mon_dom(d); + int cpu = cpumask_any(&d->hdr.cpu_mask); struct arch_mbm_state *am; + u32 prmid; am = get_arch_mbm_state(hw_dom, rmid, eventid); if (am) { memset(am, 0, sizeof(*am)); + prmid = logical_rmid_to_physical_rmid(cpu, rmid); /* Record any initial, non-zero count value. */ - __rmid_read(rmid, eventid, &am->prev_msr); + __rmid_read_phys(prmid, eventid, &am->prev_msr); } } @@ -275,8 +316,10 @@ int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_mon_domain *d, { struct rdt_hw_mon_domain *hw_dom = resctrl_to_arch_mon_dom(d); struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r); + int cpu = cpumask_any(&d->hdr.cpu_mask); struct arch_mbm_state *am; u64 msr_val, chunks; + u32 prmid; int ret; resctrl_arch_rmid_read_context_check(); @@ -284,7 +327,8 @@ int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_mon_domain *d, if (!cpumask_test_cpu(smp_processor_id(), &d->hdr.cpu_mask)) return -EINVAL; - ret = __rmid_read(rmid, eventid, &msr_val); + prmid = logical_rmid_to_physical_rmid(cpu, rmid); + ret = __rmid_read_phys(prmid, eventid, &msr_val); if (ret) return ret; @@ -1022,8 +1066,8 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r) int ret; resctrl_rmid_realloc_limit = boot_cpu_data.x86_cache_size * 1024; - hw_res->mon_scale = boot_cpu_data.x86_cache_occ_scale; - r->num_rmid = boot_cpu_data.x86_cache_max_rmid + 1; + hw_res->mon_scale = boot_cpu_data.x86_cache_occ_scale / snc_nodes_per_l3_cache; + r->num_rmid = (boot_cpu_data.x86_cache_max_rmid + 1) / snc_nodes_per_l3_cache; hw_res->mbm_width = MBM_CNTR_WIDTH_BASE; if (mbm_offset > 0 && mbm_offset <= MBM_CNTR_WIDTH_OFFSET_MAX) |