Re: [Qemu-devel] [PATCH 10/11] Add XBZRLE statistics

[Luiz Capitulino <lcapitulino@redhat.com>]

On Tue, 31 Jul 2012 17:13:46 +0300
Orit Wasserman <owasserm@redhat.com> wrote:

> On 07/31/2012 04:16 PM, Luiz Capitulino wrote:
> > On Tue, 31 Jul 2012 11:31:09 +0300
> > Orit Wasserman <owasserm@redhat.com> wrote:
> > 
> >> On 07/30/2012 10:37 PM, Luiz Capitulino wrote:
> >>> On Sun, 29 Jul 2012 12:43:02 +0300
> >>> Orit Wasserman <owasserm@redhat.com> wrote:
> >>>
> >>>> Signed-off-by: Benoit Hudzia <benoit.hudzia@sap.com>
> >>>> Signed-off-by: Petter Svard <petters@cs.umu.se>
> >>>> Signed-off-by: Aidan Shribman <aidan.shribman@sap.com>
> >>>> Signed-off-by: Orit Wasserman <owasserm@redhat.com>
> >>>> Signed-off-by: Juan Quintela <quintela@redhat.com>
> >>>> ---
> >>>>  arch_init.c      |   28 ++++++++++++++++++++++++++++
> >>>>  hmp.c            |   21 +++++++++++++++++++++
> >>>>  migration.c      |   28 ++++++++++++++++++++++++++++
> >>>>  migration.h      |    4 ++++
> >>>>  qapi-schema.json |   32 +++++++++++++++++++++++++++++++-
> >>>>  qmp-commands.hx  |   35 +++++++++++++++++++++++++++++++++++
> >>>>  6 files changed, 147 insertions(+), 1 deletions(-)
> >>>>
> >>>> diff --git a/arch_init.c b/arch_init.c
> >>>> index 7f12317..9833d54 100644
> >>>> --- a/arch_init.c
> >>>> +++ b/arch_init.c
> >>>> @@ -203,7 +203,11 @@ int64_t xbzrle_cache_resize(int64_t new_size)
> >>>>  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;
> >>>> @@ -233,6 +237,26 @@ 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)
> >>>>  {
> >>>> @@ -257,6 +281,7 @@ 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;
> >>>>      }
> >>>>  
> >>>> @@ -274,6 +299,7 @@ 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;
> >>>> @@ -288,6 +314,8 @@ static int save_xbzrle_page(QEMUFile *f, uint8_t *current_data,
> >>>>      qemu_put_be16(f, encoded_len);
> >>>>      qemu_put_buffer(f, XBZRLE.encoded_buf, encoded_len);
> >>>>      bytes_sent = encoded_len + 1 + 2;
> >>>> +    acct_info.xbzrle_pages++;
> >>>> +    acct_info.xbzrle_bytes += bytes_sent;
> >>>>  
> >>>>      return bytes_sent;
> >>>>  }
> >>>> diff --git a/hmp.c b/hmp.c
> >>>> index 9770d7b..383d5b1 100644
> >>>> --- a/hmp.c
> >>>> +++ b/hmp.c
> >>>> @@ -172,6 +172,27 @@ void hmp_info_migrate(Monitor *mon)
> >>>>                         info->disk->total >> 10);
> >>>>      }
> >>>>  
> >>>> +    if (info->has_xbzrle_cache) {
> >>>> +        monitor_printf(mon, "cache size: %" PRIu64 " bytes\n",
> >>>> +                       info->xbzrle_cache->cache_size);
> >>>> +        if (info->xbzrle_cache->has_xbzrle_bytes) {
> >>>> +            monitor_printf(mon, "xbzrle transferred: %" PRIu64 " kbytes\n",
> >>>> +                           info->xbzrle_cache->xbzrle_bytes >> 10);
> >>>> +        }
> >>>> +        if (info->xbzrle_cache->has_xbzrle_pages) {
> >>>> +            monitor_printf(mon, "xbzrle pages: %" PRIu64 " pages\n",
> >>>> +                           info->xbzrle_cache->xbzrle_pages);
