Re: [Qemu-devel] [PATCH 05/51] ram: Move bitmap_sync_count into RAMState

[Peter Xu]

On Thu, Mar 23, 2017 at 09:44:58PM +0100, Juan Quintela wrote:
> Signed-off-by: Juan Quintela <address@hidden>
> Reviewed-by: Dr. David Alan Gilbert <address@hidden>

Reviewed-by: Peter Xu <address@hidden>

(I see that we have MigrationStats.dirty_pages_rate which looks
 similar to this one. Maybe one day we can merge these two?)

> ---
>  migration/ram.c | 23 ++++++++++++-----------
>  1 file changed, 12 insertions(+), 11 deletions(-)
> 
> diff --git a/migration/ram.c b/migration/ram.c
> index 1d5bf22..f811e81 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -45,8 +45,6 @@
>  #include "qemu/rcu_queue.h"
>  #include "migration/colo.h"
>  
> -static uint64_t bitmap_sync_count;
> -
>  /***********************************************************/
>  /* ram save/restore */
>  
> @@ -154,6 +152,8 @@ struct RAMState {
>      bool ram_bulk_stage;
>      /* How many times we have dirty too many pages */
>      int dirty_rate_high_cnt;
> +    /* How many times we have synchronized the bitmap */
> +    uint64_t bitmap_sync_count;
>  };
>  typedef struct RAMState RAMState;
>  
> @@ -471,7 +471,7 @@ static void xbzrle_cache_zero_page(RAMState *rs, 
> ram_addr_t current_addr)
>      /* We don't care if this fails to allocate a new cache page
>       * as long as it updated an old one */
>      cache_insert(XBZRLE.cache, current_addr, ZERO_TARGET_PAGE,
> -                 bitmap_sync_count);
> +                 rs->bitmap_sync_count);
>  }
>  
>  #define ENCODING_FLAG_XBZRLE 0x1
> @@ -483,6 +483,7 @@ static void xbzrle_cache_zero_page(RAMState *rs, 
> ram_addr_t current_addr)
>   *          0 means that page is identical to the one already sent
>   *          -1 means that xbzrle would be longer than normal
>   *
> + * @rs: current RAM state
>   * @f: QEMUFile where to send the data
>   * @current_data: contents of the page
>   * @current_addr: addr of the page
> @@ -491,7 +492,7 @@ static void xbzrle_cache_zero_page(RAMState *rs, 
> ram_addr_t current_addr)
>   * @last_stage: if we are at the completion stage
>   * @bytes_transferred: increase it with the number of transferred bytes
>   */
> -static int save_xbzrle_page(QEMUFile *f, uint8_t **current_data,
> +static int save_xbzrle_page(RAMState *rs, QEMUFile *f, uint8_t 
> **current_data,
>                              ram_addr_t current_addr, RAMBlock *block,
>                              ram_addr_t offset, bool last_stage,
>                              uint64_t *bytes_transferred)
> @@ -499,11 +500,11 @@ static int save_xbzrle_page(QEMUFile *f, uint8_t 
> **current_data,
>      int encoded_len = 0, bytes_xbzrle;
>      uint8_t *prev_cached_page;
>  
> -    if (!cache_is_cached(XBZRLE.cache, current_addr, bitmap_sync_count)) {
> +    if (!cache_is_cached(XBZRLE.cache, current_addr, rs->bitmap_sync_count)) 
> {
>          acct_info.xbzrle_cache_miss++;
>          if (!last_stage) {
>              if (cache_insert(XBZRLE.cache, current_addr, *current_data,
> -                             bitmap_sync_count) == -1) {
> +                             rs->bitmap_sync_count) == -1) {
>                  return -1;
>              } else {
>                  /* update *current_data when the page has been
> @@ -658,7 +659,7 @@ static void migration_bitmap_sync(RAMState *rs)
>      int64_t end_time;
>      int64_t bytes_xfer_now;
>  
> -    bitmap_sync_count++;
> +    rs->bitmap_sync_count++;
>  
>      if (!bytes_xfer_prev) {
>          bytes_xfer_prev = ram_bytes_transferred();
> @@ -720,9 +721,9 @@ static void migration_bitmap_sync(RAMState *rs)
>          start_time = end_time;
>          num_dirty_pages_period = 0;
>      }
> -    s->dirty_sync_count = bitmap_sync_count;
> +    s->dirty_sync_count = rs->bitmap_sync_count;
>      if (migrate_use_events()) {
> -        qapi_event_send_migration_pass(bitmap_sync_count, NULL);
> +        qapi_event_send_migration_pass(rs->bitmap_sync_count, NULL);
>      }
>  }
>  
> @@ -829,7 +830,7 @@ static int ram_save_page(RAMState *rs, MigrationState 
> *ms, QEMUFile *f,
>              ram_release_pages(ms, block->idstr, pss->offset, pages);
>          } else if (!rs->ram_bulk_stage &&
>                     !migration_in_postcopy(ms) && migrate_use_xbzrle()) {
> -            pages = save_xbzrle_page(f, &p, current_addr, block,
> +            pages = save_xbzrle_page(rs, f, &p, current_addr, block,
>                                       offset, last_stage, bytes_transferred);
>              if (!last_stage) {
>                  /* Can't send this cached data async, since the cache page
> @@ -1998,7 +1999,7 @@ static int ram_save_init_globals(RAMState *rs)
>      int64_t ram_bitmap_pages; /* Size of bitmap in pages, including gaps */
>  
>      rs->dirty_rate_high_cnt = 0;
> -    bitmap_sync_count = 0;
> +    rs->bitmap_sync_count = 0;
>      migration_bitmap_sync_init();
>      qemu_mutex_init(&migration_bitmap_mutex);
>  
> -- 
> 2.9.3
> 
> 

-- peterx