* Wei Yang (richardw.y...@linux.intel.com) wrote:
> During migration, we would sync bitmap from ram_list.dirty_memory to
> RAMBlock.bmap in cpu_physical_memory_sync_dirty_bitmap().
>
> Since we set RAMBlock.bmap and ram_list.dirty_memory both to all 1, this
> means at the first round this sync is meaningless and is a duplicated
> work.
>
> Leaving RAMBlock->bmap blank on allocating would have a side effect on
> migration_dirty_pages, since it is calculated from the result of
> cpu_physical_memory_sync_dirty_bitmap(). To keep it right, we need to
> set migration_dirty_pages to 0 in ram_state_init().
>
> Signed-off-by: Wei Yang <richardw.y...@linux.intel.com>
I've looked at this for a while, and I think it's OK, so
Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
Peter, Juan: Can you just see if there's arny reason this would be bad,
but I think it's actually more sensible than what we have.
Dave
> ---
> migration/ram.c | 8 +-------
> 1 file changed, 1 insertion(+), 7 deletions(-)
>
> diff --git a/migration/ram.c b/migration/ram.c
> index 95c51109d2..417874707d 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -3151,12 +3151,7 @@ static int ram_state_init(RAMState **rsp)
> qemu_mutex_init(&(*rsp)->src_page_req_mutex);
> QSIMPLEQ_INIT(&(*rsp)->src_page_requests);
>
> - /*
> - * Count the total number of pages used by ram blocks not including any
> - * gaps due to alignment or unplugs.
> - */
> - (*rsp)->migration_dirty_pages = ram_bytes_total() >> TARGET_PAGE_BITS;
> -
> + (*rsp)->migration_dirty_pages = 0;
> ram_state_reset(*rsp);
>
> return 0;
> @@ -3172,7 +3167,6 @@ static void ram_list_init_bitmaps(void)
> RAMBLOCK_FOREACH_NOT_IGNORED(block) {
> pages = block->max_length >> TARGET_PAGE_BITS;
> block->bmap = bitmap_new(pages);
> - bitmap_set(block->bmap, 0, pages);
> if (migrate_postcopy_ram()) {
> block->unsentmap = bitmap_new(pages);
> bitmap_set(block->unsentmap, 0, pages);
> --
> 2.19.1
>
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
