Re: [Qemu-devel] [PATCH 21/22] Add XBZRLE statistics

[Luiz Capitulino]

On Fri, 13 Jul 2012 09:23:43 +0200
Juan Quintela <address@hidden> wrote:

> From: Orit Wasserman <address@hidden>
> 
> Signed-off-by: Benoit Hudzia <address@hidden>
> Signed-off-by: Petter Svard <address@hidden>
> Signed-off-by: Aidan Shribman <address@hidden>
> Signed-off-by: Orit Wasserman <address@hidden>
> Signed-off-by: Juan Quintela <address@hidden>
> ---
>  arch_init.c      |   66 
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  hmp.c            |   13 +++++++++++
>  migration.c      |   49 ++++++++++++++++++++++++++++++++++++++++
>  migration.h      |    9 ++++++++
>  qapi-schema.json |   37 +++++++++++++++++++++++++-----
>  qmp-commands.hx  |   35 ++++++++++++++++++++++++++++-
>  6 files changed, 203 insertions(+), 6 deletions(-)
> 
> diff --git a/arch_init.c b/arch_init.c
> index d972d84..ab3fb2c 100644
> --- a/arch_init.c
> +++ b/arch_init.c
> @@ -202,6 +202,64 @@ int64_t xbzrle_cache_resize(int64_t new_size)
>      return pow2floor(new_size);
>  }
> 
> +/* accounting for migration statistics */
> +typedef struct AccountingInfo {
> +    uint64_t dup_pages;
> +    uint64_t norm_pages;
> +    uint64_t xbzrle_bytes;
> +    uint64_t xbzrle_pages;
> +    uint64_t xbzrle_cache_miss;
> +    uint64_t iterations;
> +    uint64_t xbzrle_overflows;
> +} AccountingInfo;
> +
> +static AccountingInfo acct_info;
> +
> +static void acct_clear(void)
> +{
> +    memset(&acct_info, 0, sizeof(acct_info));
> +}
> +
> +uint64_t dup_mig_bytes_transferred(void)
> +{
> +    return acct_info.dup_pages * TARGET_PAGE_SIZE;
> +}
> +
> +uint64_t dup_mig_pages_transferred(void)
> +{
> +    return acct_info.dup_pages;
> +}
> +
> +uint64_t norm_mig_bytes_transferred(void)
> +{
> +    return acct_info.norm_pages * TARGET_PAGE_SIZE;
> +}
> +
> +uint64_t norm_mig_pages_transferred(void)
> +{
> +    return acct_info.norm_pages;
> +}
> +
> +uint64_t xbzrle_mig_bytes_transferred(void)
> +{
> +    return acct_info.xbzrle_bytes;
> +}
> +
> +uint64_t xbzrle_mig_pages_transferred(void)
> +{
> +    return acct_info.xbzrle_pages;
> +}
> +
> +uint64_t xbzrle_mig_pages_cache_miss(void)
> +{
> +    return acct_info.xbzrle_cache_miss;
> +}
> +
> +uint64_t xbzrle_mig_pages_overflow(void)
> +{
> +    return acct_info.xbzrle_overflows;
> +}
> +
>  static void save_block_hdr(QEMUFile *f, RAMBlock *block, ram_addr_t offset,
>          int cont, int flag)
>  {
> @@ -230,6 +288,7 @@ static int save_xbzrle_page(QEMUFile *f, uint8_t 
> *current_data,
>      if (!cache_is_cached(XBZRLE.cache, current_addr)) {
>          cache_insert(XBZRLE.cache, current_addr,
>                       g_memdup(current_data, TARGET_PAGE_SIZE));
> +        acct_info.xbzrle_cache_miss++;
>          return -1;
>      }
> 
> @@ -244,6 +303,7 @@ static int save_xbzrle_page(QEMUFile *f, uint8_t 
> *current_data,
>          return 0;
>      } else if (encoded_len == -1) {
>          DPRINTF("Overflow\n");
> +        acct_info.xbzrle_overflows++;
>          /* update data in the cache */
>          memcpy(prev_cached_page, current_data, TARGET_PAGE_SIZE);
>          return -1;
> @@ -263,7 +323,9 @@ static int save_xbzrle_page(QEMUFile *f, uint8_t 
> *current_data,
>      qemu_put_byte(f, hdr.xh_flags);
>      qemu_put_be16(f, hdr.xh_len);
>      qemu_put_buffer(f, XBZRLE.encoded_buf, encoded_len);
> +    acct_info.xbzrle_pages++;
>      bytes_sent = encoded_len + sizeof(hdr);
> +    acct_info.xbzrle_bytes += bytes_sent;
> 
>      return bytes_sent;
>  }
> @@ -303,6 +365,7 @@ static int ram_save_block(QEMUFile *f)
>              p = memory_region_get_ram_ptr(mr) + offset;
> 
>              if (is_dup_page(p)) {
> +                acct_info.dup_pages++;
>                  save_block_hdr(f, block, offset, cont, 
> RAM_SAVE_FLAG_COMPRESS);
>                  qemu_put_byte(f, *p);
>                  bytes_sent = 1;
> @@ -318,6 +381,7 @@ static int ram_save_block(QEMUFile *f)
>                  save_block_hdr(f, block, offset, cont, RAM_SAVE_FLAG_PAGE);
>                  qemu_put_buffer(f, p, TARGET_PAGE_SIZE);
>                  bytes_sent = TARGET_PAGE_SIZE;
> +                acct_info.norm_pages++;
>              }
> 
>              /* if page is unmodified, continue to the next */
> @@ -437,6 +501,7 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
>              return -1;
>          }
>          XBZRLE.encoded_buf = g_malloc0(TARGET_PAGE_SIZE);
> +        acct_clear();
>      }
> 
>      QLIST_FOREACH(block, &ram_list.blocks, next) {
> @@ -484,6 +549,7 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
>              break;
>          }
>          bytes_transferred += bytes_sent;
> +        acct_info.iterations++;
>          /* we want to check in the 1st loop, just in case it was the 1st time
>             and we had to sync the dirty bitmap.
>             qemu_get_clock_ns() is a bit expensive, so we only check each some
> diff --git a/hmp.c b/hmp.c
> index 99ad00a..0d7333b 100644
> --- a/hmp.c
> +++ b/hmp.c
> @@ -168,6 +168,19 @@ void hmp_info_migrate(Monitor *mon)
>                         info->disk->total >> 10);
>      }
> 
> +    if (info->has_cache) {
> +        monitor_printf(mon, "cache size: %" PRIu64 " bytes\n",
> +                       info->cache->cache_size);
> +        monitor_printf(mon, "xbzrle transferred: %" PRIu64 " kbytes\n",
> +                       info->cache->xbzrle_bytes >> 10);
> +        monitor_printf(mon, "xbzrle pages: %" PRIu64 " pages\n",
> +                       info->cache->xbzrle_pages);
> +        monitor_printf(mon, "xbzrle cache miss: %" PRIu64 "\n",
> +                       info->cache->xbzrle_cache_miss);
> +        monitor_printf(mon, "xbzrle overflow : %" PRIu64 "\n",
> +                       info->cache->xbzrle_overflow);
> +    }
> +
>      qapi_free_MigrationInfo(info);
>  }
> 
> diff --git a/migration.c b/migration.c
> index d134bf6..e11f451 100644
> --- a/migration.c
> +++ b/migration.c
> @@ -137,6 +137,17 @@ MigrationInfo *qmp_query_migrate(Error **errp)
>              info->capabilities->value->state = s->enabled_capabilities[i];
>              info->capabilities->next = NULL;
>          }
> +
> +        /* display xbzrle cache size */
> +        if (migrate_use_xbzrle()) {
> +            info->has_cache = true;
> +            info->cache = g_malloc0(sizeof(*info->cache));
> +            info->cache->cache_size = migrate_xbzrle_cache_size();
> +            info->cache->xbzrle_bytes = xbzrle_mig_bytes_transferred();
> +            info->cache->xbzrle_pages = xbzrle_mig_pages_transferred();
> +            info->cache->xbzrle_cache_miss = xbzrle_mig_pages_cache_miss();
> +            info->cache->xbzrle_overflow = xbzrle_mig_pages_overflow();
> +        }