> >>>> +        }
> >>>> +        if (info->xbzrle_cache->has_xbzrle_cache_miss) {
> >>>> +            monitor_printf(mon, "xbzrle cache miss: %" PRIu64 "\n",
> >>>> +                           info->xbzrle_cache->xbzrle_cache_miss);
> >>>> +        }
> >>>> +        if (info->xbzrle_cache->has_xbzrle_overflow) {
> >>>> +            monitor_printf(mon, "xbzrle overflow : %" PRIu64 "\n",
> >>>> +                           info->xbzrle_cache->xbzrle_overflow);
> >>>> +        }
> >>>> +    }
> >>>> +
> >>>>      qapi_free_MigrationInfo(info);
> >>>>      qapi_free_MigrationParameters(params);
> >>>>  }
> >>>> diff --git a/migration.c b/migration.c
> >>>> index 4dc99ba..fb802bc 100644
> >>>> --- a/migration.c
> >>>> +++ b/migration.c
> >>>> @@ -136,6 +136,23 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp)
> >>>>      return params;
> >>>>  }
> >>>>  
> >>>> +static void get_xbzrle_cache_stats(MigrationInfo *info)
> >>>> +{
> >>>> +    if (migrate_use_xbzrle()) {
> >>>> +        info->has_xbzrle_cache = true;
> >>>> +        info->xbzrle_cache = g_malloc0(sizeof(*info->xbzrle_cache));
> >>>> +        info->xbzrle_cache->cache_size = migrate_xbzrle_cache_size();
> >>>> +        info->xbzrle_cache->has_xbzrle_bytes = true;
> >>>> +        info->xbzrle_cache->xbzrle_bytes = xbzrle_mig_bytes_transferred();
> >>>> +        info->xbzrle_cache->has_xbzrle_pages = true;
> >>>> +        info->xbzrle_cache->xbzrle_pages = xbzrle_mig_pages_transferred();
> >>>> +        info->xbzrle_cache->has_xbzrle_cache_miss = true;
> >>>> +        info->xbzrle_cache->xbzrle_cache_miss = xbzrle_mig_pages_cache_miss();
> >>>> +        info->xbzrle_cache->has_xbzrle_overflow = true;
> >>>> +        info->xbzrle_cache->xbzrle_overflow = xbzrle_mig_pages_overflow();
> >>>> +    }
> >>>> +}
> >>>> +
> >>>>  MigrationInfo *qmp_query_migrate(Error **errp)
> >>>>  {
> >>>>      MigrationInfo *info = g_malloc0(sizeof(*info));
> >>>> @@ -144,6 +161,13 @@ MigrationInfo *qmp_query_migrate(Error **errp)
> >>>>      switch (s->state) {
> >>>>      case MIG_STATE_SETUP:
> >>>>          /* no migration has happened ever */
> >>>> +
> >>>> +        /* display xbzrle cache size */
> >>>> +        if (migrate_use_xbzrle()) {
> >>>> +            info->has_xbzrle_cache = true;
> >>>> +            info->xbzrle_cache = g_malloc0(sizeof(*info->xbzrle_cache));
> >>>> +            info->xbzrle_cache->cache_size = migrate_xbzrle_cache_size();
> >>>> +        }
> >>>
> >>> Is it really useful to return this in MIG_SETUP? Can't the cache size
> >>> be queried by some query- command?
> >> I like it this way and it is very simple to use, you need to use query-migrate command if you do migration 
> >> anyway.
> > 
> > But this will only be returned before a migration takes place. Then it will
> > never be returned again. Doesn't seem to be the right place for it.
> It is returned also in MIG_ACTIVE and MIG_COMPLETE (when XBZRLE are active).

