diff options
| -rw-r--r-- | migration/postcopy-ram.c | 151 | ||||
| -rw-r--r-- | migration/trace-events | 5 |
2 files changed, 154 insertions, 2 deletions
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index eddba05b57..6b34a7148e 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -636,6 +636,148 @@ int postcopy_request_shared_page(struct PostCopyFD *pcfd, RAMBlock *rb, return 0; } +static int get_mem_fault_cpu_index(uint32_t pid) +{ + CPUState *cpu_iter; + + CPU_FOREACH(cpu_iter) { + if (cpu_iter->thread_id == pid) { + trace_get_mem_fault_cpu_index(cpu_iter->cpu_index, pid); + return cpu_iter->cpu_index; + } + } + trace_get_mem_fault_cpu_index(-1, pid); + return -1; +} + +static uint32_t get_low_time_offset(PostcopyBlocktimeContext *dc) +{ + int64_t start_time_offset = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) - + dc->start_time; + return start_time_offset < 1 ? 1 : start_time_offset & UINT32_MAX; +} + +/* + * This function is being called when pagefault occurs. It + * tracks down vCPU blocking time. + * + * @addr: faulted host virtual address + * @ptid: faulted process thread id + * @rb: ramblock appropriate to addr + */ +static void mark_postcopy_blocktime_begin(uintptr_t addr, uint32_t ptid, + RAMBlock *rb) +{ + int cpu, already_received; + MigrationIncomingState *mis = migration_incoming_get_current(); + PostcopyBlocktimeContext *dc = mis->blocktime_ctx; + uint32_t low_time_offset; + + if (!dc || ptid == 0) { + return; + } + cpu = get_mem_fault_cpu_index(ptid); + if (cpu < 0) { + return; + } + + low_time_offset = get_low_time_offset(dc); + if (dc->vcpu_addr[cpu] == 0) { + atomic_inc(&dc->smp_cpus_down); + } + + atomic_xchg(&dc->last_begin, low_time_offset); + atomic_xchg(&dc->page_fault_vcpu_time[cpu], low_time_offset); + atomic_xchg(&dc->vcpu_addr[cpu], addr); + + /* check it here, not at the begining of the function, + * due to, check could accur early than bitmap_set in + * qemu_ufd_copy_ioctl */ + already_received = ramblock_recv_bitmap_test(rb, (void *)addr); + if (already_received) { + atomic_xchg(&dc->vcpu_addr[cpu], 0); + atomic_xchg(&dc->page_fault_vcpu_time[cpu], 0); + atomic_dec(&dc->smp_cpus_down); + } + trace_mark_postcopy_blocktime_begin(addr, dc, dc->page_fault_vcpu_time[cpu], + cpu, already_received); +} + +/* + * This function just provide calculated blocktime per cpu and trace it. + * Total blocktime is calculated in mark_postcopy_blocktime_end. + * + * + * Assume we have 3 CPU + * + * S1 E1 S1 E1 + * -----***********------------xxx***************------------------------> CPU1 + * + * S2 E2 + * ------------****************xxx---------------------------------------> CPU2 + * + * S3 E3 + * ------------------------****xxx********-------------------------------> CPU3 + * + * We have sequence S1,S2,E1,S3,S1,E2,E3,E1 + * S2,E1 - doesn't match condition due to sequence S1,S2,E1 doesn't include CPU3 + * S3,S1,E2 - sequence includes all CPUs, in this case overlap will be S1,E2 - + * it's a part of total blocktime. + * S1 - here is last_begin + * Legend of the picture is following: + * * - means blocktime per vCPU + * x - means overlapped blocktime (total blocktime) + * + * @addr: host virtual address + */ +static void mark_postcopy_blocktime_end(uintptr_t addr) +{ + MigrationIncomingState *mis = migration_incoming_get_current(); + PostcopyBlocktimeContext *dc = mis->blocktime_ctx; + int i, affected_cpu = 0; + bool vcpu_total_blocktime = false; + uint32_t read_vcpu_time, low_time_offset; + + if (!dc) { + return; + } + + low_time_offset = get_low_time_offset(dc); + /* lookup cpu, to clear it, + * that algorithm looks straighforward, but it's not + * optimal, more optimal algorithm is keeping tree or hash + * where key is address value is a list of */ + for (i = 0; i < smp_cpus; i++) { + uint32_t