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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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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. */
#define pr_fmt(fmt) "resctrl: " fmt
#include <linux/cpu.h>#include <linux/resctrl.h>#include <linux/sizes.h>#include <linux/slab.h>
#include "internal.h"
#define CREATE_TRACE_POINTS
#include "monitor_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;
/* * 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;
/* * 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;}
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_l3_mon_domain *d, bool force_free){ struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3); u32 idx_limit = resctrl_arch_system_num_rmid_idx(); struct rmid_entry *entry; bool rmid_dirty = true; u32 idx, cur_idx = 1; void *arch_mon_ctx; void *arch_priv; u64 val = 0;
arch_priv = mon_event_all[QOS_L3_OCCUP_EVENT_ID].arch_priv; 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 (!force_free) { if (resctrl_arch_rmid_read(r, &d->hdr, entry->closid, entry->rmid, QOS_L3_OCCUP_EVENT_ID, arch_priv, &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_l3_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. * * Return: Free CLOSID on success, < 0 on failure. */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 = resctrl_arch_get_resource(RDT_RESOURCE_L3); struct rdt_l3_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 (resctrl_is_mon_event_enabled(QOS_L3_OCCUP_EVENT_ID)) add_rmid_to_limbo(entry); else list_add_tail(&entry->list, &rmid_free_lru);}
static struct mbm_state *get_mbm_state(struct rdt_l3_mon_domain *d, u32 closid, u32 rmid, enum resctrl_event_id evtid){ u32 idx = resctrl_arch_rmid_idx_encode(closid, rmid); struct mbm_state *state;
if (!resctrl_is_mbm_event(evtid)) return NULL;
state = d->mbm_states[MBM_STATE_IDX(evtid)];
return state ? &state[idx] : NULL;}
/* * mbm_cntr_get() - Return the counter ID for the matching @evtid and @rdtgrp. * * Return: * Valid counter ID on success, or -ENOENT on failure. */static int mbm_cntr_get(struct rdt_resource *r, struct rdt_l3_mon_domain *d, struct rdtgroup *rdtgrp, enum resctrl_event_id evtid){ int cntr_id;
if (!r->mon.mbm_cntr_assignable) return -ENOENT;
if (!resctrl_is_mbm_event(evtid)) return -ENOENT;
for (cntr_id = 0; cntr_id < r->mon.num_mbm_cntrs; cntr_id++) { if (d->cntr_cfg[cntr_id].rdtgrp == rdtgrp && d->cntr_cfg[cntr_id].evtid == evtid) return cntr_id; }
return -ENOENT;}
/* * mbm_cntr_alloc() - Initialize and return a new counter ID in the domain @d. * Caller must ensure that the specified event is not assigned already. * * Return: * Valid counter ID on success, or -ENOSPC on failure. */static int mbm_cntr_alloc(struct rdt_resource *r, struct rdt_l3_mon_domain *d, struct rdtgroup *rdtgrp, enum resctrl_event_id evtid){ int cntr_id;
for (cntr_id = 0; cntr_id < r->mon.num_mbm_cntrs; cntr_id++) { if (!d->cntr_cfg[cntr_id].rdtgrp) { d->cntr_cfg[cntr_id].rdtgrp = rdtgrp; d->cntr_cfg[cntr_id].evtid = evtid; return cntr_id; } }
return -ENOSPC;}
/* * mbm_cntr_free() - Clear the counter ID configuration details in the domain @d. */static void mbm_cntr_free(struct rdt_l3_mon_domain *d, int cntr_id){ memset(&d->cntr_cfg[cntr_id], 0, sizeof(*d->cntr_cfg));}
static int __l3_mon_event_count(struct rdtgroup *rdtgrp, struct rmid_read *rr){ int cpu = smp_processor_id(); u32 closid = rdtgrp->closid; u32 rmid = rdtgrp->mon.rmid; struct rdt_l3_mon_domain *d; int cntr_id = -ENOENT; struct mbm_state *m; u64 tval = 0;
if (!domain_header_is_valid(rr->hdr, RESCTRL_MON_DOMAIN, RDT_RESOURCE_L3)) { rr->err = -EIO; return -EINVAL; } d = container_of(rr->hdr, struct rdt_l3_mon_domain, hdr);
if (rr->is_mbm_cntr) { cntr_id = mbm_cntr_get(rr->r, d, rdtgrp, rr->evt->evtid); if (cntr_id < 0) { rr->err = -ENOENT; return -EINVAL; } }
if (rr->first) { if (rr->is_mbm_cntr) resctrl_arch_reset_cntr(rr->r, d, closid, rmid, cntr_id, rr->evt->evtid); else resctrl_arch_reset_rmid(rr->r, d, closid, rmid, rr->evt->evtid); m = get_mbm_state(d, closid, rmid, rr->evt->evtid); if (m) memset(m, 0, sizeof(struct mbm_state)); return 0; }
/* Reading a single domain, must be on a CPU in that domain. */ if (!cpumask_test_cpu(cpu, &d->hdr.cpu_mask)) return -EINVAL; if (rr->is_mbm_cntr) rr->err = resctrl_arch_cntr_read(rr->r, d, closid, rmid, cntr_id, rr->evt->evtid, &tval); else rr->err = resctrl_arch_rmid_read(rr->r, rr->hdr, closid, rmid, rr->evt->evtid, rr->evt->arch_priv, &tval, rr->arch_mon_ctx); if (rr->err) return rr->err;
rr->val += tval;
return 0;}
static int __l3_mon_event_count_sum(struct rdtgroup *rdtgrp, struct rmid_read *rr){ int cpu = smp_processor_id(); u32 closid = rdtgrp->closid; u32 rmid = rdtgrp->mon.rmid; struct rdt_l3_mon_domain *d; u64 tval = 0; int err, ret;
/* * Summing across domains is only done for systems that implement * Sub-NUMA Cluster. There is no overlap with systems that support * assignable counters. */ if (rr->is_mbm_cntr) { pr_warn_once("Summing domains using assignable counters is not supported\n"); rr->err = -EINVAL; return -EINVAL; }
/* 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->hdr, closid, rmid, rr->evt->evtid, rr->evt->arch_priv, &tval, rr->arch_mon_ctx); if (!err) { rr->val += tval; ret = 0; } }
if (ret) rr->err = ret;
return ret;}
static int __mon_event_count(struct rdtgroup *rdtgrp, struct rmid_read *rr){ switch (rr->r->rid) { case RDT_RESOURCE_L3: WARN_ON_ONCE(rr->evt->any_cpu); if (rr->hdr) return __l3_mon_event_count(rdtgrp, rr); else return __l3_mon_event_count_sum(rdtgrp, rr); case RDT_RESOURCE_PERF_PKG: { u64 tval = 0;
rr->err = resctrl_arch_rmid_read(rr->r, rr->hdr, rdtgrp->closid, rdtgrp->mon.rmid, rr->evt->evtid, rr->evt->arch_priv, &tval, rr->arch_mon_ctx); if (rr->err) return rr->err;
rr->val += tval;
return 0; } default: rr->err = -EINVAL; return -EINVAL; }}
/* * mbm_bw_count() - Update bw count from values previously read by * __mon_event_count(). * @rdtgrp: resctrl group associated with the CLOSID and RMID 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(struct rdtgroup *rdtgrp, struct rmid_read *rr){ u64 cur_bw, bytes, cur_bytes; u32 closid = rdtgrp->closid; u32 rmid = rdtgrp->mon.rmid; struct rdt_l3_mon_domain *d; struct mbm_state *m;
if (!domain_header_is_valid(rr->hdr, RESCTRL_MON_DOMAIN, RDT_RESOURCE_L3)) return; d = container_of(rr->hdr, struct rdt_l3_mon_domain, hdr); m = get_mbm_state(d, closid, rmid, rr->evt->evtid); if (WARN_ON_ONCE(!m)) return;
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, 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, 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;}
static struct rdt_ctrl_domain *get_ctrl_domain_from_cpu(int cpu, struct rdt_resource *r){ struct rdt_ctrl_domain *d;
lockdep_assert_cpus_held();
list_for_each_entry(d, &r->ctrl_domains, hdr.list) { /* Find the domain that contains this CPU */ if (cpumask_test_cpu(cpu, &d->hdr.cpu_mask)) return d; }
return NULL;}
/* * 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_l3_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; enum resctrl_event_id evt_id; struct rdt_resource *r_mba; struct list_head *head; struct rdtgroup *entry; u32 cur_bw, user_bw;
r_mba = resctrl_arch_get_resource(RDT_RESOURCE_MBA); evt_id = rgrp->mba_mbps_event;
closid = rgrp->closid; rmid = rgrp->mon.rmid; pmbm_data = get_mbm_state(dom_mbm, closid, rmid, evt_id); if (WARN_ON_ONCE(!pmbm_data)) return;
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 = get_mbm_state(dom_mbm, entry->closid, entry->mon.rmid, evt_id); if (WARN_ON_ONCE(!cmbm_data)) return; 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_one_event(struct rdt_resource *r, struct rdt_l3_mon_domain *d, struct rdtgroup *rdtgrp, enum resctrl_event_id evtid){ struct rmid_read rr = {0};
rr.r = r; rr.hdr = &d->hdr; rr.evt = &mon_event_all[evtid]; if (resctrl_arch_mbm_cntr_assign_enabled(r)) { rr.is_mbm_cntr = true; } else { rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, 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(rdtgrp, &rr);
/* * If the software controller is enabled, compute the * bandwidth for this event id. */ if (is_mba_sc(NULL)) mbm_bw_count(rdtgrp, &rr);
if (rr.arch_mon_ctx) resctrl_arch_mon_ctx_free(rr.r, evtid, rr.arch_mon_ctx);}
static void mbm_update(struct rdt_resource *r, struct rdt_l3_mon_domain *d, struct rdtgroup *rdtgrp){ /* * This is protected from concurrent reads from user as both * the user and overflow handler hold the global mutex. */ if (resctrl_is_mon_event_enabled(QOS_L3_MBM_TOTAL_EVENT_ID)) mbm_update_one_event(r, d, rdtgrp, QOS_L3_MBM_TOTAL_EVENT_ID);
