Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
James Morse | 1425 | 32.83% | 28 | 34.15% |
Vikas Shivappa | 1389 | 32.00% | 13 | 15.85% |
Tony Luck | 728 | 16.77% | 11 | 13.41% |
Fenghua Yu | 424 | 9.77% | 6 | 7.32% |
Babu Moger | 174 | 4.01% | 9 | 10.98% |
Peter Newman | 101 | 2.33% | 2 | 2.44% |
Reinette Chatre | 61 | 1.41% | 3 | 3.66% |
haifeng.xu | 14 | 0.32% | 1 | 1.22% |
Prarit Bhargava | 7 | 0.16% | 1 | 1.22% |
Thomas Gleixner | 7 | 0.16% | 2 | 2.44% |
Dave P Martin | 4 | 0.09% | 1 | 1.22% |
Randy Dunlap | 3 | 0.07% | 1 | 1.22% |
Ingo Molnar | 1 | 0.02% | 1 | 1.22% |
Jonathan Corbet | 1 | 0.02% | 1 | 1.22% |
Andi Kleen | 1 | 0.02% | 1 | 1.22% |
Colin Ian King | 1 | 0.02% | 1 | 1.22% |
Total | 4341 | 82 |
// SPDX-License-Identifier: GPL-2.0-only /* * Resource Director Technology(RDT) * - Monitoring code * * Copyright (C) 2017 Intel Corporation * * Author: * Vikas Shivappa <vikas.shivappa@intel.com> * * This replaces the cqm.c based on perf but we reuse a lot of * code and datastructures originally from Peter Zijlstra and Matt Fleming. * * More information about RDT be found in the Intel (R) x86 Architecture * Software Developer Manual June 2016, volume 3, section 17.17. */ #define pr_fmt(fmt) "resctrl: " fmt #include <linux/cpu.h> #include <linux/module.h> #include <linux/sizes.h> #include <linux/slab.h> #include <asm/cpu_device_id.h> #include <asm/resctrl.h> #include "internal.h" #include "trace.h" /** * struct rmid_entry - dirty tracking for all RMID. * @closid: The CLOSID for this entry. * @rmid: The RMID for this entry. * @busy: The number of domains with cached data using this RMID. * @list: Member of the rmid_free_lru list when busy == 0. * * Depending on the architecture the correct monitor is accessed using * both @closid and @rmid, or @rmid only. * * Take the rdtgroup_mutex when accessing. */ struct rmid_entry { u32 closid; u32 rmid; int busy; struct list_head list; }; /* * @rmid_free_lru - A least recently used list of free RMIDs * These RMIDs are guaranteed to have an occupancy less than the * threshold occupancy */ static LIST_HEAD(rmid_free_lru); /* * @closid_num_dirty_rmid The number of dirty RMID each CLOSID has. * Only allocated when CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID is defined. * Indexed by CLOSID. Protected by rdtgroup_mutex. */ static u32 *closid_num_dirty_rmid; /* * @rmid_limbo_count - count of currently unused but (potentially) * dirty RMIDs. * This counts RMIDs that no one is currently using but that * may have a occupancy value > resctrl_rmid_realloc_threshold. User can * change the threshold occupancy value. */ static unsigned int rmid_limbo_count; /* * @rmid_entry - The entry in the limbo and free lists. */ static struct rmid_entry *rmid_ptrs; /* * Global boolean for rdt_monitor which is true if any * resource monitoring is enabled. */ bool rdt_mon_capable; /* * Global to indicate which monitoring events are enabled. */ unsigned int rdt_mon_features; /* * This is the threshold cache occupancy in bytes at which we will consider an * RMID available for re-allocation. */ unsigned int resctrl_rmid_realloc_threshold; /* * This is the maximum value for the reallocation threshold, in bytes. */ 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 * by the correction factor. * * The original table is modified for better code: * * 1. The threshold 0 is changed to rmid count - 1 so don't do correction * for the case. * 2. MBM total and local correction table indexed by core counter which is * equal to (x86_cache_max_rmid + 1) / 8 - 1 and is from 0 up to 27. * 3. The correction factor is normalized to 2^20 (1048576) so it's faster * to calculate corrected value by shifting: * corrected_value = (original_value * correction_factor) >> 20 */ static const struct mbm_correction_factor_table { u32 rmidthreshold; u64 cf; } mbm_cf_table[] __initconst = { {7, CF(1.000000)}, {15, CF(1.000000)}, {15, CF(0.969650)}, {31, CF(1.000000)}, {31, CF(1.066667)}, {31, CF(0.969650)}, {47, CF(1.142857)}, {63, CF(1.000000)}, {63, CF(1.185115)}, {63, CF(1.066553)}, {79, CF(1.454545)}, {95, CF(1.000000)}, {95, CF(1.230769)}, {95, CF(1.142857)}, {95, CF(1.066667)}, {127, CF(1.000000)}, {127, CF(1.254863)}, {127, CF(1.185255)}, {151, CF(1.000000)}, {127, CF(1.066667)}, {167, CF(1.000000)}, {159, CF(1.454334)}, {183, CF(1.000000)}, {127, CF(0.969744)}, {191, CF(1.280246)}, {191, CF(1.230921)}, {215, CF(1.000000)}, {191, CF(1.143118)}, }; static u32 mbm_cf_rmidthreshold __read_mostly = UINT_MAX; static u64 mbm_cf __read_mostly; static inline u64 get_corrected_mbm_count(u32 rmid, unsigned long val) { /* Correct MBM value. */ if (rmid > mbm_cf_rmidthreshold) val = (val * mbm_cf) >> 20; return val; } /* * x86 and arm64 differ in their handling of monitoring. * x86's RMID are independent numbers, there is only one source of traffic * with an RMID value of '1'. * arm64's PMG extends the PARTID/CLOSID space, there are multiple sources of * traffic with a PMG value of '1', one for each CLOSID, meaning the RMID * value is no longer unique. * To account for this, resctrl uses an index. On x86 this is just the RMID, * on arm64 it encodes the CLOSID and RMID. This gives a unique number. * * The domain's rmid_busy_llc and rmid_ptrs[] are sized by index. The arch code * must accept an attempt to read every index. */ static inline struct rmid_entry *__rmid_entry(u32 idx) { struct rmid_entry *entry; u32 closid, rmid; entry = &rmid_ptrs[idx]; resctrl_arch_rmid_idx_decode(idx, &closid, &rmid); WARN_ON_ONCE(entry->closid != closid); WARN_ON_ONCE(entry->rmid != rmid); return entry; } /* * 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; /* * As per the SDM, when IA32_QM_EVTSEL.EvtID (bits 7:0) is configured * with a valid event code for supported resource type and the bits * IA32_QM_EVTSEL.RMID (bits 41:32) are configured with valid RMID, * IA32_QM_CTR.data (bits 61:0) reports the monitored data. * IA32_QM_CTR.Error (bit 63) and IA32_QM_CTR.Unavailable (bit 62) * are error bits. */ wrmsr(MSR_IA32_QM_EVTSEL, eventid, prmid); rdmsrl(MSR_IA32_QM_CTR, msr_val); if (msr_val & RMID_VAL_ERROR) return -EIO; if (msr_val & RMID_VAL_UNAVAIL) return -EINVAL; *val = msr_val; return 0; } static struct arch_mbm_state *get_arch_mbm_state(struct rdt_hw_mon_domain *hw_dom, u32 rmid, enum resctrl_event_id eventid) { switch (eventid) { case QOS_L3_OCCUP_EVENT_ID: return NULL; case QOS_L3_MBM_TOTAL_EVENT_ID: return &hw_dom->arch_mbm_total[rmid]; case QOS_L3_MBM_LOCAL_EVENT_ID: return &hw_dom->arch_mbm_local[rmid]; } /* Never expect to get here */ WARN_ON_ONCE(1); return NULL; } void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_mon_domain *d, u32 unused, u32 rmid, 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_phys(prmid, eventid, &am->prev_msr); } } /* * Assumes that hardware counters are also reset and thus that there is * no need to record initial non-zero counts. */ void resctrl_arch_reset_rmid_all(struct rdt_resource *r, struct rdt_mon_domain *d) { struct rdt_hw_mon_domain *hw_dom = resctrl_to_arch_mon_dom(d); if (is_mbm_total_enabled()) memset(hw_dom->arch_mbm_total, 0, sizeof(*hw_dom->arch_mbm_total) * r->num_rmid); if (is_mbm_local_enabled()) memset(hw_dom->arch_mbm_local, 0, sizeof(*hw_dom->arch_mbm_local) * r->num_rmid); } static u64 mbm_overflow_count(u64 prev_msr, u64 cur_msr, unsigned int width) { u64 shift = 64 - width, chunks; chunks = (cur_msr << shift) - (prev_msr << shift); return chunks >> shift; } int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_mon_domain *d, u32 unused, u32 rmid, enum resctrl_event_id eventid, u64 *val, void *ignored) { 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(); prmid = logical_rmid_to_physical_rmid(cpu, rmid); ret = __rmid_read_phys(prmid, eventid, &msr_val); if (ret) return ret; am = get_arch_mbm_state(hw_dom, rmid, eventid); if (am) { am->chunks += mbm_overflow_count(am->prev_msr, msr_val, hw_res->mbm_width); chunks = get_corrected_mbm_count(rmid, am->chunks); am->prev_msr = msr_val; } else { chunks = msr_val; } *val = chunks * hw_res->mon_scale; return 0; } static void limbo_release_entry(struct rmid_entry *entry) { lockdep_assert_held(&rdtgroup_mutex); rmid_limbo_count--; list_add_tail(&entry->list, &rmid_free_lru); if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) closid_num_dirty_rmid[entry->closid]--; } /* * Check the RMIDs that are marked as busy for this domain. If the * reported LLC occupancy is below the threshold clear the busy bit and * decrement the count. If the busy count gets to zero on an RMID, we * free the RMID */ void __check_limbo(struct rdt_mon_domain *d, bool force_free) { struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl; u32 idx_limit = resctrl_arch_system_num_rmid_idx(); struct rmid_entry *entry; u32 idx, cur_idx = 1; void *arch_mon_ctx; bool rmid_dirty; u64 val = 0; arch_mon_ctx = resctrl_arch_mon_ctx_alloc(r, QOS_L3_OCCUP_EVENT_ID); if (IS_ERR(arch_mon_ctx)) { pr_warn_ratelimited("Failed to allocate monitor context: %ld", PTR_ERR(arch_mon_ctx)); return; } /* * Skip RMID 0 and start from RMID 1 and check all the RMIDs that * are marked as busy for occupancy < threshold. If the occupancy * is less than the threshold decrement the busy counter of the * RMID and move it to the free list when the counter reaches 0. */ for (;;) { idx = find_next_bit(d->rmid_busy_llc, idx_limit, cur_idx); if (idx >= idx_limit) break; entry = __rmid_entry(idx); if (resctrl_arch_rmid_read(r, d, entry->closid, entry->rmid, QOS_L3_OCCUP_EVENT_ID, &val, arch_mon_ctx)) { rmid_dirty = true; } else { rmid_dirty = (val >= resctrl_rmid_realloc_threshold); /* * x86's CLOSID and RMID are independent numbers, so the entry's * CLOSID is an empty CLOSID (X86_RESCTRL_EMPTY_CLOSID). On Arm the * RMID (PMG) extends the CLOSID (PARTID) space with bits that aren't * used to select the configuration. It is thus necessary to track both * CLOSID and RMID because there may be dependencies between them * on some architectures. */ trace_mon_llc_occupancy_limbo(entry->closid, entry->rmid, d->hdr.id, val); } if (force_free || !rmid_dirty) { clear_bit(idx, d->rmid_busy_llc); if (!--entry->busy) limbo_release_entry(entry); } cur_idx = idx + 1; } resctrl_arch_mon_ctx_free(r, QOS_L3_OCCUP_EVENT_ID, arch_mon_ctx); } bool has_busy_rmid(struct rdt_mon_domain *d) { u32 idx_limit = resctrl_arch_system_num_rmid_idx(); return find_first_bit(d->rmid_busy_llc, idx_limit) != idx_limit; } static struct rmid_entry *resctrl_find_free_rmid(u32 closid) { struct rmid_entry *itr; u32 itr_idx, cmp_idx; if (list_empty(&rmid_free_lru)) return rmid_limbo_count ? ERR_PTR(-EBUSY) : ERR_PTR(-ENOSPC); list_for_each_entry(itr, &rmid_free_lru, list) { /* * Get the index of this free RMID, and the index it would need * to be if it were used with this CLOSID. * If the CLOSID is irrelevant on this architecture, the two * index values are always the same on every entry and thus the * very first entry will be returned. */ itr_idx = resctrl_arch_rmid_idx_encode(itr->closid, itr->rmid); cmp_idx = resctrl_arch_rmid_idx_encode(closid, itr->rmid); if (itr_idx == cmp_idx) return itr; } return ERR_PTR(-ENOSPC); } /** * resctrl_find_cleanest_closid() - Find a CLOSID where all the associated * RMID are clean, or the CLOSID that has * the most clean RMID. * * MPAM's equivalent of RMID are per-CLOSID, meaning a freshly allocated CLOSID * may not be able to allocate clean RMID. To avoid this the allocator will * choose the CLOSID with the most clean RMID. * * When the CLOSID and RMID are independent numbers, the first free CLOSID will * be returned. */ int resctrl_find_cleanest_closid(void) { u32 cleanest_closid = ~0; int i = 0; lockdep_assert_held(&rdtgroup_mutex); if (!IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) return -EIO; for (i = 0; i < closids_supported(); i++) { int num_dirty; if (closid_allocated(i)) continue; num_dirty = closid_num_dirty_rmid[i]; if (num_dirty == 0) return i; if (cleanest_closid == ~0) cleanest_closid = i; if (num_dirty < closid_num_dirty_rmid[cleanest_closid]) cleanest_closid = i; } if (cleanest_closid == ~0) return -ENOSPC; return cleanest_closid; } /* * For MPAM the RMID value is not unique, and has to be considered with * the CLOSID. The (CLOSID, RMID) pair is allocated on all domains, which * allows all domains to be managed by a single free list. * Each domain also has a rmid_busy_llc to reduce the work of the limbo handler. */ int alloc_rmid(u32 closid) { struct rmid_entry *entry; lockdep_assert_held(&rdtgroup_mutex); entry = resctrl_find_free_rmid(closid); if (IS_ERR(entry)) return PTR_ERR(entry); list_del(&entry->list); return entry->rmid; } static void add_rmid_to_limbo(struct rmid_entry *entry) { struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl; struct rdt_mon_domain *d; u32 idx; lockdep_assert_held(&rdtgroup_mutex); /* Walking r->domains, ensure it can't race with cpuhp */ lockdep_assert_cpus_held(); idx = resctrl_arch_rmid_idx_encode(entry->closid, entry->rmid); entry->busy = 0; list_for_each_entry(d, &r->mon_domains, hdr.list) { /* * For the first limbo RMID in the domain, * setup up the limbo worker. */ if (!has_busy_rmid(d)) cqm_setup_limbo_handler(d, CQM_LIMBOCHECK_INTERVAL, RESCTRL_PICK_ANY_CPU); set_bit(idx, d->rmid_busy_llc); entry->busy++; } rmid_limbo_count++; if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) closid_num_dirty_rmid[entry->closid]++; } void free_rmid(u32 closid, u32 rmid) { u32 idx = resctrl_arch_rmid_idx_encode(closid, rmid); struct rmid_entry *entry; lockdep_assert_held(&rdtgroup_mutex); /* * Do not allow the default rmid to be free'd. Comparing by index * allows architectures that ignore the closid parameter to avoid an * unnecessary check. */ if (!resctrl_arch_mon_capable() || idx == resctrl_arch_rmid_idx_encode(RESCTRL_RESERVED_CLOSID, RESCTRL_RESERVED_RMID)) return; entry = __rmid_entry(idx); if (is_llc_occupancy_enabled()) add_rmid_to_limbo(entry); else list_add_tail(&entry->list, &rmid_free_lru); } static struct mbm_state *get_mbm_state(struct rdt_mon_domain *d, u32 closid, u32 rmid, enum resctrl_event_id evtid) { u32 idx = resctrl_arch_rmid_idx_encode(closid, rmid); switch (evtid) { case QOS_L3_MBM_TOTAL_EVENT_ID: return &d->mbm_total[idx]; case QOS_L3_MBM_LOCAL_EVENT_ID: return &d->mbm_local[idx]; default: return NULL; } } static int __mon_event_count(u32 closid, u32 rmid, struct rmid_read *rr) { int cpu = smp_processor_id(); struct rdt_mon_domain *d; struct mbm_state *m; int err, ret; u64 tval = 0; if (rr->first) { resctrl_arch_reset_rmid(rr->r, rr->d, closid, rmid, rr->evtid); m = get_mbm_state(rr->d, closid, rmid, rr->evtid); if (m) memset(m, 0, sizeof(struct mbm_state)); return 0; } if (rr->d) { /* Reading a single domain, must be on a CPU in that domain. */ if (!cpumask_test_cpu(cpu, &rr->d->hdr.cpu_mask)) return -EINVAL; rr->err = resctrl_arch_rmid_read(rr->r, rr->d, closid, rmid, rr->evtid, &tval, rr->arch_mon_ctx); if (rr->err) return rr->err; rr->val += tval; return 0; } /* Summing domains that share a cache, must be on a CPU for that cache. */ if (!cpumask_test_cpu(cpu, &rr->ci->shared_cpu_map)) return -EINVAL; /* * Legacy files must report the sum of an event across all * domains that share the same L3 cache instance. * Report success if a read from any domain succeeds, -EINVAL * (translated to "Unavailable" for user space) if reading from * all domains fail for any reason. */ ret = -EINVAL; list_for_each_entry(d, &rr->r->mon_domains, hdr.list) { if (d->ci->id != rr->ci->id) continue; err = resctrl_arch_rmid_read(rr->r, d, closid, rmid, rr->evtid, &tval, rr->arch_mon_ctx); if (!err) { rr->val += tval; ret = 0; } } if (ret) rr->err = ret; return ret; } /* * mbm_bw_count() - Update bw count from values previously read by * __mon_event_count(). * @closid: The closid used to identify the cached mbm_state. * @rmid: The rmid used to identify the cached mbm_state. * @rr: The struct rmid_read populated by __mon_event_count(). * * Supporting function to calculate the memory bandwidth * and delta bandwidth in MBps. The chunks value previously read by * __mon_event_count() is compared with the chunks value from the previous * invocation. This must be called once per second to maintain values in MBps. */ static void mbm_bw_count(u32 closid, u32 rmid, struct rmid_read *rr) { u32 idx = resctrl_arch_rmid_idx_encode(closid, rmid); struct mbm_state *m = &rr->d->mbm_local[idx]; u64 cur_bw, bytes, cur_bytes; cur_bytes = rr->val; bytes = cur_bytes - m->prev_bw_bytes; m->prev_bw_bytes = cur_bytes; cur_bw = bytes / SZ_1M; m->prev_bw = cur_bw; } /* * This is scheduled by mon_event_read() to read the CQM/MBM counters * on a domain. */ void mon_event_count(void *info) { struct rdtgroup *rdtgrp, *entry; struct rmid_read *rr = info; struct list_head *head; int ret; rdtgrp = rr->rgrp; ret = __mon_event_count(rdtgrp->closid, rdtgrp->mon.rmid, rr); /* * For Ctrl groups read data from child monitor groups and * add them together. Count events which are read successfully. * Discard the rmid_read's reporting errors. */ head = &rdtgrp->mon.crdtgrp_list; if (rdtgrp->type == RDTCTRL_GROUP) { list_for_each_entry(entry, head, mon.crdtgrp_list) { if (__mon_event_count(entry->closid, entry->mon.rmid, rr) == 0) ret = 0; } } /* * __mon_event_count() calls for newly created monitor groups may * report -EINVAL/Unavailable if the monitor hasn't seen any traffic. * Discard error if any of the monitor event reads succeeded. */ if (ret == 0) rr->err = 0; } /* * Feedback loop for MBA software controller (mba_sc) * * mba_sc is a feedback loop where we periodically read MBM counters and * adjust the bandwidth percentage values via the IA32_MBA_THRTL_MSRs so * that: * * current bandwidth(cur_bw) < user specified bandwidth(user_bw) * * This uses the MBM counters to measure the bandwidth and MBA throttle * MSRs to control the bandwidth for a particular rdtgrp. It builds on the * fact that resctrl rdtgroups have both monitoring and control. * * The frequency of the checks is 1s and we just tag along the MBM overflow * timer. Having 1s interval makes the calculation of bandwidth simpler. * * Although MBA's goal is to restrict the bandwidth to a maximum, there may * be a need to increase the bandwidth to avoid unnecessarily restricting * the L2 <-> L3 traffic. * * Since MBA controls the L2 external bandwidth where as MBM measures the * L3 external bandwidth the following sequence could lead to such a * situation. * * Consider an rdtgroup which had high L3 <-> memory traffic in initial * phases -> mba_sc kicks in and reduced bandwidth percentage values -> but * after some time rdtgroup has mostly L2 <-> L3 traffic. * * In this case we may restrict the rdtgroup's L2 <-> L3 traffic as its * throttle MSRs already have low percentage values. To avoid * unnecessarily restricting such rdtgroups, we also increase the bandwidth. */ static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_mon_domain *dom_mbm) { u32 closid, rmid, cur_msr_val, new_msr_val; struct mbm_state *pmbm_data, *cmbm_data; struct rdt_ctrl_domain *dom_mba; struct rdt_resource *r_mba; u32 cur_bw, user_bw, idx; struct list_head *head; struct rdtgroup *entry; if (!is_mbm_local_enabled()) return; r_mba = &rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl; closid = rgrp->closid; rmid = rgrp->mon.rmid; idx = resctrl_arch_rmid_idx_encode(closid, rmid); pmbm_data = &dom_mbm->mbm_local[idx]; dom_mba = get_ctrl_domain_from_cpu(smp_processor_id(), r_mba); if (!dom_mba) { pr_warn_once("Failure to get domain for MBA update\n"); return; } cur_bw = pmbm_data->prev_bw; user_bw = dom_mba->mbps_val[closid]; /* MBA resource doesn't support CDP */ cur_msr_val = resctrl_arch_get_config(r_mba, dom_mba, closid, CDP_NONE); /* * For Ctrl groups read data from child monitor groups. */ head = &rgrp->mon.crdtgrp_list; list_for_each_entry(entry, head, mon.crdtgrp_list) { cmbm_data = &dom_mbm->mbm_local[entry->mon.rmid]; cur_bw += cmbm_data->prev_bw; } /* * Scale up/down the bandwidth linearly for the ctrl group. The * bandwidth step is the bandwidth granularity specified by the * hardware. * Always increase throttling if current bandwidth is above the * target set by user. * But avoid thrashing up and down on every poll by checking * whether a decrease in throttling is likely to push the group * back over target. E.g. if currently throttling to 30% of bandwidth * on a system with 10% granularity steps, check whether moving to * 40% would go past the limit by multiplying current bandwidth by * "(30 + 10) / 30". */ if (cur_msr_val > r_mba->membw.min_bw && user_bw < cur_bw) { new_msr_val = cur_msr_val - r_mba->membw.bw_gran; } else if (cur_msr_val < MAX_MBA_BW && (user_bw > (cur_bw * (cur_msr_val + r_mba->membw.min_bw) / cur_msr_val))) { new_msr_val = cur_msr_val + r_mba->membw.bw_gran; } else { return; } resctrl_arch_update_one(r_mba, dom_mba, closid, CDP_NONE, new_msr_val); } static void mbm_update(struct rdt_resource *r, struct rdt_mon_domain *d, u32 closid, u32 rmid) { struct rmid_read rr = {0}; rr.r = r; rr.d = d; /* * This is protected from concurrent reads from user * as both the user and we hold the global mutex. */ if (is_mbm_total_enabled()) { rr.evtid = QOS_L3_MBM_TOTAL_EVENT_ID; rr.val = 0; rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, rr.evtid); if (IS_ERR(rr.arch_mon_ctx)) { pr_warn_ratelimited("Failed to allocate monitor context: %ld", PTR_ERR(rr.arch_mon_ctx)); return; } __mon_event_count(closid, rmid, &rr); resctrl_arch_mon_ctx_free(rr.r, rr.evtid, rr.arch_mon_ctx); } if (is_mbm_local_enabled()) { rr.evtid = QOS_L3_MBM_LOCAL_EVENT_ID; rr.val = 0; rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, rr.evtid); if (IS_ERR(rr.arch_mon_ctx)) { pr_warn_ratelimited("Failed to allocate monitor context: %ld", PTR_ERR(rr.arch_mon_ctx)); return; } __mon_event_count(closid, rmid, &rr); /* * Call the MBA software controller only for the * control groups and when user has enabled * the software controller explicitly. */ if (is_mba_sc(NULL)) mbm_bw_count(closid, rmid, &rr); resctrl_arch_mon_ctx_free(rr.r, rr.evtid, rr.arch_mon_ctx); } } /* * Handler to scan the limbo list and move the RMIDs * to free list whose occupancy < threshold_occupancy. */ void cqm_handle_limbo(struct work_struct *work) { unsigned long delay = msecs_to_jiffies(CQM_LIMBOCHECK_INTERVAL); struct rdt_mon_domain *d; cpus_read_lock(); mutex_lock(&rdtgroup_mutex); d = container_of(work, struct rdt_mon_domain, cqm_limbo.work); __check_limbo(d, false); if (has_busy_rmid(d)) { d->cqm_work_cpu = cpumask_any_housekeeping(&d->hdr.cpu_mask, RESCTRL_PICK_ANY_CPU); schedule_delayed_work_on(d->cqm_work_cpu, &d->cqm_limbo, delay); } mutex_unlock(&rdtgroup_mutex); cpus_read_unlock(); } /** * cqm_setup_limbo_handler() - Schedule the limbo handler to run for this * domain. * @dom: The domain the limbo handler should run for. * @delay_ms: How far in the future the handler should run. * @exclude_cpu: Which CPU the handler should not run on, * RESCTRL_PICK_ANY_CPU to pick any CPU. */ void cqm_setup_limbo_handler(struct rdt_mon_domain *dom, unsigned long delay_ms, int exclude_cpu) { unsigned long delay = msecs_to_jiffies(delay_ms); int cpu; cpu = cpumask_any_housekeeping(&dom->hdr.cpu_mask, exclude_cpu); dom->cqm_work_cpu = cpu; if (cpu < nr_cpu_ids) schedule_delayed_work_on(cpu, &dom->cqm_limbo, delay); } void mbm_handle_overflow(struct work_struct *work) { unsigned long delay = msecs_to_jiffies(MBM_OVERFLOW_INTERVAL); struct rdtgroup *prgrp, *crgrp; struct rdt_mon_domain *d; struct list_head *head; struct rdt_resource *r; cpus_read_lock(); mutex_lock(&rdtgroup_mutex); /* * If the filesystem has been unmounted this work no longer needs to * run. */ if (!resctrl_mounted || !resctrl_arch_mon_capable()) goto out_unlock; r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl; d = container_of(work, struct rdt_mon_domain, mbm_over.work); list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) { mbm_update(r, d, prgrp->closid, prgrp->mon.rmid); head = &prgrp->mon.crdtgrp_list; list_for_each_entry(crgrp, head, mon.crdtgrp_list) mbm_update(r, d, crgrp->closid, crgrp->mon.rmid); if (is_mba_sc(NULL)) update_mba_bw(prgrp, d); } /* * Re-check for housekeeping CPUs. This allows the overflow handler to * move off a nohz_full CPU quickly. */ d->mbm_work_cpu = cpumask_any_housekeeping(&d->hdr.cpu_mask, RESCTRL_PICK_ANY_CPU); schedule_delayed_work_on(d->mbm_work_cpu, &d->mbm_over, delay); out_unlock: mutex_unlock(&rdtgroup_mutex); cpus_read_unlock(); } /** * mbm_setup_overflow_handler() - Schedule the overflow handler to run for this * domain. * @dom: The domain the overflow handler should run for. * @delay_ms: How far in the future the handler should run. * @exclude_cpu: Which CPU the handler should not run on, * RESCTRL_PICK_ANY_CPU to pick any CPU. */ void mbm_setup_overflow_handler(struct rdt_mon_domain *dom, unsigned long delay_ms, int exclude_cpu) { unsigned long delay = msecs_to_jiffies(delay_ms); int cpu; /* * When a domain comes online there is no guarantee the filesystem is * mounted. If not, there is no need to catch counter overflow. */ if (!resctrl_mounted || !resctrl_arch_mon_capable()) return; cpu = cpumask_any_housekeeping(&dom->hdr.cpu_mask, exclude_cpu); dom->mbm_work_cpu = cpu; if (cpu < nr_cpu_ids) schedule_delayed_work_on(cpu, &dom->mbm_over, delay); } static int dom_data_init(struct rdt_resource *r) { u32 idx_limit = resctrl_arch_system_num_rmid_idx(); u32 num_closid = resctrl_arch_get_num_closid(r); struct rmid_entry *entry = NULL; int err = 0, i; u32 idx; mutex_lock(&rdtgroup_mutex); if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) { u32 *tmp; /* * If the architecture hasn't provided a sanitised value here, * this may result in larger arrays than necessary. Resctrl will * use a smaller system wide value based on the resources in * use. */ tmp = kcalloc(num_closid, sizeof(*tmp), GFP_KERNEL); if (!tmp) { err = -ENOMEM; goto out_unlock; } closid_num_dirty_rmid = tmp; } rmid_ptrs = kcalloc(idx_limit, sizeof(struct rmid_entry), GFP_KERNEL); if (!rmid_ptrs) { if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) { kfree(closid_num_dirty_rmid); closid_num_dirty_rmid = NULL; } err = -ENOMEM; goto out_unlock; } for (i = 0; i < idx_limit; i++) { entry = &rmid_ptrs[i]; INIT_LIST_HEAD(&entry->list); resctrl_arch_rmid_idx_decode(i, &entry->closid, &entry->rmid); list_add_tail(&entry->list, &rmid_free_lru); } /* * RESCTRL_RESERVED_CLOSID and RESCTRL_RESERVED_RMID are special and * are always allocated. These are used for the rdtgroup_default * control group, which will be setup later in rdtgroup_init(). */ idx = resctrl_arch_rmid_idx_encode(RESCTRL_RESERVED_CLOSID, RESCTRL_RESERVED_RMID); entry = __rmid_entry(idx); list_del(&entry->list); out_unlock: mutex_unlock(&rdtgroup_mutex); return err; } static void __exit dom_data_exit(void) { mutex_lock(&rdtgroup_mutex); if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) { kfree(closid_num_dirty_rmid); closid_num_dirty_rmid = NULL; } kfree(rmid_ptrs); rmid_ptrs = NULL; mutex_unlock(&rdtgroup_mutex); } static struct mon_evt llc_occupancy_event = { .name = "llc_occupancy", .evtid = QOS_L3_OCCUP_EVENT_ID, }; static struct mon_evt mbm_total_event = { .name = "mbm_total_bytes", .evtid = QOS_L3_MBM_TOTAL_EVENT_ID, }; static struct mon_evt mbm_local_event = { .name = "mbm_local_bytes", .evtid = QOS_L3_MBM_LOCAL_EVENT_ID, }; /* * Initialize the event list for the resource. * * Note that MBM events are also part of RDT_RESOURCE_L3 resource * because as per the SDM the total and local memory bandwidth * are enumerated as part of L3 monitoring. */ static void l3_mon_evt_init(struct rdt_resource *r) { INIT_LIST_HEAD(&r->evt_list); if (is_llc_occupancy_enabled()) list_add_tail(&llc_occupancy_event.list, &r->evt_list); if (is_mbm_total_enabled()) list_add_tail(&mbm_total_event.list, &r->evt_list); if (is_mbm_local_enabled()) 