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

[Peter Xu <peterx@redhat.com>]

On Thu, Jul 20, 2017 at 05:49:47PM +0800, Peter Xu wrote:
> 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

Sorry I misunderstood. INVALID may not suite here. Maybe
MULTIFD_FD_CONTINUE?

(afaiu we send this before we send the real fd_num for the chunk)

-- 
Peter Xu