if (resctrl_is_mon_event_enabled(QOS_L3_MBM_LOCAL_EVENT_ID)) mbm_update_one_event(r, d, rdtgrp, QOS_L3_MBM_LOCAL_EVENT_ID);}
/* * 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_l3_mon_domain *d;
cpus_read_lock(); mutex_lock(&rdtgroup_mutex);
d = container_of(work, struct rdt_l3_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_l3_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_l3_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 = resctrl_arch_get_resource(RDT_RESOURCE_L3); d = container_of(work, struct rdt_l3_mon_domain, mbm_over.work);
list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) { mbm_update(r, d, prgrp);
head = &prgrp->mon.crdtgrp_list; list_for_each_entry(crgrp, head, mon.crdtgrp_list) mbm_update(r, d, crgrp);
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_l3_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);}
int setup_rmid_lru_list(void){ struct rmid_entry *entry = NULL; u32 idx_limit; u32 idx; int i;
if (!resctrl_arch_mon_capable()) return 0;
/* * Called on every mount, but the number of RMIDs cannot change * after the first mount, so keep using the same set of rmid_ptrs[] * until resctrl_exit(). Note that the limbo handler continues to * access rmid_ptrs[] after resctrl is unmounted. */ if (rmid_ptrs) return 0;
idx_limit = resctrl_arch_system_num_rmid_idx(); rmid_ptrs = kzalloc_objs(struct rmid_entry, idx_limit); if (!rmid_ptrs) return -ENOMEM;
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 was setup earlier in rdtgroup_setup_default(). */ idx = resctrl_arch_rmid_idx_encode(RESCTRL_RESERVED_CLOSID, RESCTRL_RESERVED_RMID); entry = __rmid_entry(idx); list_del(&entry->list);
return 0;}
void free_rmid_lru_list(void){ if (!resctrl_arch_mon_capable()) return;
mutex_lock(&rdtgroup_mutex); kfree(rmid_ptrs); rmid_ptrs = NULL; mutex_unlock(&rdtgroup_mutex);}
#define MON_EVENT(_eventid, _name, _res, _fp) \ [_eventid] = { \ .name = _name, \ .evtid = _eventid, \ .rid = _res, \ .is_floating_point = _fp, \}
/* * All available events. Architecture code marks the ones that * are supported by a system using resctrl_enable_mon_event() * to set .enabled. */struct mon_evt mon_event_all[QOS_NUM_EVENTS] = { MON_EVENT(QOS_L3_OCCUP_EVENT_ID, "llc_occupancy", RDT_RESOURCE_L3, false), MON_EVENT(QOS_L3_MBM_TOTAL_EVENT_ID, "mbm_total_bytes", RDT_RESOURCE_L3, false), MON_EVENT(QOS_L3_MBM_LOCAL_EVENT_ID, "mbm_local_bytes", RDT_RESOURCE_L3, false), MON_EVENT(PMT_EVENT_ENERGY, "core_energy", RDT_RESOURCE_PERF_PKG, true), MON_EVENT(PMT_EVENT_ACTIVITY, "activity", RDT_RESOURCE_PERF_PKG, true), MON_EVENT(PMT_EVENT_STALLS_LLC_HIT, "stalls_llc_hit", RDT_RESOURCE_PERF_PKG, false), MON_EVENT(PMT_EVENT_C1_RES, "c1_res", RDT_RESOURCE_PERF_PKG, false), MON_EVENT(PMT_EVENT_UNHALTED_CORE_CYCLES, "unhalted_core_cycles", RDT_RESOURCE_PERF_PKG, false), MON_EVENT(PMT_EVENT_STALLS_LLC_MISS, "stalls_llc_miss", RDT_RESOURCE_PERF_PKG, false), MON_EVENT(PMT_EVENT_AUTO_C6_RES, "c6_res", RDT_RESOURCE_PERF_PKG, false), MON_EVENT(PMT_EVENT_UNHALTED_REF_CYCLES, "unhalted_ref_cycles", RDT_RESOURCE_PERF_PKG, false), MON_EVENT(PMT_EVENT_UOPS_RETIRED, "uops_retired", RDT_RESOURCE_PERF_PKG, false),};
bool resctrl_enable_mon_event(enum resctrl_event_id eventid, bool any_cpu, unsigned int binary_bits, void *arch_priv){ if (WARN_ON_ONCE(eventid < QOS_FIRST_EVENT || eventid >= QOS_NUM_EVENTS || binary_bits > MAX_BINARY_BITS)) return false; if (mon_event_all[eventid].enabled) { pr_warn("Duplicate enable for event %d\n", eventid); return false; } if (binary_bits && !mon_event_all[eventid].is_floating_point) { pr_warn("Event %d may not be floating point\n", eventid); return false; }
mon_event_all[eventid].any_cpu = any_cpu; mon_event_all[eventid].binary_bits = binary_bits; mon_event_all[eventid].arch_priv = arch_priv; mon_event_all[eventid].enabled = true;
return true;}
bool resctrl_is_mon_event_enabled(enum resctrl_event_id eventid){ return eventid >= QOS_FIRST_EVENT && eventid < QOS_NUM_EVENTS && mon_event_all[eventid].enabled;}
u32 resctrl_get_mon_evt_cfg(enum resctrl_event_id evtid){ return mon_event_all[evtid].evt_cfg;}
/** * struct mbm_transaction - Memory transaction an MBM event can be configured with. * @name: Name of memory transaction (read, write ...). * @val: The bit (eg. READS_TO_LOCAL_MEM or READS_TO_REMOTE_MEM) used to * represent the memory transaction within an event's configuration. */struct mbm_transaction { char name[32]; u32 val;};
