diff options
Diffstat (limited to 'softmmu/dirtylimit.c')
| -rw-r--r-- | softmmu/dirtylimit.c | 291 |
1 files changed, 291 insertions, 0 deletions
diff --git a/softmmu/dirtylimit.c b/softmmu/dirtylimit.c index ebdc064..e5a4f97 100644 --- a/softmmu/dirtylimit.c +++ b/softmmu/dirtylimit.c @@ -18,6 +18,26 @@ #include "sysemu/dirtylimit.h" #include "exec/memory.h" #include "hw/boards.h" +#include "sysemu/kvm.h" +#include "trace.h" + +/* + * Dirtylimit stop working if dirty page rate error + * value less than DIRTYLIMIT_TOLERANCE_RANGE + */ +#define DIRTYLIMIT_TOLERANCE_RANGE 25 /* MB/s */ +/* + * Plus or minus vcpu sleep time linearly if dirty + * page rate error value percentage over + * DIRTYLIMIT_LINEAR_ADJUSTMENT_PCT. + * Otherwise, plus or minus a fixed vcpu sleep time. + */ +#define DIRTYLIMIT_LINEAR_ADJUSTMENT_PCT 50 +/* + * Max vcpu sleep time percentage during a cycle + * composed of dirty ring full and sleep time. + */ +#define DIRTYLIMIT_THROTTLE_PCT_MAX 99 struct { VcpuStat stat; @@ -25,6 +45,30 @@ struct { QemuThread thread; } *vcpu_dirty_rate_stat; +typedef struct VcpuDirtyLimitState { + int cpu_index; + bool enabled; + /* + * Quota dirty page rate, unit is MB/s + * zero if not enabled. + */ + uint64_t quota; +} VcpuDirtyLimitState; + +struct { + VcpuDirtyLimitState *states; + /* Max cpus number configured by user */ + int max_cpus; + /* Number of vcpu under dirtylimit */ + int limited_nvcpu; +} *dirtylimit_state; + +/* protect dirtylimit_state */ +static QemuMutex dirtylimit_mutex; + +/* dirtylimit thread quit if dirtylimit_quit is true */ +static bool dirtylimit_quit; + static void vcpu_dirty_rate_stat_collect(void) { VcpuStat stat; @@ -54,6 +98,9 @@ static void *vcpu_dirty_rate_stat_thread(void *opaque) while (qatomic_read(&vcpu_dirty_rate_stat->running)) { vcpu_dirty_rate_stat_collect(); + if (dirtylimit_in_service()) { + dirtylimit_process(); + } } /* stop log sync */ @@ -86,9 +133,11 @@ void vcpu_dirty_rate_stat_start(void) void vcpu_dirty_rate_stat_stop(void) { qatomic_set(&vcpu_dirty_rate_stat->running, 0); + dirtylimit_state_unlock(); qemu_mutex_unlock_iothread(); qemu_thread_join(&vcpu_dirty_rate_stat->thread); qemu_mutex_lock_iothread(); + dirtylimit_state_lock(); } void vcpu_dirty_rate_stat_initialize(void) @@ -114,3 +163,245 @@ void vcpu_dirty_rate_stat_finalize(void) free(vcpu_dirty_rate_stat); vcpu_dirty_rate_stat = NULL; } + +void dirtylimit_state_lock(void) +{ + qemu_mutex_lock(&dirtylimit_mutex); +} + +void dirtylimit_state_unlock(void) +{ + qemu_mutex_unlock(&dirtylimit_mutex); +} + +static void +__attribute__((__constructor__)) dirtylimit_mutex_init(void) +{ + qemu_mutex_init(&dirtylimit_mutex); +} + +static inline VcpuDirtyLimitState *dirtylimit_vcpu_get_state(int cpu_index) +{ + return &dirtylimit_state->states[cpu_index]; +} + +void dirtylimit_state_initialize(void) +{ + MachineState *ms = MACHINE(qdev_get_machine()); + int max_cpus = ms->smp.max_cpus; + int i; + + dirtylimit_state = g_malloc0(sizeof(*dirtylimit_state)); + + dirtylimit_state->states = + g_malloc0(sizeof(VcpuDirtyLimitState) * max_cpus); + + for (i = 0; i < max_cpus; i++) { + dirtylimit_state->states[i].cpu_index = i; + } + + dirtylimit_state->max_cpus = max_cpus; + trace_dirtylimit_state_initialize(max_cpus); +} + +void dirtylimit_state_finalize(void) +{ + free(dirtylimit_state->states); + dirtylimit_state->states = NULL; + + free(dirtylimit_state); + dirtylimit_state = NULL; + + trace_dirtylimit_state_finalize(); +} + +bool dirtylimit_in_service(void) +{ + return !!dirtylimit_state; +} + +bool dirtylimit_vcpu_index_valid(int cpu_index) +{ + MachineState *ms = MACHINE(qdev_get_machine()); + + return !