Why do you need this in MIG_STATE_SETUP? I think having it only in
MIG_STATE_ACTIVE is enough (and probably that's what we want).

>          break;
>      case MIG_STATE_ACTIVE:
>          for (i = 0; i < MIGRATION_CAPABILITY_MAX; i++) {
> @@ -161,6 +172,8 @@ MigrationInfo *qmp_query_migrate(Error **errp)
>          info->ram->total = ram_bytes_total();
>          info->ram->total_time = qemu_get_clock_ms(rt_clock)
>              - s->total_time;
> +        info->ram->duplicate = dup_mig_pages_transferred();
> +        info->ram->normal = norm_mig_pages_transferred();

Can we do this extension in a different patch?

> 
>          if (blk_mig_active()) {
>              info->has_disk = true;
> @@ -169,6 +182,16 @@ MigrationInfo *qmp_query_migrate(Error **errp)
>              info->disk->remaining = blk_mig_bytes_remaining();
>              info->disk->total = blk_mig_bytes_total();
>          }
> +
> +        if (migrate_use_xbzrle()) {
> +            info->has_cache = true;
> +            info->cache = g_malloc0(sizeof(*info->cache));
> +            info->cache->cache_size = migrate_xbzrle_cache_size();
> +            info->cache->xbzrle_bytes = xbzrle_mig_bytes_transferred();
> +            info->cache->xbzrle_pages = xbzrle_mig_pages_transferred();
> +            info->cache->xbzrle_cache_miss = xbzrle_mig_pages_cache_miss();
> +            info->cache->xbzrle_overflow = xbzrle_mig_pages_overflow();
> +        }
>          break;
>      case MIG_STATE_COMPLETED:
>          for (i = 0; i < MIGRATION_CAPABILITY_MAX; i++) {
> @@ -183,6 +206,32 @@ MigrationInfo *qmp_query_migrate(Error **errp)
>              info->capabilities->next = NULL;
>          }
> 
> +        info->has_ram = true;
> +        info->ram = g_malloc0(sizeof(*info->ram));
> +        info->ram->transferred = ram_bytes_transferred();
> +        info->ram->remaining = ram_bytes_remaining();
> +        info->ram->total = ram_bytes_total();
> +        info->ram->duplicate = dup_mig_pages_transferred();
> +        info->ram->normal = norm_mig_pages_transferred();

This hunk is probably bad copy & paste, as this code already exists.

> +
> +        if (blk_mig_active()) {
> +            info->has_disk = true;
> +            info->disk = g_malloc0(sizeof(*info->disk));
> +            info->disk->transferred = blk_mig_bytes_transferred();
> +            info->disk->remaining = blk_mig_bytes_remaining();
> +            info->disk->total = blk_mig_bytes_total();
> +        }

Why are you doing this, bad copy & paste too?

> +
> +        if (migrate_use_xbzrle()) {
> +            info->has_cache = true;
> +            info->cache = g_malloc0(sizeof(*info->cache));
> +            info->cache->cache_size = migrate_xbzrle_cache_size();
> +            info->cache->xbzrle_bytes = xbzrle_mig_bytes_transferred();
> +            info->cache->xbzrle_pages = xbzrle_mig_pages_transferred();
> +            info->cache->xbzrle_cache_miss = xbzrle_mig_pages_cache_miss();
> +            info->cache->xbzrle_overflow = xbzrle_mig_pages_overflow();
> +        }
> +
>          info->has_status = true;
>          info->status = g_strdup("completed");
> 
> diff --git a/migration.h b/migration.h
> index 337e225..a9852fc 100644
> --- a/migration.h
> +++ b/migration.h
> @@ -87,6 +87,15 @@ uint64_t ram_bytes_total(void);
> 
>  extern SaveVMHandlers savevm_ram_handlers;
> 
> +uint64_t dup_mig_bytes_transferred(void);
> +uint64_t dup_mig_pages_transferred(void);
> +uint64_t norm_mig_bytes_transferred(void);
> +uint64_t norm_mig_pages_transferred(void);
> +uint64_t xbzrle_mig_bytes_transferred(void);
> +uint64_t xbzrle_mig_pages_transferred(void);
> +uint64_t xbzrle_mig_pages_overflow(void);
> +uint64_t xbzrle_mig_pages_cache_miss(void);
> +
>  /**
>   * @migrate_add_blocker - prevent migration from proceeding
>   *
> diff --git a/qapi-schema.json b/qapi-schema.json
> index a0f0f95..961810b 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -264,11 +264,35 @@
>  #        migration has ended, it returns the total migration
>  #        time. (since 1.2)
>  #
> -# Since: 0.14.0.
> +# @duplicate: #optional, number of duplicate pages
> +#
> +# @normal : #optional, number of normal pages
> +#
> +# Since: 0.14.0, 'duplicate' and 'normal' since 1.2

Please, put 'since' in the same line of the field, like this:

 @normal : #optional, number of normal pages (since 1.2)

>  ##
>  { 'type': 'MigrationStats',
>    'data': {'transferred': 'int', 'remaining': 'int', 'total': 'int' ,
> -           'total_time': 'int' } }
> +           'total_time': 'int', '*duplicate': 'int', '*normal': 'int' } }
> +##
> +# @CacheStats

This is specific to xbzrle, right? So this should be called XBZRLECacheStats,
or something.