/* Decoded values for each type of memory transaction. */static struct mbm_transaction mbm_transactions[NUM_MBM_TRANSACTIONS] = { {"local_reads", READS_TO_LOCAL_MEM}, {"remote_reads", READS_TO_REMOTE_MEM}, {"local_non_temporal_writes", NON_TEMP_WRITE_TO_LOCAL_MEM}, {"remote_non_temporal_writes", NON_TEMP_WRITE_TO_REMOTE_MEM}, {"local_reads_slow_memory", READS_TO_LOCAL_S_MEM}, {"remote_reads_slow_memory", READS_TO_REMOTE_S_MEM}, {"dirty_victim_writes_all", DIRTY_VICTIMS_TO_ALL_MEM},};
int event_filter_show(struct kernfs_open_file *of, struct seq_file *seq, void *v){ struct mon_evt *mevt = rdt_kn_parent_priv(of->kn); struct rdt_resource *r; bool sep = false; int ret = 0, i;
mutex_lock(&rdtgroup_mutex); rdt_last_cmd_clear();
r = resctrl_arch_get_resource(mevt->rid); if (!resctrl_arch_mbm_cntr_assign_enabled(r)) { rdt_last_cmd_puts("mbm_event counter assignment mode is not enabled\n"); ret = -EINVAL; goto out_unlock; }
for (i = 0; i < NUM_MBM_TRANSACTIONS; i++) { if (mevt->evt_cfg & mbm_transactions[i].val) { if (sep) seq_putc(seq, ','); seq_printf(seq, "%s", mbm_transactions[i].name); sep = true; } } seq_putc(seq, '\n');
out_unlock: mutex_unlock(&rdtgroup_mutex);
return ret;}
int resctrl_mbm_assign_on_mkdir_show(struct kernfs_open_file *of, struct seq_file *s, void *v){ struct rdt_resource *r = rdt_kn_parent_priv(of->kn); int ret = 0;
mutex_lock(&rdtgroup_mutex); rdt_last_cmd_clear();
if (!resctrl_arch_mbm_cntr_assign_enabled(r)) { rdt_last_cmd_puts("mbm_event counter assignment mode is not enabled\n"); ret = -EINVAL; goto out_unlock; }
seq_printf(s, "%u\n", r->mon.mbm_assign_on_mkdir);
out_unlock: mutex_unlock(&rdtgroup_mutex);
return ret;}
ssize_t resctrl_mbm_assign_on_mkdir_write(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off){ struct rdt_resource *r = rdt_kn_parent_priv(of->kn); bool value; int ret;
ret = kstrtobool(buf, &value); if (ret) return ret;
mutex_lock(&rdtgroup_mutex); rdt_last_cmd_clear();
if (!resctrl_arch_mbm_cntr_assign_enabled(r)) { rdt_last_cmd_puts("mbm_event counter assignment mode is not enabled\n"); ret = -EINVAL; goto out_unlock; }
r->mon.mbm_assign_on_mkdir = value;
out_unlock: mutex_unlock(&rdtgroup_mutex);
return ret ?: nbytes;}
/* * mbm_cntr_free_all() - Clear all the counter ID configuration details in the * domain @d. Called when mbm_assign_mode is changed. */static void mbm_cntr_free_all(struct rdt_resource *r, struct rdt_l3_mon_domain *d){ memset(d->cntr_cfg, 0, sizeof(*d->cntr_cfg) * r->mon.num_mbm_cntrs);}
/* * resctrl_reset_rmid_all() - Reset all non-architecture states for all the * supported RMIDs. */static void resctrl_reset_rmid_all(struct rdt_resource *r, struct rdt_l3_mon_domain *d){ u32 idx_limit = resctrl_arch_system_num_rmid_idx(); enum resctrl_event_id evt; int idx;
for_each_mbm_event_id(evt) { if (!resctrl_is_mon_event_enabled(evt)) continue; idx = MBM_STATE_IDX(evt); memset(d->mbm_states[idx], 0, sizeof(*d->mbm_states[0]) * idx_limit); }}
/* * rdtgroup_assign_cntr() - Assign/unassign the counter ID for the event, RMID * pair in the domain. * * Assign the counter if @assign is true else unassign the counter. Reset the * associated non-architectural state. */static void rdtgroup_assign_cntr(struct rdt_resource *r, struct rdt_l3_mon_domain *d, enum resctrl_event_id evtid, u32 rmid, u32 closid, u32 cntr_id, bool assign){ struct mbm_state *m;
resctrl_arch_config_cntr(r, d, evtid, rmid, closid, cntr_id, assign);
m = get_mbm_state(d, closid, rmid, evtid); if (m) memset(m, 0, sizeof(*m));}
/* * rdtgroup_alloc_assign_cntr() - Allocate a counter ID and assign it to the event * pointed to by @mevt and the resctrl group @rdtgrp within the domain @d. * * Return: * 0 on success, < 0 on failure. */static int rdtgroup_alloc_assign_cntr(struct rdt_resource *r, struct rdt_l3_mon_domain *d, struct rdtgroup *rdtgrp, struct mon_evt *mevt){ int cntr_id;
/* No action required if the counter is assigned already. */ cntr_id = mbm_cntr_get(r, d, rdtgrp, mevt->evtid); if (cntr_id >= 0) return 0;
cntr_id = mbm_cntr_alloc(r, d, rdtgrp, mevt->evtid); if (cntr_id < 0) { rdt_last_cmd_printf("Failed to allocate counter for %s in domain %d\n", mevt->name, d->hdr.id); return cntr_id; }
rdtgroup_assign_cntr(r, d, mevt->evtid, rdtgrp->mon.rmid, rdtgrp->closid, cntr_id, true);