(cpu_index < 0 || + cpu_index >= ms->smp.max_cpus); +} + +static inline int64_t dirtylimit_dirty_ring_full_time(uint64_t dirtyrate) +{ + static uint64_t max_dirtyrate; + uint32_t dirty_ring_size = kvm_dirty_ring_size(); + uint64_t dirty_ring_size_meory_MB = + dirty_ring_size * TARGET_PAGE_SIZE >> 20; + + if (max_dirtyrate < dirtyrate) { + max_dirtyrate = dirtyrate; + } + + return dirty_ring_size_meory_MB * 1000000 / max_dirtyrate; +} + +static inline bool dirtylimit_done(uint64_t quota, + uint64_t current) +{ + uint64_t min, max; + + min = MIN(quota, current); + max = MAX(quota, current); + + return ((max - min) <= DIRTYLIMIT_TOLERANCE_RANGE) ? true : false; +} + +static inline bool +dirtylimit_need_linear_adjustment(uint64_t quota, + uint64_t current) +{ + uint64_t min, max; + + min = MIN(quota, current); + max = MAX(quota, current); + + return ((max - min) * 100 / max) > DIRTYLIMIT_LINEAR_ADJUSTMENT_PCT; +} + +static void dirtylimit_set_throttle(CPUState *cpu, + uint64_t quota, + uint64_t current) +{ + int64_t ring_full_time_us = 0; + uint64_t sleep_pct = 0; + uint64_t throttle_us = 0; + + if (current == 0) { + cpu->throttle_us_per_full = 0; + return; + } + + ring_full_time_us = dirtylimit_dirty_ring_full_time(current); + + if (dirtylimit_need_linear_adjustment(quota, current)) { + if (quota < current) { + sleep_pct = (current - quota) * 100 / current; + throttle_us = + ring_full_time_us * sleep_pct / (double)(100 - sleep_pct); + cpu->throttle_us_per_full += throttle_us; + } else { + sleep_pct = (quota - current) * 100 / quota; + throttle_us = + ring_full_time_us * sleep_pct / (double)(100 - sleep_pct); + cpu->throttle_us_per_full -= throttle_us; + } + + trace_dirtylimit_throttle_pct(cpu->cpu_index, + sleep_pct, + throttle_us); + } else { + if (quota < current) { + cpu->throttle_us_per_full += ring_full_time_us / 10; + } else { + cpu->throttle_us_per_full -= ring_full_time_us / 10; + } + } + + /* + * TODO: in the big kvm_dirty_ring_size case (eg: 65536, or other scenario), + * current dirty page rate may never reach the quota, we should stop + * increasing sleep time? + */ + cpu->throttle_us_per_full = MIN(cpu->throttle_us_per_full, + ring_full_time_us * DIRTYLIMIT_THROTTLE_PCT_MAX); + + cpu->throttle_us_per_full = MAX(cpu->throttle_us_per_full, 0); +} + +static void dirtylimit_adjust_throttle(CPUState *cpu) +{ + uint64_t quota = 0; + uint64_t current = 0; + int cpu_index = cpu->cpu_index; + + quota = dirtylimit_vcpu_get_state(cpu_index)->quota; + current = vcpu_dirty_rate_get(cpu_index); + + if (!dirtylimit_done(quota, current)) { + dirtylimit_set_throttle(cpu, quota, current); + } + + return; +} + +void dirtylimit_process(void) +{ + CPUState *cpu; + + if (!qatomic_read(&dirtylimit_quit)) { + dirtylimit_state_lock(); + + if (!dirtylimit_in_service()) { + dirtylimit_state_unlock(); + return; + } + + CPU_FOREACH(cpu) { + if (!dirtylimit_vcpu_get_state(cpu->cpu_index)->enabled) { + continue; + } + dirtylimit_adjust_throttle(cpu); + } + dirtylimit_state_unlock(); + } +} + +void dirtylimit_change(bool start) +{ + if (start) { + qatomic_set(&dirtylimit_quit, 0); + } else { + qatomic_set(&dirtylimit_quit, 1); + } +} + +void dirtylimit_set_vcpu(int cpu_index, + uint64_t quota, + bool enable) +{ + trace_dirtylimit_set_vcpu(cpu_index, quota); + + if (enable) { + dirtylimit_state->states[cpu_index].quota = quota; + if (!dirtylimit_vcpu_get_state(cpu_index)->enabled) { + dirtylimit_state->limited_nvcpu++; + } + } else { + dirtylimit_state->states[cpu_index].quota = 0; + if (dirtylimit_state->states[cpu_index].enabled) { + dirtylimit_state->limited_nvcpu--; + } + } + + dirtylimit_state->states[cpu_index].enabled = enable; +} + +void dirtylimit_set_all(uint64_t quota, + bool enable) +{ + MachineState *ms = MACHINE(qdev_get_machine()); + int max_cpus = ms->smp.max_cpus; + int i; + + for (i = 0; i < max_cpus; i++) { + dirtylimit_set_vcpu(i, quota, enable); + } +} + +void dirtylimit_vcpu_execute(CPUState *cpu) +{ + if (dirtylimit_in_service() && + dirtylimit_vcpu_get_state(cpu->cpu_index)->enabled && + cpu->throttle_us_per_full) { + trace_dirtylimit_vcpu_execute(cpu->cpu_index, + cpu->throttle_us_per_full); + usleep(cpu->throttle_us_per_full); + } +} |