That's fine.

> > 
> >> Otherwise we will need to add a query command for each configurable parameters,
> >> so one for speed and another for downtime and probably more in the future.
> > 
> > I don't think this is a problem. We're trying to design QMP commands as we
> > would design a C API, and I'd have different functions to query different things.
> > 
> > Besides, let's not mix what's best to a human user and what's best for a
> > machine protocol. If we add different query commands for different parameters,
> > then it's possible to call them from 'info migrate' if you wish.
> sounds reasonable, I will change it.
> 
> Orit 
> > 
> >> This way we use one command to query the migration setup.
> > 
> > Again, that information would only be returned before a first migration
> > occurs.
> > 
> >>
> >> Orit
> >>>
> >>>>          break;
> >>>>      case MIG_STATE_ACTIVE:
> >>>>          info->has_status = true;
> >>>> @@ -166,8 +190,12 @@ MigrationInfo *qmp_query_migrate(Error **errp)
> >>>>              info->disk->remaining = blk_mig_bytes_remaining();
> >>>>              info->disk->total = blk_mig_bytes_total();
> >>>>          }
> >>>> +
> >>>> +        get_xbzrle_cache_stats(info);
> >>>>          break;
> >>>>      case MIG_STATE_COMPLETED:
> >>>> +        get_xbzrle_cache_stats(info);
> >>>> +
> >>>>          info->has_status = true;
> >>>>          info->status = g_strdup("completed");
> >>>>  
> >>>> diff --git a/migration.h b/migration.h
> >>>> index e4a7cd7..a9852fc 100644
> >>>> --- a/migration.h
> >>>> +++ b/migration.h
> >>>> @@ -91,6 +91,10 @@ 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 a936714..91dee72 100644
> >>>> --- a/qapi-schema.json
> >>>> +++ b/qapi-schema.json
> >>>> @@ -275,6 +275,31 @@
> >>>>             'total_time': 'int', 'duplicate': 'int', 'normal': 'int' } }
> >>>>  
> >>>>  ##
> >>>> +# @XBZRLECacheStats
> >>>> +#
> >>>> +# Detailed XBZRLE migration cache statistics
> >>>> +#
> >>>> +# @cache-size: XBZRLE cache size
> >>>> +#
> >>>> +# @xbzrle-bytes: @optional, amount of bytes already transferred to the target VM
> >>>> +#                only returned when migration is active or completed
> >>>
> >>> s/xbzrle-bytes/transferred-bytes
> >>>
> >>>> +#
> >>>> +# @xbzrle-pages: @optional, amount of pages transferred to the target VM
> >>>> +#                only returned when migration is active or completed
> >>>
> >>> s/xbzrle-pages/transferred-pages
> >>>
> >>>> +#
> >>>> +# @xbzrle-cache-miss: @optional, number of cache miss
> >>>> +#                     only returned when migration is active or completed
> >>>
> >>> s/xbzrle/xbzrle//
> >>>
> >>>> +#
> >>>> +# @xbzrle-overflow: @optional, number of overflows
> >>>> +#                   only returned when migration is active or completed
> >>>
> >>> s/xbzrle///
> >>>
> >>> Besides, all these parameters shouldn't be optional as they are unconditionally
> >>> included (BZRLECacheStats itself is optional as returned by query-migrate).
> >>>
> >>>> +#
> >>>> +# Since: 1.2
> >>>> +##
> >>>> +{ 'type': 'XBZRLECacheStats',
> >>>> +  'data': {'cache-size': 'int', '*xbzrle-bytes': 'int', '*xbzrle-pages': 'int',
> >>>> +           '*xbzrle-cache-miss': 'int', '*xbzrle-overflow': 'int' } }
> >>>> +
> >>>> +##
> >>>>  # @MigrationInfo
> >>>>  #
> >>>>  # Information about current migration process.
> >>>> @@ -292,11 +317,16 @@
> >>>>  #        status, only returned if status is 'active' and it is a block
> >>>>  #        migration
> >>>>  #
> >>>> +# @xbzrle-cache: #optional @XBZRLECacheStats containing detailed XBZRLE
> >>>> +#                migration statistics, only returned if XBZRLE feature is on
> >>>> +#                (since 1.2)
> >>>> +#
> >>>>  # Since: 0.14.0
> >>>>  ##
> >>>>  { 'type': 'MigrationInfo',
> >>>>    'data': {'*status': 'str', '*ram': 'MigrationStats',
> >>>> -           '*disk': 'MigrationStats'} }
> >>>> +           '*disk': 'MigrationStats',
> >>>> +           '*xbzrle-cache': 'XBZRLECacheStats'} }
> >>>>  
> >>>>  ##
> >>>>  # @query-migrate
> >>>> diff --git a/qmp-commands.hx b/qmp-commands.hx
> >>>> index a5a67eb..0546f42 100644
> >>>> --- a/qmp-commands.hx
> >>>> +++ b/qmp-commands.hx
> >>>> @@ -2106,6 +2106,17 @@ The main json-object contains the following:
> >>>>           - "transferred": amount transferred (json-int)
> >>>>           - "remaining": amount remaining (json-int)
> >>>>           - "total": total (json-int)
> >>>> +- "xbzrle-cache": only present if XBZRLE is active.
> >>>> +  It is a json-object with the following XBZRLE information:
> >>>> +         - "cache-size": XBZRLE cache size
> >>>> +         - "xbzrle-bytes": total XBZRLE bytes transferred, only present if
> >>>> +                           status is "active" or "completed"
> >>>> +         - "xbzrle-pages": number of XBZRLE compressed pages, only present if
> >>>> +                           status is "active" or "completed"
> >>>> +         - "cache-miss": number of cache misses, only present if
> >>>> +                           status is "active" or "completed"
> >>>> +         - "overflow": number of XBZRLE overflows, only present if
> >>>> +                           status is "active" or "completed"
> >>>>  Examples:
> >>>>  
> >>>>  1. Before the first migration
> >>>> @@ -2170,6 +2181,30 @@ 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
> >>>>  
> >>>>      {
> >>>
> >>
> > 
>