Re: [Qemu-devel] [PATCH 30/51] ram: Move src_page_req* to RAMState

[Peter Xu]

On Thu, Mar 23, 2017 at 09:45:23PM +0100, Juan Quintela wrote:
> This are the last postcopy fields still at MigrationState.  Once there

s/This/These/

> Move MigrationSrcPageRequest to ram.c and remove MigrationState
> parameters where appropiate.
> 
> Signed-off-by: Juan Quintela <address@hidden>

Reviewed-by: Peter Xu <address@hidden>

One question below though...

[...]

> @@ -1191,19 +1204,18 @@ static bool get_queued_page(RAMState *rs, 
> MigrationState *ms,
>   *
>   * It should be empty at the end anyway, but in error cases there may
>   * xbe some left.
> - *
> - * @ms: current migration state
>   */
> -void flush_page_queue(MigrationState *ms)
> +void flush_page_queue(void)
>  {
> -    struct MigrationSrcPageRequest *mspr, *next_mspr;
> +    struct RAMSrcPageRequest *mspr, *next_mspr;
> +    RAMState *rs = &ram_state;
>      /* This queue generally should be empty - but in the case of a failed
>       * migration might have some droppings in.
>       */
>      rcu_read_lock();

Could I ask why we are taking the RCU read lock rather than the mutex
here?

> -    QSIMPLEQ_FOREACH_SAFE(mspr, &ms->src_page_requests, next_req, next_mspr) 
> {
> +    QSIMPLEQ_FOREACH_SAFE(mspr, &rs->src_page_requests, next_req, next_mspr) 
> {
>          memory_region_unref(mspr->rb->mr);
> -        QSIMPLEQ_REMOVE_HEAD(&ms->src_page_requests, next_req);
> +        QSIMPLEQ_REMOVE_HEAD(&rs->src_page_requests, next_req);
>          g_free(mspr);
>      }
>      rcu_read_unlock();

Thanks,

-- peterx