return 0;}
/* * rdtgroup_assign_cntr_event() - Assign a hardware counter for the event in * @mevt to the resctrl group @rdtgrp. Assign counters to all domains if @d is * NULL; otherwise, assign the counter to the specified domain @d. * * If all counters in a domain are already in use, rdtgroup_alloc_assign_cntr() * will fail. When attempting to assign counters to all domains, carry on trying * to assign counters after a failure since only some domains may have counters * and the goal is to assign counters where possible. If any counter assignment * fails, return the error from the last failing assignment. * * Return: * 0 on success, < 0 on failure. */static int rdtgroup_assign_cntr_event(struct rdt_l3_mon_domain *d, struct rdtgroup *rdtgrp, struct mon_evt *mevt){ struct rdt_resource *r = resctrl_arch_get_resource(mevt->rid); int ret = 0;
if (!d) { list_for_each_entry(d, &r->mon_domains, hdr.list) { int err;
err = rdtgroup_alloc_assign_cntr(r, d, rdtgrp, mevt); if (err) ret = err; } } else { ret = rdtgroup_alloc_assign_cntr(r, d, rdtgrp, mevt); }
return ret;}
/* * rdtgroup_assign_cntrs() - Assign counters to MBM events. Called when * a new group is created. * * Each group can accommodate two counters per domain: one for the total * event and one for the local event. Assignments may fail due to the limited * number of counters. However, it is not necessary to fail the group creation * and thus no failure is returned. Users have the option to modify the * counter assignments after the group has been created. */void rdtgroup_assign_cntrs(struct rdtgroup *rdtgrp){ struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3);
if (!r->mon_capable || !resctrl_arch_mbm_cntr_assign_enabled(r) || !r->mon.mbm_assign_on_mkdir) return;
if (resctrl_is_mon_event_enabled(QOS_L3_MBM_TOTAL_EVENT_ID)) rdtgroup_assign_cntr_event(NULL, rdtgrp, &mon_event_all[QOS_L3_MBM_TOTAL_EVENT_ID]);
if (resctrl_is_mon_event_enabled(QOS_L3_MBM_LOCAL_EVENT_ID)) rdtgroup_assign_cntr_event(NULL, rdtgrp, &mon_event_all[QOS_L3_MBM_LOCAL_EVENT_ID]);}
/* * rdtgroup_free_unassign_cntr() - Unassign and reset the counter ID configuration * for the event pointed to by @mevt within the domain @d and resctrl group @rdtgrp. */static void rdtgroup_free_unassign_cntr(struct rdt_resource *r, struct rdt_l3_mon_domain *d, struct rdtgroup *rdtgrp, struct mon_evt *mevt){ int cntr_id;
cntr_id = mbm_cntr_get(r, d, rdtgrp, mevt->evtid);
/* If there is no cntr_id assigned, nothing to do */ if (cntr_id < 0) return;
rdtgroup_assign_cntr(r, d, mevt->evtid, rdtgrp->mon.rmid, rdtgrp->closid, cntr_id, false);
mbm_cntr_free(d, cntr_id);}
/* * rdtgroup_unassign_cntr_event() - Unassign a hardware counter associated with * the event structure @mevt from the domain @d and the group @rdtgrp. Unassign * the counters from all the domains if @d is NULL else unassign from @d. */static void rdtgroup_unassign_cntr_event(struct rdt_l3_mon_domain *d, struct rdtgroup *rdtgrp, struct mon_evt *mevt){ struct rdt_resource *r = resctrl_arch_get_resource(mevt->rid);
if (!d) { list_for_each_entry(d, &r->mon_domains, hdr.list) rdtgroup_free_unassign_cntr(r, d, rdtgrp, mevt); } else { rdtgroup_free_unassign_cntr(r, d, rdtgrp, mevt); }}
/* * rdtgroup_unassign_cntrs() - Unassign the counters associated with MBM events. * Called when a group is deleted. */void rdtgroup_unassign_cntrs(struct rdtgroup *rdtgrp){ struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3);
if (!r->mon_capable || !resctrl_arch_mbm_cntr_assign_enabled(r)) return;
if (resctrl_is_mon_event_enabled(QOS_L3_MBM_TOTAL_EVENT_ID)) rdtgroup_unassign_cntr_event(NULL, rdtgrp, &mon_event_all[QOS_L3_MBM_TOTAL_EVENT_ID]);
if (resctrl_is_mon_event_enabled(QOS_L3_MBM_LOCAL_EVENT_ID)) rdtgroup_unassign_cntr_event(NULL, rdtgrp, &mon_event_all[QOS_L3_MBM_LOCAL_EVENT_ID]);}
static int resctrl_parse_mem_transactions(char *tok, u32 *val){ u32 temp_val = 0; char *evt_str; bool found; int i;
next_config: if (!tok || tok[0] == '\0') { *val = temp_val; return 0; }
/* Start processing the strings for each memory transaction type */ evt_str = strim(strsep(&tok, ",")); found = false; for (i = 0; i < NUM_MBM_TRANSACTIONS; i++) { if (!strcmp(mbm_transactions[i].name, evt_str)) { temp_val |= mbm_transactions[i].val; found = true; break; } }
