// 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. */ #include <linux/module.h>#include <linux/slab.h>#include <asm/cpu_device_id.h>#include "internal.h" struct rmid_entry { 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); /** * @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 > intel_cqm_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 at which we will consider an * RMID available for re-allocation. */unsigned int resctrl_cqm_threshold; static inline struct rmid_entry *__rmid_entry(u32 rmid){ struct rmid_entry *entry; entry = &rmid_ptrs[rmid]; WARN_ON(entry->rmid != rmid); return entry;} static u64 __rmid_read(u32 rmid, u32 eventid){ u64 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, rmid); rdmsrl(MSR_IA32_QM_CTR, val); return val;} static bool rmid_dirty(struct rmid_entry *entry){ u64 val = __rmid_read(entry->rmid, QOS_L3_OCCUP_EVENT_ID); return val >= resctrl_cqm_threshold;} /* * 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_domain *d, bool force_free){ struct rmid_entry *entry; struct rdt_resource *r; u32 crmid = 1, nrmid; r = &rdt_resources_all[RDT_RESOURCE_L3]; /* * 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 (;;) { nrmid = find_next_bit(d->rmid_busy_llc, r->num_rmid, crmid); if (nrmid >= r->num_rmid) break; entry = __rmid_entry(nrmid); if (force_free || !rmid_dirty(entry)) { clear_bit(entry->rmid, d->rmid_busy_llc); if (!--entry->busy) { rmid_limbo_count--; list_add_tail(&entry->list, &rmid_free_lru); } } crmid = nrmid + 1; }} bool has_busy_rmid(struct rdt_resource *r, struct rdt_domain *d){ return find_first_bit(d->rmid_busy_llc, r->num_rmid) != r->num_rmid;} /* * As of now the RMIDs allocation is global. * However we keep track of which packages the RMIDs * are used to optimize the limbo list management. */int alloc_rmid(void){ struct rmid_entry *entry; lockdep_assert_held(&rdtgroup_mutex); if (list_empty(&rmid_free_lru)) return rmid_limbo_count ? -EBUSY : -ENOSPC; entry = list_first_entry(&rmid_free_lru, struct rmid_entry, list); list_del(&entry->list); return entry->rmid;} static void add_rmid_to_limbo(struct rmid_entry *entry){ struct rdt_resource *r; struct rdt_domain *d; int cpu; u64 val; r = &rdt_resources_all[RDT_RESOURCE_L3]; entry->busy = 0; cpu = get_cpu(); list_for_each_entry(d, &r->domains, list) { if (cpumask_test_cpu(cpu, &d->cpu_mask)) { val = __rmid_read(entry->rmid, QOS_L3_OCCUP_EVENT_ID); if (val <= resctrl_cqm_threshold) continue; } /* * For the first limbo RMID in the domain, * setup up the limbo worker. */ if (!has_busy_rmid(r, d)) cqm_setup_limbo_handler(d, CQM_LIMBOCHECK_INTERVAL); set_bit(entry->rmid, d->rmid_busy_llc); entry->busy++; } put_cpu(); if (entry->busy) rmid_limbo_count++; else list_add_tail(&entry->list, &rmid_free_lru);} void free_rmid(u32 rmid){ struct rmid_entry *entry; if (!rmid) return; lockdep_assert_held(&rdtgroup_mutex); entry = __rmid_entry(rmid); if (is_llc_occupancy_enabled()) add_rmid_to_limbo(entry); else list_add_tail(&entry->list, &rmid_free_lru);} static u64 mbm_overflow_count(u64 prev_msr, u64 cur_msr){ u64 shift = 64 - MBM_CNTR_WIDTH, chunks; chunks = (cur_msr << shift) - (prev_msr << shift); return chunks >>= shift;} static int __mon_event_count(u32 rmid, struct rmid_read *rr){ struct mbm_state *m; u64 chunks, tval; tval = __rmid_read(rmid, rr->evtid); if (tval & (RMID_VAL_ERROR | RMID_VAL_UNAVAIL)) { rr->val = tval; return -EINVAL; } switch (rr->evtid) { case QOS_L3_OCCUP_EVENT_ID: rr->val += tval; return 0; case QOS_L3_MBM_TOTAL_EVENT_ID: m = &rr->d->mbm_total[rmid]; break; case QOS_L3_MBM_LOCAL_EVENT_ID: m = &rr->d->mbm_local[rmid]; break; default: /* * Code would never reach here because * an invalid event id would fail the __rmid_read. */ return -EINVAL; } if (rr->first) { memset(m, 0, sizeof(struct mbm_state)); m->prev_bw_msr = m->prev_msr = tval; return 0; } chunks = mbm_overflow_count(m->prev_msr, tval); m->chunks += chunks; m->prev_msr = tval; rr->val += m->chunks; return 0;} /* * Supporting function to calculate the memory bandwidth * and delta bandwidth in MBps. */static void mbm_bw_count(u32 rmid, struct rmid_read *rr){ struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3]; struct mbm_state *m = &rr->d->mbm_local[rmid]; u64 tval, cur_bw, chunks; tval = __rmid_read(rmid, rr->evtid); if (tval & (RMID_VAL_ERROR | RMID_VAL_UNAVAIL)) return; chunks = mbm_overflow_count(m->prev_bw_msr, tval); m->chunks_bw += chunks; m->chunks = m->chunks_bw; cur_bw = (chunks * r->mon_scale) >> 20; if (m->delta_comp) m->delta_bw = abs(cur_bw - m->prev_bw); m->delta_comp = false; m->prev_bw = cur_bw; m->prev_bw_msr = tval;} /* * This is called via IPI 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; rdtgrp = rr->rgrp; if (__mon_event_count(rdtgrp->mon.rmid, rr)) return; /* * For Ctrl groups read data from child monitor groups. */ head = &rdtgrp->mon.crdtgrp_list; if (rdtgrp->type == RDTCTRL_GROUP) { list_for_each_entry(entry, head, mon.crdtgrp_list) { if (__mon_event_count(entry->mon.rmid, rr)) return; } }} /* * 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 bandwdith(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 uncecessarily 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_domain *dom_mbm){ u32 closid, rmid, cur_msr, cur_msr_val, new_msr_val; struct mbm_state *pmbm_data, *cmbm_data; u32 cur_bw, delta_bw, user_bw; struct rdt_resource *r_mba; struct rdt_domain *dom_mba; struct list_head *head; struct rdtgroup *entry; if (!is_mbm_local_enabled()) return; r_mba = &rdt_resources_all[RDT_RESOURCE_MBA]; closid = rgrp->closid; rmid = rgrp->mon.rmid; pmbm_data = &dom_mbm->mbm_local[rmid]; dom_mba = get_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]; delta_bw = pmbm_data->delta_bw; cur_msr_val = dom_mba->ctrl_val[closid]; /* * 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; delta_bw += cmbm_data->delta_bw; } /* * Scale up/down the bandwidth linearly for the ctrl group. The * bandwidth step is the bandwidth granularity specified by the * hardware. * * The delta_bw is used when increasing the bandwidth so that we * dont alternately increase and decrease the control values * continuously. * * For ex: consider cur_bw = 90MBps, user_bw = 100MBps and if * bandwidth step is 20MBps(> user_bw - cur_bw), we would keep * switching between 90 and 110 continuously if we only check * cur_bw < user_bw. */ 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 + delta_bw))) { new_msr_val = cur_msr_val + r_mba->membw.bw_gran; } else { return; } cur_msr = r_mba->msr_base + closid; wrmsrl(cur_msr, delay_bw_map(new_msr_val, r_mba)); dom_mba->ctrl_val[closid] = new_msr_val; /* * Delta values are updated dynamically package wise for each * rdtgrp everytime the throttle MSR changes value. * * This is because (1)the increase in bandwidth is not perfectly * linear and only "approximately" linear even when the hardware * says it is linear.(2)Also since MBA is a core specific * mechanism, the delta values vary based on number of cores used * by the rdtgrp. */ pmbm_data->delta_comp = true; list_for_each_entry(entry, head, mon.crdtgrp_list) { cmbm_data = &dom_mbm->mbm_local[entry->mon.rmid]; cmbm_data->delta_comp = true; }} static void mbm_update(struct rdt_domain *d, int rmid){ struct rmid_read rr; rr.first = false; 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; __mon_event_count(rmid, &rr); } if (is_mbm_local_enabled()) { rr.evtid = QOS_L3_MBM_LOCAL_EVENT_ID; /* * Call the MBA software controller only for the * control groups and when user has enabled * the software controller explicitly. */ if (!is_mba_sc(NULL)) __mon_event_count(rmid, &rr); else mbm_bw_count(rmid, &rr); }} /* * 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); int cpu = smp_processor_id(); struct rdt_resource *r; struct rdt_domain *d; mutex_lock(&rdtgroup_mutex); r = &rdt_resources_all[RDT_RESOURCE_L3]; d = get_domain_from_cpu(cpu, r); if (!d) { pr_warn_once("Failure to get domain for limbo worker\n"); goto out_unlock; } __check_limbo(d, false); if (has_busy_rmid(r, d)) schedule_delayed_work_on(cpu, &d->cqm_limbo, delay); out_unlock: mutex_unlock(&rdtgroup_mutex);} void cqm_setup_limbo_handler(struct rdt_domain *dom, unsigned long delay_ms){ unsigned long delay = msecs_to_jiffies(delay_ms); int cpu; Lines 1–500 of 645. 