Re: [PATCH v6 3/3] migration: Make dirty_bytes_last_sync atomic

[Richard Henderson <richard.henderson@linaro.org>]

On 4/27/23 10:52, Juan Quintela wrote:
> As we set its value, it needs to be operated with atomics.
> We rename it from remaining to better reflect its meaning.
> 
> Statistics always return the real reamaining bytes.  This was used to
> store how much pages where dirty on the previous generation, so we can
> calculate the expected downtime as: dirty_bytes_last_sync /
> current_bandwith.
> 
> If we use the actual remaining bytes, we would see a very small value
> at the end of the iteration.
> 
> Signed-off-by: Juan Quintela<quintela@redhat.com>
> Reviewed-by: Peter Xu<peterx@redhat.com>
> 
> ---
> 
> I am open to use ram_bytes_remaining() in its only use and be more
> "optimistic" about the downtime.
> 
> Don't use __nocheck() functions.
> Use stat64_get() now that it exists.
> ---
>   migration/migration.c | 3 ++-
>   migration/ram.c       | 2 +-
>   migration/ram.h       | 2 +-
>   3 files changed, 4 insertions(+), 3 deletions(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~