Re: [Qemu-devel] [PATCH] migration: static variables will not be reset at second migration

[Juan Quintela <quintela@redhat.com>]

<arei.gonglei@huawei.com> wrote:
> From: ChenLiang <chenliang88@huawei.com>
>
> The static variables in migration_bitmap_sync will not be reset in
> the case of a second attempted migration.
>
> Signed-off-by: ChenLiang <chenliang88@huawei.com>
> Signed-off-by: Gonglei <arei.gonglei@huawei.com>

Good catch.  Applied..

> ---
>  arch_init.c | 15 ++++++++++++---
>  1 file changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/arch_init.c b/arch_init.c
> index 60c975d..10516cb 100644
> --- a/arch_init.c
> +++ b/arch_init.c
> @@ -468,15 +468,23 @@ static void migration_bitmap_sync_range(ram_addr_t start, ram_addr_t length)
>  
>  
>  /* Needs iothread lock! */
> +/* Fix me: there are too many global variables used in migration process. */
> +static int64_t start_time;
> +static int64_t bytes_xfer_prev;
> +static int64_t num_dirty_pages_period;
> +
> +static void migration_bitmap_sync_init(void)
> +{
> +    start_time = 0;
> +    bytes_xfer_prev = 0;
> +    num_dirty_pages_period = 0;
> +}
>  
>  static void migration_bitmap_sync(void)
>  {
>      RAMBlock *block;
>      uint64_t num_dirty_pages_init = migration_dirty_pages;
>      MigrationState *s = migrate_get_current();
> -    static int64_t start_time;
> -    static int64_t bytes_xfer_prev;
> -    static int64_t num_dirty_pages_period;
>      int64_t end_time;
>      int64_t bytes_xfer_now;
>  
> @@ -733,6 +741,7 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
>      migration_dirty_pages = ram_pages;
>      mig_throttle_on = false;
>      dirty_rate_high_cnt = 0;
> +    migration_bitmap_sync_init();
>  
>      if (migrate_use_xbzrle()) {
>          qemu_mutex_lock_iothread();