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![Juan Quintela](/assets/img/avatar_default.png)
Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20230511141208.17779-3-quintela@redhat.com>
602 lines
15 KiB
C
602 lines
15 KiB
C
/*
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* Dirty page rate limit implementation code
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*
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* Copyright (c) 2022 CHINA TELECOM CO.,LTD.
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*
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* Authors:
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* Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
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*
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* This work is licensed under the terms of the GNU GPL, version 2 or later.
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* See the COPYING file in the top-level directory.
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*/
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#include "qemu/osdep.h"
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#include "qemu/main-loop.h"
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#include "qapi/qapi-commands-migration.h"
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#include "qapi/qmp/qdict.h"
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#include "qapi/error.h"
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#include "sysemu/dirtyrate.h"
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#include "sysemu/dirtylimit.h"
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#include "monitor/hmp.h"
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#include "monitor/monitor.h"
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#include "exec/memory.h"
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#include "exec/target_page.h"
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#include "hw/boards.h"
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#include "sysemu/kvm.h"
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#include "trace.h"
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/*
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* Dirtylimit stop working if dirty page rate error
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* value less than DIRTYLIMIT_TOLERANCE_RANGE
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*/
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#define DIRTYLIMIT_TOLERANCE_RANGE 25 /* MB/s */
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/*
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* Plus or minus vcpu sleep time linearly if dirty
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* page rate error value percentage over
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* DIRTYLIMIT_LINEAR_ADJUSTMENT_PCT.
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* Otherwise, plus or minus a fixed vcpu sleep time.
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*/
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#define DIRTYLIMIT_LINEAR_ADJUSTMENT_PCT 50
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/*
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* Max vcpu sleep time percentage during a cycle
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* composed of dirty ring full and sleep time.
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*/
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#define DIRTYLIMIT_THROTTLE_PCT_MAX 99
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struct {
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VcpuStat stat;
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bool running;
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QemuThread thread;
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} *vcpu_dirty_rate_stat;
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typedef struct VcpuDirtyLimitState {
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int cpu_index;
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bool enabled;
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/*
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* Quota dirty page rate, unit is MB/s
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* zero if not enabled.
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*/
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uint64_t quota;
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} VcpuDirtyLimitState;
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struct {
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VcpuDirtyLimitState *states;
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/* Max cpus number configured by user */
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int max_cpus;
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/* Number of vcpu under dirtylimit */
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int limited_nvcpu;
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} *dirtylimit_state;
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/* protect dirtylimit_state */
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static QemuMutex dirtylimit_mutex;
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/* dirtylimit thread quit if dirtylimit_quit is true */
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static bool dirtylimit_quit;
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static void vcpu_dirty_rate_stat_collect(void)
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{
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VcpuStat stat;
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int i = 0;
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/* calculate vcpu dirtyrate */
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vcpu_calculate_dirtyrate(DIRTYLIMIT_CALC_TIME_MS,
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&stat,
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GLOBAL_DIRTY_LIMIT,
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false);
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for (i = 0; i < stat.nvcpu; i++) {
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vcpu_dirty_rate_stat->stat.rates[i].id = i;
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vcpu_dirty_rate_stat->stat.rates[i].dirty_rate =
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stat.rates[i].dirty_rate;
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}
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free(stat.rates);
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}
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static void *vcpu_dirty_rate_stat_thread(void *opaque)
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{
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rcu_register_thread();
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/* start log sync */
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global_dirty_log_change(GLOBAL_DIRTY_LIMIT, true);
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while (qatomic_read(&vcpu_dirty_rate_stat->running)) {
