Re: [Qemu-devel] [PATCH 13/18] arch_init: adjust ram_save_setup() for migrate_is_localhost

[Paolo Bonzini <pbonzini@redhat.com>]

Il 21/08/2013 09:18, Lei Li ha scritto:
> Send all the ram blocks hooked by save_page, which will copy
> ram page and MADV_DONTNEED the page just copied.

You should implement this entirely in the hook.

It will be a little less efficient because of the dirty bitmap overhead,
but you should aim at having *zero* changes in arch_init.c and migration.c.

Paolo

> 
> Signed-off-by: Lei Li <lilei@linux.vnet.ibm.com>
> ---
>  arch_init.c |   19 +++++++++++++------
>  1 files changed, 13 insertions(+), 6 deletions(-)
> 
> diff --git a/arch_init.c b/arch_init.c
> index 434a4ca..cbbb4db 100644
> --- a/arch_init.c
> +++ b/arch_init.c
> @@ -474,7 +474,7 @@ static int ram_save_block(QEMUFile *f, bool last_stage)
>              /* In doubt sent page as normal */
>              bytes_sent = -1;
>              ret = ram_control_save_page(f, block->offset,
> -                               offset, TARGET_PAGE_SIZE, &bytes_sent);
> +                                        offset, TARGET_PAGE_SIZE, &bytes_sent);
>  
>              if (ret != RAM_SAVE_CONTROL_NOT_SUPP) {
>                  if (ret != RAM_SAVE_CONTROL_DELAYED) {
> @@ -613,11 +613,13 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
>      RAMBlock *block;
>      int64_t ram_pages = last_ram_offset() >> TARGET_PAGE_BITS;
>  
> -    migration_bitmap = bitmap_new(ram_pages);
> -    bitmap_set(migration_bitmap, 0, ram_pages);
> -    migration_dirty_pages = ram_pages;
> -    mig_throttle_on = false;
> -    dirty_rate_high_cnt = 0;
> +    if (!migrate_is_localhost()) {
> +        migration_bitmap = bitmap_new(ram_pages);
> +        bitmap_set(migration_bitmap, 0, ram_pages);
> +        migration_dirty_pages = ram_pages;
> +        mig_throttle_on = false;
> +        dirty_rate_high_cnt = 0;
> +    }
>  
>      if (migrate_use_xbzrle()) {
>          XBZRLE.cache = cache_init(migrate_xbzrle_cache_size() /
> @@ -641,6 +643,11 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
>      migration_bitmap_sync();
>      qemu_mutex_unlock_iothread();
>  
> +    if (migrate_is_localhost()) {
> +        ram_save_blocks(f);
> +        return 0;
> +    }
> +
>      qemu_put_be64(f, ram_bytes_total() | RAM_SAVE_FLAG_MEM_SIZE);
>  
>      QTAILQ_FOREACH(block, &ram_list.blocks, next) {
>