if (!found) { rdt_last_cmd_printf("Invalid memory transaction type %s\n", evt_str); return -EINVAL; }
goto next_config;}
/* * rdtgroup_update_cntr_event - Update the counter assignments for the event * in a group. * @r: Resource to which update needs to be done. * @rdtgrp: Resctrl group. * @evtid: MBM monitor event. */static void rdtgroup_update_cntr_event(struct rdt_resource *r, struct rdtgroup *rdtgrp, enum resctrl_event_id evtid){ struct rdt_l3_mon_domain *d; int cntr_id;
list_for_each_entry(d, &r->mon_domains, hdr.list) { cntr_id = mbm_cntr_get(r, d, rdtgrp, evtid); if (cntr_id >= 0) rdtgroup_assign_cntr(r, d, evtid, rdtgrp->mon.rmid, rdtgrp->closid, cntr_id, true); }}
/* * resctrl_update_cntr_allrdtgrp - Update the counter assignments for the event * for all the groups. * @mevt MBM Monitor event. */static void resctrl_update_cntr_allrdtgrp(struct mon_evt *mevt){ struct rdt_resource *r = resctrl_arch_get_resource(mevt->rid); struct rdtgroup *prgrp, *crgrp;
/* * Find all the groups where the event is assigned and update the * configuration of existing assignments. */ list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) { rdtgroup_update_cntr_event(r, prgrp, mevt->evtid);
list_for_each_entry(crgrp, &prgrp->mon.crdtgrp_list, mon.crdtgrp_list) rdtgroup_update_cntr_event(r, crgrp, mevt->evtid); }}
ssize_t event_filter_write(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off){ struct mon_evt *mevt = rdt_kn_parent_priv(of->kn); struct rdt_resource *r; u32 evt_cfg = 0; int ret = 0;
/* Valid input requires a trailing newline */ if (nbytes == 0 || buf[nbytes - 1] != '\n') return -EINVAL;
buf[nbytes - 1] = '\0';
cpus_read_lock(); mutex_lock(&rdtgroup_mutex);
rdt_last_cmd_clear();
r = resctrl_arch_get_resource(mevt->rid); if (!resctrl_arch_mbm_cntr_assign_enabled(r)) { rdt_last_cmd_puts("mbm_event counter assignment mode is not enabled\n"); ret = -EINVAL; goto out_unlock; } if (!r->mon.mbm_cntr_configurable) { rdt_last_cmd_puts("event_filter is not configurable\n"); ret = -EPERM; goto out_unlock; }
ret = resctrl_parse_mem_transactions(buf, &evt_cfg); if (!ret && mevt->evt_cfg != evt_cfg) { mevt->evt_cfg = evt_cfg; resctrl_update_cntr_allrdtgrp(mevt); }
out_unlock: mutex_unlock(&rdtgroup_mutex); cpus_read_unlock();
return ret ?: nbytes;}
int resctrl_mbm_assign_mode_show(struct kernfs_open_file *of, struct seq_file *s, void *v){ struct rdt_resource *r = rdt_kn_parent_priv(of->kn); bool enabled;
mutex_lock(&rdtgroup_mutex); enabled = resctrl_arch_mbm_cntr_assign_enabled(r);
if (r->mon.mbm_cntr_assignable) { if (enabled) seq_puts(s, "[mbm_event]\n"); else seq_puts(s, "[default]\n");
if (!r->mon.mbm_cntr_assign_fixed) { if (enabled) seq_puts(s, "default\n"); else seq_puts(s, "mbm_event\n"); } } else { seq_puts(s, "[default]\n"); }
mutex_unlock(&rdtgroup_mutex);
return 0;}
ssize_t resctrl_mbm_assign_mode_write(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off){ struct rdt_resource *r = rdt_kn_parent_priv(of->kn); struct rdt_l3_mon_domain *d; int ret = 0; bool enable;
/* Valid input requires a trailing newline */ if (nbytes == 0 || buf[nbytes - 1] != '\n') return -EINVAL;
buf[nbytes - 1] = '\0';
cpus_read_lock(); mutex_lock(&rdtgroup_mutex);
rdt_last_cmd_clear();
if (!strcmp(buf, "default")) { enable = 0; } else if (!strcmp(buf, "mbm_event")) { if (r->mon.mbm_cntr_assignable) { enable = 1; } else { ret = -EINVAL; rdt_last_cmd_puts("mbm_event mode is not supported\n"); goto out_unlock; } } else { ret = -EINVAL; rdt_last_cmd_puts("Unsupported assign mode\n"); goto out_unlock; }
if (enable != resctrl_arch_mbm_cntr_assign_enabled(r)) { if (r->mon.mbm_cntr_assign_fixed) { ret = -EINVAL; rdt_last_cmd_puts("Counter assignment mode is not configurable\n"); goto out_unlock; }
ret = resctrl_arch_mbm_cntr_assign_set(r, enable); if (ret) goto out_unlock;
/* Update the visibility of BMEC related files */ resctrl_bmec_files_show(r, NULL, !enable);
/* * Initialize the default memory transaction values for * total and local events. */ if (resctrl_is_mon_event_enabled(QOS_L3_MBM_TOTAL_EVENT_ID)) mon_event_all[QOS_L3_MBM_TOTAL_EVENT_ID].evt_cfg = r->mon.mbm_cfg_mask; if (resctrl_is_mon_event_enabled(QOS_L3_MBM_LOCAL_EVENT_ID)) mon_event_all[QOS_L3_MBM_LOCAL_EVENT_ID].evt_cfg = r->mon.mbm_cfg_mask & (READS_TO_LOCAL_MEM | READS_TO_LOCAL_S_MEM | NON_TEMP_WRITE_TO_LOCAL_MEM); /* Enable auto assignment when switching to "mbm_event" mode */ if (enable) r->mon.mbm_assign_on_mkdir = true; /* * Reset all the non-achitectural RMID state and assignable counters. */ list_for_each_entry(d, &r->mon_domains, hdr.list) { mbm_cntr_free_all(r, d); resctrl_reset_rmid_all(r, d); } }
