Peter Xu <pet...@redhat.com> wrote:
> This patch simplifies unqueue_page() on both sides of it (itself, and caller).
>
> Firstly, due to the fact that right after unqueue_page() returned true, we'll
> definitely send a huge page (see ram_save_huge_page() call - it will _never_
> exit before finish sending that huge page), so unqueue_page() does not need to
> jump in small page size if huge page is enabled on the ramblock. IOW, it's
> destined that only the 1st 4K page will be valid, when unqueue the 2nd+ time
> we'll notice the whole huge page has already been sent anyway. Switching to
> operating on huge page reduces a lot of the loops of redundant unqueue_page().
>
> Meanwhile, drop the dirty check. It's not helpful to call test_bit() every
> time to jump over clean pages, as ram_save_host_page() has already done so,
> while in a faster way (see commit ba1b7c812c ("migration/ram: Optimize
> ram_save_host_page()", 2021-05-13)). So that's not necessary too.
>
> Drop the two tracepoints along the way - based on above analysis it's very
> possible that no one is really using it..
>
> Signed-off-by: Peter Xu <pet...@redhat.com>
Reviewed-by: Juan Quintela <quint...@redhat.com>
queued.
I added the extra tracepoint that you added later.