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vcpu_dirty_rate_stat_collect();
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if (dirtylimit_in_service()) {
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dirtylimit_process();
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}
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}
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/* stop log sync */
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global_dirty_log_change(GLOBAL_DIRTY_LIMIT, false);
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rcu_unregister_thread();
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return NULL;
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}
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int64_t vcpu_dirty_rate_get(int cpu_index)
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{
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DirtyRateVcpu *rates = vcpu_dirty_rate_stat->stat.rates;
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return qatomic_read_i64(&rates[cpu_index].dirty_rate);
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}
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void vcpu_dirty_rate_stat_start(void)
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{
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if (qatomic_read(&vcpu_dirty_rate_stat->running)) {
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return;
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}
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qatomic_set(&vcpu_dirty_rate_stat->running, 1);
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qemu_thread_create(&vcpu_dirty_rate_stat->thread,
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"dirtyrate-stat",
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vcpu_dirty_rate_stat_thread,
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NULL,
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QEMU_THREAD_JOINABLE);
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}
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void vcpu_dirty_rate_stat_stop(void)
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{
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qatomic_set(&vcpu_dirty_rate_stat->running, 0);
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dirtylimit_state_unlock();
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qemu_mutex_unlock_iothread();
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qemu_thread_join(&vcpu_dirty_rate_stat->thread);
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qemu_mutex_lock_iothread();
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dirtylimit_state_lock();
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}
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void vcpu_dirty_rate_stat_initialize(void)
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{
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MachineState *ms = MACHINE(qdev_get_machine());
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int max_cpus = ms->smp.max_cpus;
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vcpu_dirty_rate_stat =
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g_malloc0(sizeof(*vcpu_dirty_rate_stat));
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vcpu_dirty_rate_stat->stat.nvcpu = max_cpus;
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vcpu_dirty_rate_stat->stat.rates =
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g_new0(DirtyRateVcpu, max_cpus);
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vcpu_dirty_rate_stat->running = false;
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}
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void vcpu_dirty_rate_stat_finalize(void)
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{
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free(vcpu_dirty_rate_stat->stat.rates);
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vcpu_dirty_rate_stat->stat.rates = NULL;
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free(vcpu_dirty_rate_stat);
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vcpu_dirty_rate_stat = NULL;
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}
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void dirtylimit_state_lock(void)
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{
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qemu_mutex_lock(&dirtylimit_mutex);
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}
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void dirtylimit_state_unlock(void)
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{
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qemu_mutex_unlock(&dirtylimit_mutex);
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}
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static void
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__attribute__((__constructor__)) dirtylimit_mutex_init(void)
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{
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qemu_mutex_init(&dirtylimit_mutex);
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}
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static inline VcpuDirtyLimitState *dirtylimit_vcpu_get_state(int cpu_index)
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{
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return &dirtylimit_state->states[cpu_index];
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}
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void dirtylimit_state_initialize(void)
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{
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MachineState *ms = MACHINE(qdev_get_machine());
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int max_cpus = ms->smp.max_cpus;
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int i;
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dirtylimit_state = g_malloc0(sizeof(*dirtylimit_state));
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dirtylimit_state->states =
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g_new0(VcpuDirtyLimitState, max_cpus);
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for (i = 0; i < max_cpus; i++) {
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dirtylimit_state->states[i].cpu_index = i;
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}
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dirtylimit_state->max_cpus = max_cpus;
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trace_dirtylimit_state_initialize(max_cpus);
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}
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void dirtylimit_state_finalize(void)
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{
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free(dirtylimit_state->states);
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dirtylimit_state->states = NULL;
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free(dirtylimit_state);
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dirtylimit_state = NULL;
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trace_dirtylimit_state_finalize();
