Re: [Qemu-devel] [PATCH v5 11/17] migration: Really use multiple pages at a time

[Peter Xu]

On Mon, Jul 17, 2017 at 03:42:32PM +0200, Juan Quintela wrote:

[...]

>  static int multifd_send_page(uint8_t *address)
>  {
> -    int i;
> +    int i, j;
>      MultiFDSendParams *p = NULL; /* make happy gcc */
> +    static multifd_pages_t pages;
> +    static bool once;
> +
> +    if (!once) {
> +        multifd_init_group(&pages);
> +        once = true;

Would it be good to put the "pages" into multifd_send_state? One is to
stick globals together; another benefit is that we can remove the
"once" here: we can then init the "pages" when init multifd_send_state
struct (but maybe with a better name?...).

(there are similar static variables in multifd_recv_page() as well, if
 this one applies, then we can possibly use multifd_recv_state for
 that one)

> +    }
> +
> +    pages.iov[pages.num].iov_base = address;
> +    pages.iov[pages.num].iov_len = TARGET_PAGE_SIZE;
> +    pages.num++;
> +
> +    if (pages.num < (pages.size - 1)) {
> +        return UINT16_MAX;

Nit: shall we define something for readability?  Like:

#define  MULTIFD_FD_INVALID  UINT16_MAX

> +    }
>  
>      qemu_sem_wait(&multifd_send_state->sem);
>      qemu_mutex_lock(&multifd_send_state->mutex);
> @@ -530,7 +559,12 @@ static int multifd_send_page(uint8_t *address)
>      }
>      qemu_mutex_unlock(&multifd_send_state->mutex);
>      qemu_mutex_lock(&p->mutex);
> -    p->address = address;
> +    p->pages.num = pages.num;
> +    for (j = 0; j < pages.size; j++) {
> +        p->pages.iov[j].iov_base = pages.iov[j].iov_base;
> +        p->pages.iov[j].iov_len = pages.iov[j].iov_len;
> +    }
> +    pages.num = 0;
>      qemu_mutex_unlock(&p->mutex);
>      qemu_sem_post(&p->sem);
>  
> -- 
> 2.9.4
> 

-- 
Peter Xu