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// 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. */ #include <linux/module.h> #include <linux/slab.h> #include <asm/cpu_device_id.h> #include "internal.h" struct rmid_entry { 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); /** * @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 > intel_cqm_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 at which we will consider an * RMID available for re-allocation. */ unsigned int resctrl_cqm_threshold; static inline struct rmid_entry *__rmid_entry(u32 rmid) { struct rmid_entry *entry; entry = &rmid_ptrs[rmid]; WARN_ON(entry->rmid != rmid); return entry; } static u64 __rmid_read(u32 rmid, u32 eventid) { u64 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, rmid); rdmsrl(MSR_IA32_QM_CTR, val); return val; } static bool rmid_dirty(struct rmid_entry *entry) { u64 val = __rmid_read(entry->rmid, QOS_L3_OCCUP_EVENT_ID); return val >= resctrl_cqm_threshold; } /* * 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_domain *d, bool force_free) { struct rmid_entry *entry; struct rdt_resource *r; u32 crmid = 1, nrmid; r = &rdt_resources_all[RDT_RESOURCE_L3]; /* * 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 (;;) { nrmid = find_next_bit(d->rmid_busy_llc, r->num_rmid, crmid); if (nrmid >= r->num_rmid) break; entry = __rmid_entry(nrmid); if (force_free || !rmid_dirty(entry)) { clear_bit(entry->rmid, d->rmid_busy_llc); if (!--entry->busy) { rmid_limbo_count--; list_add_tail(&entry->list, &rmid_free_lru); } } crmid = nrmid + 1; } } bool has_busy_rmid(struct rdt_resource *r, struct rdt_domain *d) { return find_first_bit(d->rmid_busy_llc, r->num_rmid) != r->num_rmid; } /* * As of now the RMIDs allocation is global. * However we keep track of which packages the RMIDs * are used to optimize the limbo list management. */ int alloc_rmid(void) { struct rmid_entry *entry; lockdep_assert_held(&rdtgroup_mutex); if (list_empty(&rmid_free_lru)) return rmid_limbo_count ? -EBUSY : -ENOSPC; entry = list_first_entry(&rmid_free_lru, struct rmid_entry, list); list_del(&entry->list); return entry->rmid; } static void add_rmid_to_limbo(struct rmid_entry *entry) { struct rdt_resource *r; struct rdt_domain *d; int cpu; u64 val; r = &rdt_resources_all[RDT_RESOURCE_L3]; entry->busy = 0; cpu = get_cpu(); list_for_each_entry(d, &r->domains, list) { if (cpumask_test_cpu(cpu, &d->cpu_mask)) { val = __rmid_read(entry->rmid, QOS_L3_OCCUP_EVENT_ID); if (val <= resctrl_cqm_threshold) continue; } /* * For the first limbo RMID in the domain, * setup up the limbo worker. */ if (!has_busy_rmid(r, d)) cqm_setup_limbo_handler(d, CQM_LIMBOCHECK_INTERVAL); set_bit(entry->rmid, d->rmid_busy_llc); entry->busy++; } put_cpu(); if (entry->busy) rmid_limbo_count++; else list_add_tail(&entry->list, &rmid_free_lru); } void free_rmid(u32 rmid) { struct rmid_entry *entry; if (!rmid) return; lockdep_assert_held(&rdtgroup_mutex); entry = __rmid_entry(rmid); if (is_llc_occupancy_enabled()) add_rmid_to_limbo(entry); else list_add_tail(&entry->list, &rmid_free_lru); } static u64 mbm_overflow_count(u64 prev_msr, u64 cur_msr) { u64 shift = 64 - MBM_CNTR_WIDTH, chunks; chunks = (cur_msr << shift) - (prev_msr << shift); return chunks >>= shift; } static int __mon_event_count(u32 rmid, struct rmid_read *rr) { struct mbm_state *m; u64 chunks, tval; tval = __rmid_read(rmid, rr->evtid); if (tval & (RMID_VAL_ERROR | RMID_VAL_UNAVAIL)) { rr->val = tval; return -EINVAL; } switch (rr->evtid) { case QOS_L3_OCCUP_EVENT_ID: rr->val += tval; return 0; case QOS_L3_MBM_TOTAL_EVENT_ID: m = &rr->d->mbm_total[rmid]; break; case QOS_L3_MBM_LOCAL_EVENT_ID: m = &rr->d->mbm_local[rmid]; break; default: /* * Code would never reach here because * an invalid event id would fail the __rmid_read. */ return -EINVAL; } if (rr->first) { memset(m, 0, sizeof(struct mbm_state)); m->prev_bw_msr = m->prev_msr = tval; return 0; } chunks = mbm_overflow_count(m->prev_msr, tval); m->chunks += chunks; m->prev_msr = tval; rr->val += m->chunks; return 0; } /* * Supporting function to calculate the memory bandwidth * and delta bandwidth in MBps. */ static void mbm_bw_count(u32 rmid, struct