Re: [Qemu-devel] [PATCH 09/11] Add migration accounting for normal and duplicate pages

[Luiz Capitulino <lcapitulino@redhat.com>]

On Tue, 31 Jul 2012 11:36:03 +0300
Orit Wasserman <owasserm@redhat.com> wrote:

> On 07/30/2012 10:30 PM, Luiz Capitulino wrote:
> > On Sun, 29 Jul 2012 12:43:01 +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      |   38 ++++++++++++++++++++++++++++++++++++++
> >>  migration.c      |    4 ++++
> >>  migration.h      |    5 +++++
> >>  qapi-schema.json |    8 ++++++--
> >>  qmp-commands.hx  |   14 +++++++++++---
> >>  5 files changed, 64 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/arch_init.c b/arch_init.c
> >> index d709ccb..7f12317 100644
> >> --- a/arch_init.c
> >> +++ b/arch_init.c
> >> @@ -199,6 +199,40 @@ 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 iterations;
> >> +} 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;
> >> +}
> >> +
> >>  static void save_block_hdr(QEMUFile *f, RAMBlock *block, ram_addr_t offset,
> >>          int cont, int flag)
> >>  {
> >> @@ -293,6 +327,7 @@ 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;
> >> @@ -308,6 +343,7 @@ 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 */
> >> @@ -429,6 +465,7 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
> >>          }
> >>          XBZRLE.encoded_buf = g_malloc0(TARGET_PAGE_SIZE);
> >>          XBZRLE.current_buf = g_malloc(TARGET_PAGE_SIZE);
> >> +        acct_clear();
> >>      }
> >>  
> >>      /* Make sure all dirty bits are set */
> >> @@ -477,6 +514,7 @@ 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/migration.c b/migration.c
> >> index bc2231d..4dc99ba 100644
> >> --- a/migration.c
> >> +++ b/migration.c
> >> @@ -156,6 +156,8 @@ 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();
> >>  
> >>          if (blk_mig_active()) {
> >>              info->has_disk = true;
> >> @@ -175,6 +177,8 @@ MigrationInfo *qmp_query_migrate(Error **errp)
> >>          info->ram->remaining = 0;
> >>          info->ram->total = ram_bytes_total();
> >>          info->ram->total_time = s->total_time;
> >> +        info->ram->duplicate = dup_mig_pages_transferred();
> >> +        info->ram->normal = norm_mig_pages_transferred();
> >>          break;
> >>      case MIG_STATE_ERROR:
> >>          info->has_status = true;
> >> diff --git a/migration.h b/migration.h
> >> index 337e225..e4a7cd7 100644
> >> --- a/migration.h
> >> +++ b/migration.h
> >> @@ -87,6 +87,11 @@ 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);
> >> +
> >>  /**
> >>   * @migrate_add_blocker - prevent migration from proceeding
> >>   *
> >> diff --git a/qapi-schema.json b/qapi-schema.json
> >> index 04adcee..a936714 100644
> >> --- a/qapi-schema.json
> >> +++ b/qapi-schema.json
> >> @@ -264,11 +264,15 @@
> >>  #        migration has ended, it returns the total migration
> >>  #        time. (since 1.2)
> >>  #
> >> -# Since: 0.14.0.
> >> +# @duplicate: number of duplicate pages (since 1.2)
> >> +#
> >> +# @normal : number of normal pages (since 1.2)
> > 
> > Is the number of pages actually useful? I think this should be in bytes,
> > just like the other stats.
> > 
> Why? the pages are always the same size (4k), and what is interesting here is the number of the normal
> pages compared to the duplicate pages not the total bytes.
> In XBZRLE there is meaning both for the bytes and the number of pages because the page size is not fixed.

Can we have both them?

> 
> Orit
> >> +#
> >> +# Since: 0.14.0
> >>  ##
> >>  { 'type': 'MigrationStats',
> >>    'data': {'transferred': 'int', 'remaining': 'int', 'total': 'int' ,
> >> -           'total_time': 'int' } }
> >> +           'total_time': 'int', 'duplicate': 'int', 'normal': 'int' } }
> >>  
> >>  ##
> >>  # @MigrationInfo
> >> diff --git a/qmp-commands.hx b/qmp-commands.hx
> >> index cfc950e..a5a67eb 100644
> >> --- a/qmp-commands.hx
> >> +++ b/qmp-commands.hx
> >> @@ -2099,6 +2099,8 @@ 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)
> >> @@ -2119,7 +2121,9 @@ Examples:
> >>          "ram":{
> >>            "transferred":123,
> >>            "remaining":123,
> >> -          "total":246
> >> +          "total":246,
> >> +          "duplicate":123,
> >> +          "normal":123
> >>          }
> >>       }
> >>     }
> >> @@ -2138,7 +2142,9 @@ Examples:
> >>           "ram":{
> >>              "transferred":123,
> >>              "remaining":123,
> >> -            "total":246
> >> +            "total":246,
> >> +            "duplicate":123,
> >> +            "normal":123
> >>           }
> >>        }
> >>     }
> >> @@ -2152,7 +2158,9 @@ Examples:
> >>           "ram":{
> >>              "total":1057024,
> >>              "remaining":1053304,
> >> -            "transferred":3720
> >> +            "transferred":3720,
> >> +            "duplicate":123,
> >> +            "normal":123
> >>           },
> >>           "disk":{
> >>              "total":20971520,
> > 
>