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}
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bool dirtylimit_in_service(void)
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{
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return !!dirtylimit_state;
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}
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bool dirtylimit_vcpu_index_valid(int cpu_index)
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{
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MachineState *ms = MACHINE(qdev_get_machine());
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return !(cpu_index < 0 ||
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cpu_index >= ms->smp.max_cpus);
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}
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static uint64_t dirtylimit_dirty_ring_full_time(uint64_t dirtyrate)
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{
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static uint64_t max_dirtyrate;
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uint64_t dirty_ring_size_MiB;
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dirty_ring_size_MiB = qemu_target_pages_to_MiB(kvm_dirty_ring_size());
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if (max_dirtyrate < dirtyrate) {
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max_dirtyrate = dirtyrate;
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}
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return dirty_ring_size_MiB * 1000000 / max_dirtyrate;
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}
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static inline bool dirtylimit_done(uint64_t quota,
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uint64_t current)
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{
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uint64_t min, max;
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min = MIN(quota, current);
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max = MAX(quota, current);
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return ((max - min) <= DIRTYLIMIT_TOLERANCE_RANGE) ? true : false;
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}
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static inline bool
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dirtylimit_need_linear_adjustment(uint64_t quota,
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uint64_t current)
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{
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uint64_t min, max;
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min = MIN(quota, current);
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max = MAX(quota, current);
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return ((max - min) * 100 / max) > DIRTYLIMIT_LINEAR_ADJUSTMENT_PCT;
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}
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static void dirtylimit_set_throttle(CPUState *cpu,
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uint64_t quota,
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uint64_t current)
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{
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int64_t ring_full_time_us = 0;
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uint64_t sleep_pct = 0;
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uint64_t throttle_us = 0;
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if (current == 0) {
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cpu->throttle_us_per_full = 0;
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return;
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}
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ring_full_time_us = dirtylimit_dirty_ring_full_time(current);
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if (dirtylimit_need_linear_adjustment(quota, current)) {
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if (quota < current) {
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sleep_pct = (current - quota) * 100 / current;
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throttle_us =
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ring_full_time_us * sleep_pct / (double)(100 - sleep_pct);
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cpu->throttle_us_per_full += throttle_us;
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} else {
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sleep_pct = (quota - current) * 100 / quota;
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throttle_us =
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ring_full_time_us * sleep_pct / (double)(100 - sleep_pct);
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cpu->throttle_us_per_full -= throttle_us;
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}
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trace_dirtylimit_throttle_pct(cpu->cpu_index,
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sleep_pct,
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throttle_us);
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} else {
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if (quota < current) {
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cpu->throttle_us_per_full += ring_full_time_us / 10;
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} else {
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cpu->throttle_us_per_full -= ring_full_time_us / 10;
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}
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}
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/*
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* TODO: in the big kvm_dirty_ring_size case (eg: 65536, or other scenario),
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* current dirty page rate may never reach the quota, we should stop
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* increasing sleep time?
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*/
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cpu->throttle_us_per_full = MIN(cpu->throttle_us_per_full,
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ring_full_time_us * DIRTYLIMIT_THROTTLE_PCT_MAX);
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cpu->throttle_us_per_full = MAX(cpu->throttle_us_per_full, 0);
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}
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static void dirtylimit_adjust_throttle(CPUState *cpu)
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{
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uint64_t quota = 0;
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uint64_t current = 0;
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int cpu_index = cpu->cpu_index;
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quota = dirtylimit_vcpu_get_state(cpu_index)->quota;
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current = vcpu_dirty_rate_get(cpu_index);
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if (!dirtylimit_done(quota, current)) {