out_unlock: mutex_unlock(&rdtgroup_mutex); cpus_read_unlock();
return ret ?: nbytes;}
int resctrl_num_mbm_cntrs_show(struct kernfs_open_file *of, struct seq_file *s, void *v){ struct rdt_resource *r = rdt_kn_parent_priv(of->kn); struct rdt_l3_mon_domain *dom; bool sep = false;
cpus_read_lock(); mutex_lock(&rdtgroup_mutex);
list_for_each_entry(dom, &r->mon_domains, hdr.list) { if (sep) seq_putc(s, ';');
seq_printf(s, "%d=%d", dom->hdr.id, r->mon.num_mbm_cntrs); sep = true; } seq_putc(s, '\n');
mutex_unlock(&rdtgroup_mutex); cpus_read_unlock(); return 0;}
int resctrl_available_mbm_cntrs_show(struct kernfs_open_file *of, struct seq_file *s, void *v){ struct rdt_resource *r = rdt_kn_parent_priv(of->kn); struct rdt_l3_mon_domain *dom; bool sep = false; u32 cntrs, i; int ret = 0;
cpus_read_lock(); mutex_lock(&rdtgroup_mutex);
rdt_last_cmd_clear();
if (!resctrl_arch_mbm_cntr_assign_enabled(r)) { rdt_last_cmd_puts("mbm_event counter assignment mode is not enabled\n"); ret = -EINVAL; goto out_unlock; }
list_for_each_entry(dom, &r->mon_domains, hdr.list) { if (sep) seq_putc(s, ';');
cntrs = 0; for (i = 0; i < r->mon.num_mbm_cntrs; i++) { if (!dom->cntr_cfg[i].rdtgrp) cntrs++; }
seq_printf(s, "%d=%u", dom->hdr.id, cntrs); sep = true; } seq_putc(s, '\n');
out_unlock: mutex_unlock(&rdtgroup_mutex); cpus_read_unlock();
return ret;}
int mbm_L3_assignments_show(struct kernfs_open_file *of, struct seq_file *s, void *v){ struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3); struct rdt_l3_mon_domain *d; struct rdtgroup *rdtgrp; struct mon_evt *mevt; int ret = 0; bool sep;
rdtgrp = rdtgroup_kn_lock_live(of->kn); if (!rdtgrp) { ret = -ENOENT; goto out_unlock; }
rdt_last_cmd_clear(); if (!resctrl_arch_mbm_cntr_assign_enabled(r)) { rdt_last_cmd_puts("mbm_event counter assignment mode is not enabled\n"); ret = -EINVAL; goto out_unlock; }
for_each_mon_event(mevt) { if (mevt->rid != r->rid || !mevt->enabled || !resctrl_is_mbm_event(mevt->evtid)) continue;
sep = false; seq_printf(s, "%s:", mevt->name); list_for_each_entry(d, &r->mon_domains, hdr.list) { if (sep) seq_putc(s, ';');
if (mbm_cntr_get(r, d, rdtgrp, mevt->evtid) < 0) seq_printf(s, "%d=_", d->hdr.id); else seq_printf(s, "%d=e", d->hdr.id);
sep = true; } seq_putc(s, '\n'); }
out_unlock: rdtgroup_kn_unlock(of->kn);
return ret;}
/* * mbm_get_mon_event_by_name() - Return the mon_evt entry for the matching * event name. */static struct mon_evt *mbm_get_mon_event_by_name(struct rdt_resource *r, char *name){ struct mon_evt *mevt;
for_each_mon_event(mevt) { if (mevt->rid == r->rid && mevt->enabled && resctrl_is_mbm_event(mevt->evtid) && !strcmp(mevt->name, name)) return mevt; }
return NULL;}
static int rdtgroup_modify_assign_state(char *assign, struct rdt_l3_mon_domain *d, struct rdtgroup *rdtgrp, struct mon_evt *mevt){ int ret = 0;
if (!assign || strlen(assign) != 1) return -EINVAL;
switch (*assign) { case 'e': ret = rdtgroup_assign_cntr_event(d, rdtgrp, mevt); break; case '_': rdtgroup_unassign_cntr_event(d, rdtgrp, mevt); break; default: ret = -EINVAL; break; }
return ret;}
static int resctrl_parse_mbm_assignment(struct rdt_resource *r, struct rdtgroup *rdtgrp, char *event, char *tok){ struct rdt_l3_mon_domain *d; unsigned long dom_id = 0; char *dom_str, *id_str; struct mon_evt *mevt; int ret;
mevt = mbm_get_mon_event_by_name(r, event); if (!mevt) { rdt_last_cmd_printf("Invalid event %s\n", event); return -ENOENT; }
next: if (!tok || tok[0] == '\0') return 0;
/* Start processing the strings for each domain */ dom_str = strim(strsep(&tok, ";"));
id_str = strsep(&dom_str, "=");
/* Check for domain id '*' which means all domains */ if (id_str && *id_str == '*') { ret = rdtgroup_modify_assign_state(dom_str, NULL, rdtgrp, mevt); if (ret) rdt_last_cmd_printf("Assign operation '%s:*=%s' failed\n", event, dom_str); return ret; } else if (!id_str || kstrtoul(id_str, 10, &dom_id)) { rdt_last_cmd_puts("Missing domain id\n"); return -EINVAL; }
