Re: [Qemu-devel] [PATCH v4 37/47] Page request: Consume pages off the post-copy queue

[Paolo Bonzini]

Il 03/10/2014 19:47, Dr. David Alan Gilbert (git) ha scritto:
> +        /*
> +         * Don't break host-page chunks up with queue items
> +         * so only unqueue if,
> +         *   a) The last item came from the queue anyway
> +         *   b) The last sent item was the last target-page in a host page
> +         */
> +        if (last_was_from_queue || (!last_sent_block) ||

Extra parentheses.  Is the last_was_from_queue check necessary?  Or
would one of the other checks be true anyway if last_was_from_queue is true?

> +            /* We're sending this page, and since it's postcopy nothing else
> +             * will dirty it, and we must make sure it doesn't get sent 
> again.
> +             */
> +            if (!migration_bitmap_clear_dirty(bitoffset << 
> TARGET_PAGE_BITS)) {
> +                DPRINTF("%s: Not dirty for postcopy %s/%zx bito=%zx 
> (sent=%d)",
> +                        __func__, tmpblock->idstr, tmpoffset, bitoffset,
> +                        test_bit(bitoffset, ms->sentmap));

If a DPRINTF occurs in a loop, please change it to a tracepoint.

This function looks like a candidate for cleaning its logic up and/or
splitting it.  But it can be done later by the poor soul who will touch
it next. :)

Paolo