diff options
Diffstat (limited to 'arch/x86/kernel/cpu/resctrl/monitor.c')
| -rw-r--r-- | arch/x86/kernel/cpu/resctrl/monitor.c | 931 |
1 files changed, 125 insertions, 806 deletions
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index c34a35ec0f03..c261558276cd 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -15,63 +15,16 @@ * 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 <linux/resctrl.h> #include <asm/cpu_device_id.h> -#include <asm/resctrl.h> +#include <asm/msr.h> #include "internal.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. @@ -83,21 +36,12 @@ bool rdt_mon_capable; */ 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. + * The correction factor table is documented in Documentation/filesystems/resctrl.rst. * If rmid > rmid threshold, MBM total and local values should be multiplied * by the correction factor. * @@ -146,6 +90,7 @@ static const struct mbm_correction_factor_table { }; 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) @@ -158,33 +103,42 @@ static inline u64 get_corrected_mbm_count(u32 rmid, unsigned long 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. + * 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). * - * The domain's rmid_busy_llc and rmid_ptrs[] are sized by index. The arch code - * must accept an attempt to read every index. + * 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 inline struct rmid_entry *__rmid_entry(u32 idx) +static int logical_rmid_to_physical_rmid(int cpu, int lrmid) { - struct rmid_entry *entry; - u32 closid, rmid; - - entry = &rmid_ptrs[idx]; - resctrl_arch_rmid_idx_decode(idx, &closid, &rmid); + struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl; - WARN_ON_ONCE(entry->closid != closid); - WARN_ON_ONCE(entry->rmid != rmid); + if (snc_nodes_per_l3_cache == 1) + return lrmid; - return entry; + return lrmid + (cpu_to_node(cpu) % snc_nodes_per_l3_cache) * r->num_rmid; } -static int __rmid_read(u32 rmid, enum resctrl_event_id eventid, u64 *val) +static int __rmid_read_phys(u32 prmid, enum resctrl_event_id eventid, u64 *val) { u64 msr_val; @@ -196,8 +150,8 @@ static int __rmid_read(u32 rmid, enum resctrl_event_id eventid, u64 *val) * IA32_QM_CTR.Error (bit 63) and IA32_QM_CTR.Unavailable (bit 62) * are error bits. */ - wrmsr(MSR_IA32_QM_EVTSEL, eventid, rmid); - rdmsrl(MSR_IA32_QM_CTR, msr_val); + wrmsr(MSR_IA32_QM_EVTSEL, eventid, prmid); + rdmsrq(MSR_IA32_QM_CTR, msr_val); if (msr_val & RMID_VAL_ERROR) return -EIO; @@ -208,7 +162,7 @@ static int __rmid_read(u32 rmid, enum resctrl_event_id eventid, u64 *val) return 0; } -static struct arch_mbm_state *get_arch_mbm_state(struct rdt_hw_domain *hw_dom, +static struct arch_mbm_state *get_arch_mbm_state(struct rdt_hw_mon_domain *hw_dom, u32 rmid, enum resctrl_event_id eventid) { @@ -219,27 +173,29 @@ static struct arch_mbm_state *get_arch_mbm_state(struct rdt_hw_domain *hw_dom, return &hw_dom->arch_mbm_total[rmid]; case QOS_L3_MBM_LOCAL_EVENT_ID: return &hw_dom->arch_mbm_local[rmid]; + default: + /* Never expect to get here */ + WARN_ON_ONCE(1); + return NULL; } - - /* Never expect to get here */ - WARN_ON_ONCE(1); - - return NULL; } -void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_domain *d, +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_domain *hw_dom = resctrl_to_arch_dom(d); + struct rdt_hw_mon_domain *hw_dom = resctrl_to_arch_mon_dom(d); + int cpu = cpumask_any(&d->hdr.cpu_mask); struct arch_mbm_state *am; + u32 prmid; am = get_arch_mbm_state(hw_dom, rmid, eventid); if (am) { memset(am, 0, sizeof(*am)); + prmid = logical_rmid_to_physical_rmid(cpu, rmid); /* Record any initial, non-zero count value. */ - __rmid_read(rmid, eventid, &am->prev_msr); + __rmid_read_phys(prmid, eventid, &am->prev_msr); } } @@ -247,15 +203,15 @@ void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_domain *d, * 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_domain *d) +void resctrl_arch_reset_rmid_all(struct rdt_resource *r, struct rdt_mon_domain *d) { - struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d); + struct rdt_hw_mon_domain *hw_dom = resctrl_to_arch_mon_dom(d); - if (is_mbm_total_enabled()) + if (resctrl_arch_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()) + if (resctrl_arch_is_mbm_local_enabled()) memset(hw_dom->arch_mbm_local, 0, sizeof(*hw_dom->arch_mbm_local) * r->num_rmid); } @@ -268,22 +224,22 @@ static u64 mbm_overflow_count(u64 prev_msr, u64 cur_msr, unsigned int width) return chunks >> shift; } -int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain *d, +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); - struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d); + 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(); - if (!cpumask_test_cpu(smp_processor_id(), &d->cpu_mask)) - return -EINVAL; - - ret = __rmid_read(rmid, eventid, &msr_val); + prmid = logical_rmid_to_physical_rmid(cpu, rmid); + ret = __rmid_read_phys(prmid, eventid, &msr_val); if (ret) return ret; @@ -302,705 +258,87 @@ int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain *d, 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 + * 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 __check_limbo(struct rdt_domain *d, bool force_free) +void arch_mon_domain_online(struct rdt_resource *r, struct rdt_mon_domain *d) { - 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); - } - - 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_domain *d) -{ - u32 idx_limit = resctrl_arch_system_num_rmid_idx(); - - return find_first_bit(d->rmid_busy_llc, idx_limit) != idx_limit; + if (snc_nodes_per_l3_cache > 1) + msr_clear_bit(MSR_RMID_SNC_CONFIG, 0); } -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_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->domains, 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 (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_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) -{ - struct mbm_state *m; - 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; - } - - 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; -} - -/* - * 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; -} +/* 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), + {} +}; /* - * This is scheduled by mon_event_read() to read the CQM/MBM counters - * on a domain. + * 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). */ -void mon_event_count(void *info) +static __init int snc_get_config(void) { - struct rdtgroup *rdtgrp, *entry; - struct rmid_read *rr = info; - struct list_head *head; + 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; - 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_domain *dom_mbm) -{ - u32 closid, rmid, cur_msr_val, new_msr_val; - struct mbm_state *pmbm_data, *cmbm_data; - struct rdt_resource *r_mba; - struct rdt_domain *dom_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_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_domain *d, - u32 closid, u32 rmid) -{ - struct rmid_read rr; - - rr.first = false; - 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_domain *d; + if (!x86_match_cpu(snc_cpu_ids) || !ci) + return 1; cpus_read_lock(); - mutex_lock(&rdtgroup_mutex); - - d = container_of(work, struct rdt_domain, cqm_limbo.work); - - __check_limbo(d, false); - - if (has_busy_rmid(d)) { - d->cqm_work_cpu = cpumask_any_housekeeping(&d->cpu_mask, - RESCTRL_PICK_ANY_CPU); - schedule_delayed_work_on(d->cqm_work_cpu, &d->cqm_limbo, - delay); - } - - mutex_unlock(&rdtgroup_mutex); + if (num_online_cpus() != num_present_cpus()) + pr_warn("Some CPUs offline, SNC detection may be incorrect\n"); 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_domain *dom, unsigned long delay_ms, - int exclude_cpu) -{ - unsigned long delay = msecs_to_jiffies(delay_ms); - int cpu; + node0_cpumask = cpumask_of_node(cpu_to_node(0)); - cpu = cpumask_any_housekeeping(&dom->cpu_mask, exclude_cpu); - dom->cqm_work_cpu = cpu; + cpus_per_node = cpumask_weight(node0_cpumask); + cpus_per_l3 = cpumask_weight(&ci->shared_cpu_map); - if (cpu < nr_cpu_ids) - schedule_delayed_work_on(cpu, &dom->cqm_limbo, delay); -} + if (!cpus_per_node || !cpus_per_l3) + return 1; -void mbm_handle_overflow(struct work_struct *work) -{ - unsigned long delay = msecs_to_jiffies(MBM_OVERFLOW_INTERVAL); - struct rdtgroup *prgrp, *crgrp; - struct list_head *head; - struct rdt_resource *r; - struct rdt_domain *d; + ret = cpus_per_l3 / cpus_per_node; - 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_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->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_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->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; + /* sanity check: Only valid results are 1, 2, 3, 4, 6 */ + switch (ret) { + case 1: + break; + case 2 ... 4: + case 6: + 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; } - 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); + return ret; } int __init rdt_get_mon_l3_config(struct rdt_resource *r) @@ -1008,11 +346,12 @@ 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; - r->num_rmid = boot_cpu_data.x86_cache_max_rmid + 1; + hw_res->mon_scale = boot_cpu_data.x86_cache_occ_scale / snc_nodes_per_l3_cache; + r->num_rmid = (boot_cpu_data.x86_cache_max_rmid + 1) / snc_nodes_per_l3_cache; hw_res->mbm_width = MBM_CNTR_WIDTH_BASE; if (mbm_offset > 0 && mbm_offset <= MBM_CNTR_WIDTH_OFFSET_MAX) @@ -1036,39 +375,19 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r) */ 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"); - } + r->mbm_cfg_mask = ecx & MAX_EVT_CONFIG_BITS; } - 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; |