/* Verify if the dom_id is valid */ list_for_each_entry(d, &r->mon_domains, hdr.list) { if (d->hdr.id == dom_id) { ret = rdtgroup_modify_assign_state(dom_str, d, rdtgrp, mevt); if (ret) { rdt_last_cmd_printf("Assign operation '%s:%ld=%s' failed\n", event, dom_id, dom_str); return ret; } goto next; } }
rdt_last_cmd_printf("Invalid domain id %ld\n", dom_id); return -EINVAL;}
ssize_t mbm_L3_assignments_write(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off){ struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3); struct rdtgroup *rdtgrp; char *token, *event; int ret = 0;
/* Valid input requires a trailing newline */ if (nbytes == 0 || buf[nbytes - 1] != '\n') return -EINVAL;
buf[nbytes - 1] = '\0';
rdtgrp = rdtgroup_kn_lock_live(of->kn); if (!rdtgrp) { rdtgroup_kn_unlock(of->kn); return -ENOENT; } rdt_last_cmd_clear();
if (!resctrl_arch_mbm_cntr_assign_enabled(r)) { rdt_last_cmd_puts("mbm_event mode is not enabled\n"); rdtgroup_kn_unlock(of->kn); return -EINVAL; }
while ((token = strsep(&buf, "\n")) != NULL) { /* * The write command follows the following format: * "<Event>:<Domain ID>=<Assignment state>" * Extract the event name first. */ event = strsep(&token, ":");
ret = resctrl_parse_mbm_assignment(r, rdtgrp, event, token); if (ret) break; }
rdtgroup_kn_unlock(of->kn);
return ret ?: nbytes;}
static int closid_num_dirty_rmid_alloc(struct rdt_resource *r){ if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) { u32 num_closid = resctrl_arch_get_num_closid(r); u32 *tmp;
/* For ARM memory ordering access to closid_num_dirty_rmid */ mutex_lock(&rdtgroup_mutex);
/* * 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) { mutex_unlock(&rdtgroup_mutex); return -ENOMEM; }
closid_num_dirty_rmid = tmp;
mutex_unlock(&rdtgroup_mutex); }
return 0;}
static void closid_num_dirty_rmid_free(void){ if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) { mutex_lock(&rdtgroup_mutex); kfree(closid_num_dirty_rmid); closid_num_dirty_rmid = NULL; mutex_unlock(&rdtgroup_mutex); }}
/** * resctrl_l3_mon_resource_init() - Initialise global monitoring structures. * * Allocate and initialise global monitor resources that do not belong to a * specific domain. i.e. the closid_num_dirty_rmid[] used to find the CLOSID * with the cleanest set of RMIDs. * Called once during boot after the struct rdt_resource's have been configured * but before the filesystem is mounted. * Resctrl's cpuhp callbacks may be called before this point to bring a domain * online. * * Return: 0 for success, or -ENOMEM. */int resctrl_l3_mon_resource_init(void){ struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3); int ret;
if (!r->mon_capable) return 0;
ret = closid_num_dirty_rmid_alloc(r); if (ret) return ret;
if (resctrl_arch_is_evt_configurable(QOS_L3_MBM_TOTAL_EVENT_ID)) { mon_event_all[QOS_L3_MBM_TOTAL_EVENT_ID].configurable = true; resctrl_file_fflags_init("mbm_total_bytes_config", RFTYPE_MON_INFO | RFTYPE_RES_CACHE); } if (resctrl_arch_is_evt_configurable(QOS_L3_MBM_LOCAL_EVENT_ID)) { mon_event_all[QOS_L3_MBM_LOCAL_EVENT_ID].configurable = true; resctrl_file_fflags_init("mbm_local_bytes_config", RFTYPE_MON_INFO | RFTYPE_RES_CACHE); }
if (resctrl_is_mon_event_enabled(QOS_L3_MBM_LOCAL_EVENT_ID)) mba_mbps_default_event = QOS_L3_MBM_LOCAL_EVENT_ID; else if (resctrl_is_mon_event_enabled(QOS_L3_MBM_TOTAL_EVENT_ID)) mba_mbps_default_event = QOS_L3_MBM_TOTAL_EVENT_ID;
if (r->mon.mbm_cntr_assignable) { if (resctrl_is_mon_event_enabled(QOS_L3_MBM_TOTAL_EVENT_ID)) mon_event_all[QOS_L3_MBM_TOTAL_EVENT_ID].evt_cfg = r->mon.mbm_cfg_mask; if (resctrl_is_mon_event_enabled(QOS_L3_MBM_LOCAL_EVENT_ID)) mon_event_all[QOS_L3_MBM_LOCAL_EVENT_ID].evt_cfg = r->mon.mbm_cfg_mask & (READS_TO_LOCAL_MEM | READS_TO_LOCAL_S_MEM | NON_TEMP_WRITE_TO_LOCAL_MEM); r->mon.mbm_assign_on_mkdir = true; resctrl_file_fflags_init("num_mbm_cntrs", RFTYPE_MON_INFO | RFTYPE_RES_CACHE); resctrl_file_fflags_init("available_mbm_cntrs", RFTYPE_MON_INFO | RFTYPE_RES_CACHE); resctrl_file_fflags_init("event_filter", RFTYPE_ASSIGN_CONFIG); if (r->mon.mbm_cntr_configurable) resctrl_file_mode_init("event_filter", 0644); resctrl_file_fflags_init("mbm_assign_on_mkdir", RFTYPE_MON_INFO | RFTYPE_RES_CACHE); resctrl_file_fflags_init("mbm_L3_assignments", RFTYPE_MON_BASE); }
return 0;}
void resctrl_l3_mon_resource_exit(void){ struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3);
if (!r->mon_capable) return;
closid_num_dirty_rmid_free();}