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dirtylimit_set_throttle(cpu, quota, current);
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}
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return;
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}
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void dirtylimit_process(void)
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{
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CPUState *cpu;
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if (!qatomic_read(&dirtylimit_quit)) {
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dirtylimit_state_lock();
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if (!dirtylimit_in_service()) {
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dirtylimit_state_unlock();
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return;
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}
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CPU_FOREACH(cpu) {
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if (!dirtylimit_vcpu_get_state(cpu->cpu_index)->enabled) {
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continue;
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}
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dirtylimit_adjust_throttle(cpu);
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}
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dirtylimit_state_unlock();
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}
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}
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void dirtylimit_change(bool start)
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{
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if (start) {
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qatomic_set(&dirtylimit_quit, 0);
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} else {
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qatomic_set(&dirtylimit_quit, 1);
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}
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}
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void dirtylimit_set_vcpu(int cpu_index,
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uint64_t quota,
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bool enable)
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{
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trace_dirtylimit_set_vcpu(cpu_index, quota);
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if (enable) {
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dirtylimit_state->states[cpu_index].quota = quota;
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if (!dirtylimit_vcpu_get_state(cpu_index)->enabled) {
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dirtylimit_state->limited_nvcpu++;
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}
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} else {
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dirtylimit_state->states[cpu_index].quota = 0;
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if (dirtylimit_state->states[cpu_index].enabled) {
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dirtylimit_state->limited_nvcpu--;
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}
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}
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dirtylimit_state->states[cpu_index].enabled = enable;
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}
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void dirtylimit_set_all(uint64_t quota,
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bool enable)
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{
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MachineState *ms = MACHINE(qdev_get_machine());
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int max_cpus = ms->smp.max_cpus;
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int i;
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for (i = 0; i < max_cpus; i++) {
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dirtylimit_set_vcpu(i, quota, enable);
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}
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}
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void dirtylimit_vcpu_execute(CPUState *cpu)
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{
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if (dirtylimit_in_service() &&
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dirtylimit_vcpu_get_state(cpu->cpu_index)->enabled &&
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cpu->throttle_us_per_full) {
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trace_dirtylimit_vcpu_execute(cpu->cpu_index,
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cpu->throttle_us_per_full);
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usleep(cpu->throttle_us_per_full);
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}
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}
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static void dirtylimit_init(void)
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{
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dirtylimit_state_initialize();
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dirtylimit_change(true);
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vcpu_dirty_rate_stat_initialize();
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vcpu_dirty_rate_stat_start();
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}
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static void dirtylimit_cleanup(void)
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{
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vcpu_dirty_rate_stat_stop();
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vcpu_dirty_rate_stat_finalize();
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dirtylimit_change(false);
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dirtylimit_state_finalize();
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}
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void qmp_cancel_vcpu_dirty_limit(bool has_cpu_index,
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int64_t cpu_index,
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Error **errp)
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{
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if (!kvm_enabled() || !kvm_dirty_ring_enabled()) {
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return;
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}
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if (has_cpu_index && !dirtylimit_vcpu_index_valid(cpu_index)) {
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error_setg(errp, "incorrect cpu index specified");
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return;
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}
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if (!dirtylimit_in_service()) {
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return;
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}
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dirtylimit_state_lock();
