diff options
| -rw-r--r-- | migration/migration.c | 1 | ||||
| -rw-r--r-- | migration/ram.c | 39 | ||||
| -rw-r--r-- | monitor/hmp-cmds.c | 2 | ||||
| -rw-r--r-- | qapi/migration.json | 5 |
4 files changed, 44 insertions, 3 deletions
diff --git a/migration/migration.c b/migration/migration.c index f5dbffc..0bb042a 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -932,6 +932,7 @@ static void populate_ram_info(MigrationInfo *info, MigrationState *s) info->xbzrle_cache->pages = xbzrle_counters.pages; info->xbzrle_cache->cache_miss = xbzrle_counters.cache_miss; info->xbzrle_cache->cache_miss_rate = xbzrle_counters.cache_miss_rate; + info->xbzrle_cache->encoding_rate = xbzrle_counters.encoding_rate; info->xbzrle_cache->overflow = xbzrle_counters.overflow; } diff --git a/migration/ram.c b/migration/ram.c index 08eb382..859f835 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -327,6 +327,10 @@ struct RAMState { uint64_t num_dirty_pages_period; /* xbzrle misses since the beginning of the period */ uint64_t xbzrle_cache_miss_prev; + /* Amount of xbzrle pages since the beginning of the period */ + uint64_t xbzrle_pages_prev; + /* Amount of xbzrle encoded bytes since the beginning of the period */ + uint64_t xbzrle_bytes_prev; /* compression statistics since the beginning of the period */ /* amount of count that no free thread to compress data */ @@ -710,6 +714,18 @@ static int save_xbzrle_page(RAMState *rs, uint8_t **current_data, return -1; } + /* + * Reaching here means the page has hit the xbzrle cache, no matter what + * encoding result it is (normal encoding, overflow or skipping the page), + * count the page as encoded. This is used to caculate the encoding rate. + * + * Example: 2 pages (8KB) being encoded, first page encoding generates 2KB, + * 2nd page turns out to be skipped (i.e. no new bytes written to the + * page), the overall encoding rate will be 8KB / 2KB = 4, which has the + * skipped page included. In this way, the encoding rate can tell if the + * guest page is good for xbzrle encoding. + */ + xbzrle_counters.pages++; prev_cached_page = get_cached_data(XBZRLE.cache, current_addr); /* save current buffer into memory */ @@ -740,6 +756,7 @@ static int save_xbzrle_page(RAMState *rs, uint8_t **current_data, } else if (encoded_len == -1) { trace_save_xbzrle_page_overflow(); xbzrle_counters.overflow++; + xbzrle_counters.bytes += TARGET_PAGE_SIZE; return -1; } @@ -750,8 +767,12 @@ static int save_xbzrle_page(RAMState *rs, uint8_t **current_data, qemu_put_be16(rs->f, encoded_len); qemu_put_buffer(rs->f, XBZRLE.encoded_buf, encoded_len); bytes_xbzrle += encoded_len + 1 + 2; - xbzrle_counters.pages++; - xbzrle_counters.bytes += bytes_xbzrle; + /* + * Like compressed_size (please see update_compress_thread_counts), + * the xbzrle encoded bytes don't count the 8 byte header with + * RAM_SAVE_FLAG_CONTINUE. + */ + xbzrle_counters.bytes += bytes_xbzrle - 8; ram_counters.transferred += bytes_xbzrle; return 1; @@ -884,9 +905,23 @@ static void migration_update_rates(RAMState *rs, int64_t end_time) } if (migrate_use_xbzrle()) { + double encoded_size, unencoded_size; + xbzrle_counters.cache_miss_rate = (double)(xbzrle_counters.cache_miss - rs->xbzrle_cache_miss_prev) / page_count; rs->xbzrle_cache_miss_prev = xbzrle_counters.cache_miss; + unencoded_size = (xbzrle_counters.pages - rs->xbzrle_pages_prev) * + TARGET_PAGE_SIZE; + encoded_size = xbzrle_counters.bytes - rs->xbzrle_bytes_prev; + if (xbzrle_counters.pages == rs->xbzrle_pages_prev) { + xbzrle_counters.encoding_rate = 0; + } else if (!encoded_size) { + xbzrle_counters.encoding_rate = UINT64_MAX; + } else { + xbzrle_counters.encoding_rate = unencoded_size / encoded_size; + } + rs->xbzrle_pages_prev = xbzrle_counters.pages; + rs->xbzrle_bytes_prev = xbzrle_counters.bytes; } if (migrate_use_compression()) { diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c index ade1f85..9c61e76 100644 --- a/monitor/hmp-cmds.c +++ b/monitor/hmp-cmds.c @@ -303,6 +303,8 @@ void hmp_info_migrate(Monitor *mon, const QDict *qdict) info->xbzrle_cache->cache_miss); monitor_printf(mon, "xbzrle cache miss rate: %0.2f\n", info->xbzrle_cache->cache_miss_rate); + monitor_printf(mon, "xbzrle encoding rate: %0.2f\n", + info->xbzrle_cache->encoding_rate); monitor_printf(mon, "xbzrle overflow: %" PRIu64 "\n", info->xbzrle_cache->overflow); } diff --git a/qapi/migration.json b/qapi/migration.json index ee6c5a0..d500055 100644 --- a/qapi/migration.json +++ b/qapi/migration.json @@ -70,6 +70,8 @@ # # @cache-miss-rate: rate of cache miss (since 2.1) # +# @encoding-rate: rate of encoded bytes (since 5.1) +# # @overflow: number of overflows # # Since: 1.2 @@ -77,7 +79,7 @@ { 'struct': 'XBZRLECacheStats', 'data': {'cache-size': 'int', 'bytes': 'int', 'pages': 'int', 'cache-miss': 'int', 'cache-miss-rate': 'number', - 'overflow': 'int' } } + 'encoding-rate': 'number', 'overflow': 'int' } } ## # @CompressionStats: @@ -337,6 +339,7 @@ # "pages":2444343, # "cache-miss":2244, # "cache-miss-rate":0.123, +# "encoding-rate":80.1, # "overflow":34434 # } # } |