RE: [PATCH 2/3] Reduce the time of checkpoint for COLO

[Rao, Lei]

Got it.
It looks more reasonable. Will be changed in V2.

Thanks,
Lei.

-----Original Message-----
From: Li Zhijian <lizhijian@cn.fujitsu.com> 
Sent: Tuesday, September 22, 2020 2:58 PM
To: Rao, Lei <lei.rao@intel.com>; Zhang, Chen <chen.zhang@intel.com>; 
jasowang@redhat.com; quintela@redhat.com; dgilbert@redhat.com; 
pbonzini@redhat.com
Cc: qemu-devel@nongnu.org
Subject: Re: [PATCH 2/3] Reduce the time of checkpoint for COLO



On 9/19/20 11:10 AM, leirao wrote:
> we should set ram_bulk_stage to false after ram_state_init, otherwise 
> the bitmap will be unused in migration_bitmap_find_dirty.
> all pages in ram cache will be flushed to the ram of secondary guest 
> for each checkpoint.
>
> Signed-off-by: leirao <lei.rao@intel.com>
> ---
>   migration/ram.c | 12 ++++++++++++
>   1 file changed, 12 insertions(+)
>
> diff --git a/migration/ram.c b/migration/ram.c index 76d4fee..6a2b6c1 
> 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -3019,6 +3019,17 @@ static void 
> decompress_data_with_multi_threads(QEMUFile *f,
>   }
>   
>   /*
> + * we must set ram_bulk_stage to fasle, otherwise in
> + * migation_bitmap_find_dirty the bitmap will be unused and
> + * all the pages in ram cache wil be flushed to the ram of
> + * secondary VM.
> + */
> +static void colo_set_ram_state(RAMState *rsp)
this function name is too general, how about

colo_init_ram_state(ram_state)
{
     ram_state_init(&ram_state);
     ram_state->ram_bulk_stage = false;
}

Thanks
Zhijian

> +{
> +    rsp->ram_bulk_stage = false;
> +}
> +
> +/*
>    * colo cache: this is for secondary VM, we cache the whole
>    * memory of the secondary VM, it is need to hold the global lock
>    * to call this helper.
> @@ -3062,6 +3073,7 @@ int colo_init_ram_cache(void)
>       }
>   
>       ram_state_init(&ram_state);
> +    colo_set_ram_state(ram_state);
>       return 0;
>   }
>