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

[Juan Quintela]

Peter Xu <address@hidden> 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?...).

I did to be able to free it.

> (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)

Also there.

>> +    }
>> +
>> +    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

Also done.

MULTIFD_CONTINUE

But I am open to changes.


>> +    }
>>  
>>      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
>>