> +#
> +# Detailed XBZRLE migration cache statistics
> +#
> +# @cache_size: XBZRLE cache size
> +#
> +# @xbzrle_bytes: amount of bytes already transferred to the target VM
> +#
> +# @xbzrle_pages: amount of pages transferred to the target VM
> +#
> +# @xbzrle_cache_miss: number of cache miss
> +#
> +# @xbzrle_overflow: number of overflows
> +#
> +# Since: 1.2
> +##
> +{ 'type': 'CacheStats',
> +  'data': {'cache-size': 'int', 'xbzrle-bytes': 'int', 'xbzrle-pages': 'int',
> +           'xbzrle-cache-miss': 'int', 'xbzrle-overflow': 'int' } }
> 
>  ##
>  # @MigrationInfo
> @@ -291,13 +315,16 @@
>  # @capabilities: #optional a list describing all the migration capabilities
>  #                state
>  #
> -# Since: 0.14.0, 'capabilities' since 1.2
> +# @cache: #optional @MigrationStats containing detailed XBZRLE migration
> +#         statistics

xbzrle-cache.

> +#
> +# Since: 0.14.0, 'capabilities' and 'cache' since 1.2
>  ##
>  { 'type': 'MigrationInfo',
>    'data': {'*status': 'str', '*ram': 'MigrationStats',
>             '*disk': 'MigrationStats',
> -           '*capabilities': ['MigrationCapabilityInfo']} }
> -
> +           '*capabilities': ['MigrationCapabilityInfo'],
> +           '*cache': 'CacheStats'} }
>  ##
>  # @query-migrate
>  #
> diff --git a/qmp-commands.hx b/qmp-commands.hx
> index a3d57ce..34d4675 100644
> --- a/qmp-commands.hx
> +++ b/qmp-commands.hx
> @@ -2093,6 +2093,8 @@ The main json-object contains the following:
>           - "transferred": amount transferred (json-int)
>           - "remaining": amount remaining (json-int)
>           - "total": total (json-int)
> +      - "duplicate": number of duplicated pages (json-int)
> +      - "normal" : number of normal pages transferred (json-int)
>  - "disk": only present if "status" is "active" and it is a block migration,
>    it is a json-object with the following disk information (in bytes):
>           - "transferred": amount transferred (json-int)
> @@ -2100,10 +2102,17 @@ The main json-object contains the following:
>           - "total": total (json-int)
>  - "capabilities": migration capabilities state
>           - "xbzrle" : XBZRLE state (json-bool)
> +- "cache": only present if "status" and XBZRLE is active.
> +  It is a json-object with the following XBZRLE information:
> +         - "cache-size": XBZRLE cache size
> +         - "xbzrle-bytes": total XBZRLE bytes transferred
> +         - "xbzrle-pages": number of XBZRLE compressed pages
> +         - "cache-miss": number of cache misses
> +         - "overflow": number of XBZRLE overflows
> +
>  Examples:
> 
>  1. Before the first migration
> -
>  -> { "execute": "query-migrate" }
>  <- { "return": {
>          "capabilities" :  [ { "capability" : "xbzrle", "state" : false } ]
> @@ -2164,6 +2173,30 @@ Examples:
>        }
>     }
> 
> +6. Migration is being performed and XBZRLE is active:
> +
> +-> { "execute": "query-migrate" }
> +<- {
> +      "return":{
> +         "status":"active",
> +         "capabilities" : [ { "capability": "xbzrle", "state" : true } ],
> +         "ram":{
> +            "total":1057024,
> +            "remaining":1053304,
> +            "transferred":3720,
> +            "duplicate": 10,
> +            "normal" : 3333
> +         },
> +         "cache":{
> +            "cache-size": 1024
> +            "xbzrle-transferred":20971520,
> +            "xbzrle-pages":2444343,
> +            "xbzrle-cache-miss":2244,
> +            "xbzrle-overflow":34434
> +         }
> +      }
> +   }
> +
>  EQMP
> 
>      {