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if (has_cpu_index) {
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dirtylimit_set_vcpu(cpu_index, 0, false);
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} else {
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dirtylimit_set_all(0, false);
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}
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if (!dirtylimit_state->limited_nvcpu) {
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dirtylimit_cleanup();
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}
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dirtylimit_state_unlock();
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}
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void hmp_cancel_vcpu_dirty_limit(Monitor *mon, const QDict *qdict)
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{
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int64_t cpu_index = qdict_get_try_int(qdict, "cpu_index", -1);
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Error *err = NULL;
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qmp_cancel_vcpu_dirty_limit(!!(cpu_index != -1), cpu_index, &err);
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if (err) {
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hmp_handle_error(mon, err);
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return;
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}
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monitor_printf(mon, "[Please use 'info vcpu_dirty_limit' to query "
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"dirty limit for virtual CPU]\n");
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}
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void qmp_set_vcpu_dirty_limit(bool has_cpu_index,
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int64_t cpu_index,
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uint64_t dirty_rate,
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Error **errp)
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{
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if (!kvm_enabled() || !kvm_dirty_ring_enabled()) {
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error_setg(errp, "dirty page limit feature requires KVM with"
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" accelerator property 'dirty-ring-size' set'");
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return;
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}
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if (has_cpu_index && !dirtylimit_vcpu_index_valid(cpu_index)) {
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error_setg(errp, "incorrect cpu index specified");
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return;
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}
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if (!dirty_rate) {
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qmp_cancel_vcpu_dirty_limit(has_cpu_index, cpu_index, errp);
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return;
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}
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dirtylimit_state_lock();
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if (!dirtylimit_in_service()) {
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dirtylimit_init();
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}
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if (has_cpu_index) {
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dirtylimit_set_vcpu(cpu_index, dirty_rate, true);
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} else {
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dirtylimit_set_all(dirty_rate, true);
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}
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dirtylimit_state_unlock();
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}
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void hmp_set_vcpu_dirty_limit(Monitor *mon, const QDict *qdict)
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{
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int64_t dirty_rate = qdict_get_int(qdict, "dirty_rate");
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int64_t cpu_index = qdict_get_try_int(qdict, "cpu_index", -1);
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Error *err = NULL;
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qmp_set_vcpu_dirty_limit(!!(cpu_index != -1), cpu_index, dirty_rate, &err);
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if (err) {
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hmp_handle_error(mon, err);
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return;
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}
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monitor_printf(mon, "[Please use 'info vcpu_dirty_limit' to query "
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"dirty limit for virtual CPU]\n");
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}
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static struct DirtyLimitInfo *dirtylimit_query_vcpu(int cpu_index)
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{
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DirtyLimitInfo *info = NULL;
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info = g_malloc0(sizeof(*info));
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info->cpu_index = cpu_index;
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info->limit_rate = dirtylimit_vcpu_get_state(cpu_index)->quota;
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info->current_rate = vcpu_dirty_rate_get(cpu_index);
|
|
|
|
return info;
|
|
}
|
|
|
|
static struct DirtyLimitInfoList *dirtylimit_query_all(void)
|
|
{
|
|
int i, index;
|
|
DirtyLimitInfo *info = NULL;
|
|
DirtyLimitInfoList *head = NULL, **tail = &head;
|
|
|
|
dirtylimit_state_lock();
|
|
|
|
if (!dirtylimit_in_service()) {
|
|
dirtylimit_state_unlock();
|
|
return NULL;
|
|
}
|
|
|
|
for (i = 0; i < dirtylimit_state->max_cpus; i++) {
|
|
index = dirtylimit_state->states[i].cpu_index;
|
|
if (dirtylimit_vcpu_get_state(index)->enabled) {
|
|
info = dirtylimit_query_vcpu(index);
|
|
QAPI_LIST_APPEND(tail, info);
|
|
}
|
|
}
|
|
|
|
dirtylimit_state_unlock();
|
|
|
|
return head;
|
|
}
|
|
|
|
struct DirtyLimitInfoList *qmp_query_vcpu_dirty_limit(Error **errp)
|
|
{
|
|
if (!dirtylimit_in_service()) {
|
|
return NULL;
|
|
}
|
|
|
|
return dirtylimit_query_all();
|
|
}
|
|
|
|
void hmp_info_vcpu_dirty_limit(Monitor *mon, const QDict *qdict)
|
|
{
|
|
DirtyLimitInfoList *limit, *head, *info = NULL;
|
|
Error *err = NULL;
|
|
|
|
if (!dirtylimit_in_service()) {
|
|
monitor_printf(mon, "Dirty page limit not enabled!\n");
|
|
return;
|
|
}
|
|
|
|
info = qmp_query_vcpu_dirty_limit(&err);
|
|
if (err) {
|
|
hmp_handle_error(mon, err);
|
|
return;
|
|
}
|
|
|
|
head = info;
|
|
for (limit = head; limit != NULL; limit = limit->next) {
|
|
monitor_printf(mon, "vcpu[%"PRIi64"], limit rate %"PRIi64 " (MB/s),"
|
|
" current rate %"PRIi64 " (MB/s)\n",
|
|
limit->value->cpu_index,
|
|
limit->value->limit_rate,
|
|
limit->value->current_rate);
|
|
}
|
|
|
|
g_free(info);
|
|
}
|