Re: [Qemu-devel] [PATCH 2/5] ram: Move ZERO_TARGET_PAGE inside XBZRLE

[Dr. David Alan Gilbert]

* Juan Quintela (address@hidden) wrote:
> It was only used by XBZRLE anyways.
> 
> Signed-off-by: Juan Quintela <address@hidden>

Reviewed-by: Dr. David Alan Gilbert <address@hidden>

> ---
>  migration/ram.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/migration/ram.c b/migration/ram.c
> index e503277..04b55a7 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -66,8 +66,6 @@
>  /* 0x80 is reserved in migration.h start with 0x100 next */
>  #define RAM_SAVE_FLAG_COMPRESS_PAGE    0x100
>  
> -static uint8_t *ZERO_TARGET_PAGE;
> -
>  static inline bool is_zero_range(uint8_t *p, uint64_t size)
>  {
>      return buffer_is_zero(p, size);
> @@ -83,6 +81,8 @@ static struct {
>      /* Cache for XBZRLE, Protected by lock. */
>      PageCache *cache;
>      QemuMutex lock;
> +    /* it will store a page full of zeros */
> +    uint8_t *zero_target_page;
>  } XBZRLE;
>  
>  /* buffer used for XBZRLE decoding */
> @@ -509,7 +509,7 @@ 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,
> +    cache_insert(XBZRLE.cache, current_addr, XBZRLE.zero_target_page,
>                   rs->bitmap_sync_count);
>  }
>  
> @@ -1453,10 +1453,11 @@ static void ram_migration_cleanup(void *opaque)
>          cache_fini(XBZRLE.cache);
>          g_free(XBZRLE.encoded_buf);
>          g_free(XBZRLE.current_buf);
> -        g_free(ZERO_TARGET_PAGE);
> +        g_free(XBZRLE.zero_target_page);
>          XBZRLE.cache = NULL;
>          XBZRLE.encoded_buf = NULL;
>          XBZRLE.current_buf = NULL;
> +        XBZRLE.zero_target_page = NULL;
>      }
>      XBZRLE_cache_unlock();
>      migration_page_queue_free(rs);
> @@ -1877,7 +1878,7 @@ static int ram_state_init(RAMState *rs)
>  
>      if (migrate_use_xbzrle()) {
>          XBZRLE_cache_lock();
> -        ZERO_TARGET_PAGE = g_malloc0(TARGET_PAGE_SIZE);
> +        XBZRLE.zero_target_page = g_malloc0(TARGET_PAGE_SIZE);
>          XBZRLE.cache = cache_init(migrate_xbzrle_cache_size() /
>                                    TARGET_PAGE_SIZE,
>                                    TARGET_PAGE_SIZE);
> -- 
> 2.9.4
> 
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK