diff options
Diffstat (limited to 'migration/ram.c')
| -rw-r--r-- | migration/ram.c | 123 |
1 files changed, 82 insertions, 41 deletions
diff --git a/migration/ram.c b/migration/ram.c index 0ef68798d2..c12cfdbe26 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -896,11 +896,38 @@ static void migration_update_rates(RAMState *rs, int64_t end_time) } } +static void migration_trigger_throttle(RAMState *rs) +{ + MigrationState *s = migrate_get_current(); + uint64_t threshold = s->parameters.throttle_trigger_threshold; + + uint64_t bytes_xfer_period = ram_counters.transferred - rs->bytes_xfer_prev; + uint64_t bytes_dirty_period = rs->num_dirty_pages_period * TARGET_PAGE_SIZE; + uint64_t bytes_dirty_threshold = bytes_xfer_period * threshold / 100; + + /* During block migration the auto-converge logic incorrectly detects + * that ram migration makes no progress. Avoid this by disabling the + * throttling logic during the bulk phase of block migration. */ + if (migrate_auto_converge() && !blk_mig_bulk_active()) { + /* The following detection logic can be refined later. For now: + Check to see if the ratio between dirtied bytes and the approx. + amount of bytes that just got transferred since the last time + we were in this routine reaches the threshold. If that happens + twice, start or increase throttling. */ + + if ((bytes_dirty_period > bytes_dirty_threshold) && + (++rs->dirty_rate_high_cnt >= 2)) { + trace_migration_throttle(); + rs->dirty_rate_high_cnt = 0; + mig_throttle_guest_down(); + } + } +} + static void migration_bitmap_sync(RAMState *rs) { RAMBlock *block; int64_t end_time; - uint64_t bytes_xfer_now; ram_counters.dirty_sync_count++; @@ -927,26 +954,7 @@ static void migration_bitmap_sync(RAMState *rs) /* more than 1 second = 1000 millisecons */ if (end_time > rs->time_last_bitmap_sync + 1000) { - bytes_xfer_now = ram_counters.transferred; - - /* During block migration the auto-converge logic incorrectly detects - * that ram migration makes no progress. Avoid this by disabling the - * throttling logic during the bulk phase of block migration. */ - if (migrate_auto_converge() && !blk_mig_bulk_active()) { - /* The following detection logic can be refined later. For now: - Check to see if the dirtied bytes is 50% more than the approx. - amount of bytes that just got transferred since the last time we - were in this routine. If that happens twice, start or increase - throttling */ - - if ((rs->num_dirty_pages_period * TARGET_PAGE_SIZE > - (bytes_xfer_now - rs->bytes_xfer_prev) / 2) && - (++rs->dirty_rate_high_cnt >= 2)) { - trace_migration_throttle(); - rs->dirty_rate_high_cnt = 0; - mig_throttle_guest_down(); - } - } + migration_trigger_throttle(rs); migration_update_rates(rs, end_time); @@ -955,7 +963,7 @@ static void migration_bitmap_sync(RAMState *rs) /* reset period counters */ rs->time_last_bitmap_sync = end_time; rs->num_dirty_pages_period = 0; - rs->bytes_xfer_prev = bytes_xfer_now; + rs->bytes_xfer_prev = ram_counters.transferred; } if (migrate_use_events()) { qapi_event_send_migration_pass(ram_counters.dirty_sync_count); @@ -2734,7 +2742,7 @@ static inline void *host_from_ram_block_offset(RAMBlock *block, } static inline void *colo_cache_from_block_offset(RAMBlock *block, - ram_addr_t offset) + ram_addr_t offset, bool record_bitmap) { if (!offset_in_ramblock(block, offset)) { return NULL; @@ -2750,7 +2758,8 @@ static inline void *colo_cache_from_block_offset(RAMBlock *block, * It help us to decide which pages in ram cache should be flushed * into VM's RAM later. */ - if (!test_and_set_bit(offset >> TARGET_PAGE_BITS, block->bmap)) { + if (record_bitmap && + !test_and_set_bit(offset >> TARGET_PAGE_BITS, block->bmap)) { ram_state->migration_dirty_pages++; } return block->colo_cache + offset; @@ -2986,7 +2995,6 @@ int colo_init_ram_cache(void) } return -errno; } - memcpy(block->colo_cache, block->host, block->used_length); } } @@ -3000,19 +3008,36 @@ int colo_init_ram_cache(void) RAMBLOCK_FOREACH_NOT_IGNORED(block) { unsigned long pages = block->max_length >> TARGET_PAGE_BITS; - block->bmap = bitmap_new(pages); - bitmap_set(block->bmap, 0, pages); } } - ram_state = g_new0(RAMState, 1); - ram_state->migration_dirty_pages = 0; - qemu_mutex_init(&ram_state->bitmap_mutex); - memory_global_dirty_log_start(); + ram_state_init(&ram_state); return 0; } +/* TODO: duplicated with ram_init_bitmaps */ +void colo_incoming_start_dirty_log(void) +{ + RAMBlock *block = NULL; + /* For memory_global_dirty_log_start below. */ + qemu_mutex_lock_iothread(); + qemu_mutex_lock_ramlist(); + + memory_global_dirty_log_sync(); + WITH_RCU_READ_LOCK_GUARD() { + RAMBLOCK_FOREACH_NOT_IGNORED(block) { + ramblock_sync_dirty_bitmap(ram_state, block); + /* Discard this dirty bitmap record */ + bitmap_zero(block->bmap, block->max_length >> TARGET_PAGE_BITS); + } + memory_global_dirty_log_start(); + } + ram_state->migration_dirty_pages = 0; + qemu_mutex_unlock_ramlist(); + qemu_mutex_unlock_iothread(); +} + /* It is need to hold the global lock to call this helper */ void colo_release_ram_cache(void) { @@ -3032,9 +3057,7 @@ void colo_release_ram_cache(void) } } } - qemu_mutex_destroy(&ram_state->bitmap_mutex); - g_free(ram_state); - ram_state = NULL; + ram_state_cleanup(&ram_state); } /** @@ -3348,7 +3371,7 @@ static int ram_load_precopy(QEMUFile *f) while (!ret && !(flags & RAM_SAVE_FLAG_EOS)) { ram_addr_t addr, total_ram_bytes; - void *host = NULL; + void *host = NULL, *host_bak = NULL; uint8_t ch; /* @@ -3379,20 +3402,35 @@ static int ram_load_precopy(QEMUFile *f) RAM_SAVE_FLAG_COMPRESS_PAGE | RAM_SAVE_FLAG_XBZRLE)) { RAMBlock *block = ram_block_from_stream(f, flags); + host = host_from_ram_block_offset(block, addr); /* - * After going into COLO, we should load the Page into colo_cache. + * After going into COLO stage, we should not load the page + * into SVM's memory directly, we put them into colo_cache firstly. + * NOTE: We need to keep a copy of SVM's ram in colo_cache. + * Previously, we copied all these memory in preparing stage of COLO + * while we need to stop VM, which is a time-consuming process. + * Here we optimize it by a trick, back-up every page while in + * migration process while COLO is enabled, though it affects the + * speed of the migration, but it obviously reduce the downtime of + * back-up all SVM'S memory in COLO preparing stage. */ - if (migration_incoming_in_colo_state()) { - host = colo_cache_from_block_offset(block, addr); - } else { - host = host_from_ram_block_offset(block, addr); + if (migration_incoming_colo_enabled()) { + if (migration_incoming_in_colo_state()) { + /* In COLO stage, put all pages into cache temporarily */ + host = colo_cache_from_block_offset(block, addr, true); + } else { + /* + * In migration stage but before COLO stage, + * Put all pages into both cache and SVM's memory. + */ + host_bak = colo_cache_from_block_offset(block, addr, false); + } } if (!host) { error_report("Illegal RAM offset " RAM_ADDR_FMT, addr); ret = -EINVAL; break; } - if (!migration_incoming_in_colo_state()) { ramblock_recv_bitmap_set(block, host); } @@ -3506,6 +3544,9 @@ static int ram_load_precopy(QEMUFile *f) if (!ret) { ret = qemu_file_get_error(f); } + if (!ret && host_bak) { + memcpy(host_bak, host, TARGET_PAGE_SIZE); + } } ret |= wait_for_decompress_done(); |