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); } /* CPU models that support MSR_RMID_SNC_CONFIG */ static const struct x86_cpu_id snc_cpu_ids[] __initconst = { X86_MATCH_VFM(INTEL_ICELAKE_X, 0), X86_MATCH_VFM(INTEL_SAPPHIRERAPIDS_X, 0), X86_MATCH_VFM(INTEL_EMERALDRAPIDS_X, 0), X86_MATCH_VFM(INTEL_GRANITERAPIDS_X, 0), X86_MATCH_VFM(INTEL_ATOM_CRESTMONT_X, 0), {} }; /* * There isn't a simple hardware bit that indicates whether a CPU is running * in Sub-NUMA Cluster (SNC) mode. Infer the state by comparing the * number of CPUs sharing the L3 cache with CPU0 to the number of CPUs in * the same NUMA node as CPU0. * It is not possible to accurately determine SNC state if the system is * booted with a maxcpus=N parameter. That distorts the ratio of SNC nodes * to L3 caches. It will be OK if system is booted with hyperthreading * disabled (since this doesn't affect the ratio). */ static __init int snc_get_config(void) { struct cacheinfo *ci = get_cpu_cacheinfo_level(0, RESCTRL_L3_CACHE); const cpumask_t *node0_cpumask; int cpus_per_node, cpus_per_l3; int ret; if (!x86_match_cpu(snc_cpu_ids) || !ci) return 1; cpus_read_lock(); if (num_online_cpus() != num_present_cpus()) pr_warn("Some CPUs offline, SNC detection may be incorrect\n"); cpus_read_unlock(); node0_cpumask = cpumask_of_node(cpu_to_node(0)); cpus_per_node = cpumask_weight(node0_cpumask); cpus_per_l3 = cpumask_weight(&ci->shared_cpu_map); if (!cpus_per_node || !cpus_per_l3) return 1; ret = cpus_per_l3 / cpus_per_node; /* sanity check: Only valid results are 1, 2, 3, 4 */ switch (ret) { case 1: break; case 2 ... 4: pr_info("Sub-NUMA Cluster mode detected with %d nodes per L3 cache\n", ret); rdt_resources_all[RDT_RESOURCE_L3].r_resctrl.mon_scope = RESCTRL_L3_NODE; break; default: pr_warn("Ignore improbable SNC node count %d\n", ret); ret = 1; break; } return ret; } int __init rdt_get_mon_l3_config(struct rdt_resource *r) { unsigned int mbm_offset = boot_cpu_data.x86_cache_mbm_width_offset; struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r); unsigned int threshold; int ret; snc_nodes_per_l3_cache = snc_get_config(); resctrl_rmid_realloc_limit = boot_cpu_data.x86_cache_size * 1024; 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) hw_res->mbm_width += mbm_offset; else if (mbm_offset > MBM_CNTR_WIDTH_OFFSET_MAX) pr_warn("Ignoring impossible MBM counter offset\n"); /* * A reasonable upper limit on the max threshold is the number * of lines tagged per RMID if all RMIDs have the same number of * lines tagged in the LLC. * * For a 35MB LLC and 56 RMIDs, this is ~1.8% of the LLC. */ threshold = resctrl_rmid_realloc_limit / r->num_rmid; /* * Because num_rmid may not be a power of two, round the value * to the nearest multiple of hw_res->mon_scale so it matches a * value the hardware will measure. mon_scale may not be a power of 2. */ resctrl_rmid_realloc_threshold = resctrl_arch_round_mon_val(threshold); ret = dom_data_init(r); if (ret) return ret; if (rdt_cpu_has(X86_FEATURE_BMEC)) { u32 eax, ebx, ecx, edx; /* Detect list of bandwidth sources that can be tracked */ cpuid_count(0x80000020, 3, &eax, &ebx, &ecx, &edx); hw_res->mbm_cfg_mask = ecx & MAX_EVT_CONFIG_BITS; if (rdt_cpu_has(X86_FEATURE_CQM_MBM_TOTAL)) { mbm_total_event.configurable = true; mbm_config_rftype_init("mbm_total_bytes_config"); } if (rdt_cpu_has(X86_FEATURE_CQM_MBM_LOCAL)) { mbm_local_event.configurable = true; mbm_config_rftype_init("mbm_local_bytes_config"); } } l3_mon_evt_init(r); r->mon_capable = true; return 0; } void __exit rdt_put_mon_l3_config(void) { dom_data_exit(); } void __init intel_rdt_mbm_apply_quirk(void) { int cf_index; cf_index = (boot_cpu_data.x86_cache_max_rmid + 1) / 8 - 1; if (cf_index >= ARRAY_SIZE(mbm_cf_table)) { pr_info("No MBM correction factor available\n"); return; } mbm_cf_rmidthreshold = mbm_cf_table[cf_index].rmidthreshold; mbm_cf = mbm_cf_table[cf_index].cf; }
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with Cregit http://github.com/cregit/cregit
Version 2.0-RC1