vcpu_blocktime = 0; + + read_vcpu_time = atomic_fetch_add(&dc->page_fault_vcpu_time[i], 0); + if (atomic_fetch_add(&dc->vcpu_addr[i], 0) != addr || + read_vcpu_time == 0) { + continue; + } + atomic_xchg(&dc->vcpu_addr[i], 0); + vcpu_blocktime = low_time_offset - read_vcpu_time; + affected_cpu += 1; + /* we need to know is that mark_postcopy_end was due to + * faulted page, another possible case it's prefetched + * page and in that case we shouldn't be here */ + if (!vcpu_total_blocktime && + atomic_fetch_add(&dc->smp_cpus_down, 0) == smp_cpus) { + vcpu_total_blocktime = true; + } + /* continue cycle, due to one page could affect several vCPUs */ + dc->vcpu_blocktime[i] += vcpu_blocktime; + } + + atomic_sub(&dc->smp_cpus_down, affected_cpu); + if (vcpu_total_blocktime) { + dc->total_blocktime += low_time_offset - atomic_fetch_add( + &dc->last_begin, 0); + } + trace_mark_postcopy_blocktime_end(addr, dc, dc->total_blocktime, + affected_cpu); +} + /* * Handle faults detected by the USERFAULT markings */ @@ -742,7 +884,12 @@ static void *postcopy_ram_fault_thread(void *opaque) rb_offset &= ~(qemu_ram_pagesize(rb) - 1); trace_postcopy_ram_fault_thread_request(msg.arg.pagefault.address, qemu_ram_get_idstr(rb), - rb_offset); + rb_offset, + msg.arg.pagefault.feat.ptid); + mark_postcopy_blocktime_begin( + (uintptr_t)(msg.arg.pagefault.address), + msg.arg.pagefault.feat.ptid, rb); + /* * Send the request to the source - we want to request one * of our host page sizes (which is >= TPS) @@ -890,6 +1037,8 @@ static int qemu_ufd_copy_ioctl(int userfault_fd, void *host_addr, if (!ret) { ramblock_recv_bitmap_set_range(rb, host_addr, pagesize / qemu_target_page_size()); + mark_postcopy_blocktime_end((uintptr_t)host_addr); + } return ret; } diff --git a/migration/trace-events b/migration/trace-events index a180d7b008..368bc4b663 100644 --- a/migration/trace-events +++ b/migration/trace-events @@ -115,6 +115,8 @@ process_incoming_migration_co_end(int ret, int ps) "ret=%d postcopy-state=%d" process_incoming_migration_co_postcopy_end_main(void) "" migration_set_incoming_channel(void *ioc, const char *ioctype) "ioc=%p ioctype=%s" migration_set_outgoing_channel(void *ioc, const char *ioctype, const char *hostname, void *err) "ioc=%p ioctype=%s hostname=%s err=%p" +mark_postcopy_blocktime_begin(uint64_t addr, void *dd, uint32_t time, int cpu, int received) "addr: 0x%" PRIx64 ", dd: %p, time: %u, cpu: %d, already_received: %d" +mark_postcopy_blocktime_end(uint64_t addr, void *dd, uint32_t time, int affected_cpu) "addr: 0x%" PRIx64 ", dd: %p, time: %u, affected_cpu: %d" # migration/rdma.c qemu_rdma_accept_incoming_migration(void) "" @@ -193,7 +195,7 @@ postcopy_ram_fault_thread_exit(void) "" postcopy_ram_fault_thread_fds_core(int baseufd, int quitfd) "ufd: %d quitfd: %d" postcopy_ram_fault_thread_fds_extra(size_t index, const char *name, int fd) "%zd/%s: %d" postcopy_ram_fault_thread_quit(void) "" -postcopy_ram_fault_thread_request(uint64_t hostaddr, const char *ramblock, size_t offset) "Request for HVA=0x%" PRIx64 " rb=%s offset=0x%zx" +postcopy_ram_fault_thread_request(uint64_t hostaddr, const char *ramblock, size_t offset, uint32_t pid) "Request for HVA=0x%" PRIx64 " rb=%s offset=0x%zx pid=%u" postcopy_ram_incoming_cleanup_closeuf(void) "" postcopy_ram_incoming_cleanup_entry(void) "" postcopy_ram_incoming_cleanup_exit(void) "" @@ -206,6 +208,7 @@ save_xbzrle_page_skipping(void) "" save_xbzrle_page_overflow(void) "" ram_save_iterate_big_wait(uint64_t milliconds, int iterations) "big wait: %" PRIu64 " milliseconds, %d iterations" ram_load_complete(int ret, uint64_t seq_iter) "exit_code %d seq iteration %" PRIu64 +get_mem_fault_cpu_index(int cpu, uint32_t pid) "cpu: %d, pid: %u" # migration/exec.c migration_exec_outgoing(const char *cmd) "cmd=%s" |