rmid_read *rr) { struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3]; struct mbm_state *m = &rr->d->mbm_local[rmid]; u64 tval, cur_bw, chunks; tval = __rmid_read(rmid, rr->evtid); if (tval & (RMID_VAL_ERROR | RMID_VAL_UNAVAIL)) return; chunks = mbm_overflow_count(m->prev_bw_msr, tval); m->chunks_bw += chunks; m->chunks = m->chunks_bw; cur_bw = (chunks * r->mon_scale) >> 20; if (m->delta_comp) m->delta_bw = abs(cur_bw - m->prev_bw); m->delta_comp = false; m->prev_bw = cur_bw; m->prev_bw_msr = tval; } /* * This is called via IPI 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; rdtgrp = rr->rgrp; if (__mon_event_count(rdtgrp->mon.rmid, rr)) return; /* * For Ctrl groups read data from child monitor groups. */ head = &rdtgrp->mon.crdtgrp_list; if (rdtgrp->type == RDTCTRL_GROUP) { list_for_each_entry(entry, head, mon.crdtgrp_list) { if (__mon_event_count(entry->mon.rmid, rr)) return; } } } /* * 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 bandwdith(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 uncecessarily 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_domain *dom_mbm) { u32 closid, rmid, cur_msr, cur_msr_val, new_msr_val; struct mbm_state *pmbm_data, *cmbm_data; u32 cur_bw, delta_bw, user_bw; struct rdt_resource *r_mba; struct rdt_domain *dom_mba; struct list_head *head; struct rdtgroup *entry; if (!is_mbm_local_enabled()) return; r_mba = &rdt_resources_all[RDT_RESOURCE_MBA]; closid = rgrp->closid; rmid = rgrp->mon.rmid; pmbm_data = &dom_mbm->mbm_local[rmid]; dom_mba = get_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]; delta_bw = pmbm_data->delta_bw; cur_msr_val = dom_mba->ctrl_val[closid]; /* * 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; delta_bw += cmbm_data->delta_bw; } /* * Scale up/down the bandwidth linearly for the ctrl group. The * bandwidth step is the bandwidth granularity specified by the * hardware. * * The delta_bw is used when increasing the bandwidth so that we * dont alternately increase and decrease the control values * continuously. * * For ex: consider cur_bw = 90MBps, user_bw = 100MBps and if * bandwidth step is 20MBps(> user_bw - cur_bw), we would keep * switching between 90 and 110 continuously if we only check * cur_bw < user_bw. */ 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 + delta_bw))) { new_msr_val = cur_msr_val + r_mba->membw.bw_gran; } else { return; } cur_msr = r_mba->msr_base + closid; wrmsrl(cur_msr, delay_bw_map(new_msr_val, r_mba)); dom_mba->ctrl_val[closid] = new_msr_val; /* * Delta values are updated dynamically package wise for each * rdtgrp everytime the throttle MSR changes value. * * This is because (1)the increase in bandwidth is not perfectly * linear and only "approximately" linear even when the hardware * says it is linear.(2)Also since MBA is a core specific * mechanism, the delta values vary based on number of cores used * by the rdtgrp. */ pmbm_data->delta_comp = true; list_for_each_entry(entry, head, mon.crdtgrp_list) { cmbm_data = &dom_mbm->mbm_local[entry->mon.rmid]; cmbm_data->delta_comp = true; } } static void mbm_update(struct rdt_domain *d, int rmid) { struct rmid_read rr; rr.first = false; 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; __mon_event_count(rmid, &rr); } if (is_mbm_local_enabled()) { rr.evtid = QOS_L3_MBM_LOCAL_EVENT_ID; /* * Call the MBA software controller only for the * control groups and when user has enabled * the software controller explicitly. */ if (!is_mba_sc(NULL)) __mon_event_count(rmid, &rr); else mbm_bw_count(rmid, &rr); } } /* * 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); int cpu = smp_processor_id(); struct rdt_resource *r; struct rdt_domain *d; mutex_lock(&rdtgroup_mutex); r = &rdt_resources_all[RDT_RESOURCE_L3]; d = get_domain_from_cpu(cpu, r); if (!d) { pr_warn_once("Failure to get domain for limbo worker\n"); goto out_unlock; } __check_limbo(d, false); if (has_busy_rmid(r, d)) schedule_delayed_work_on(cpu, &d->cqm_limbo, delay); out_unlock: mutex_unlock(&rdtgroup_mutex); } void cqm_setup_limbo_handler(struct rdt_domain *dom, unsigned long delay_ms) { unsigned long delay = msecs_to_jiffies(delay_ms); int cpu;