* Juan Quintela ([email protected]) wrote:
> So we use multifd to transmit zero pages.
>
> Signed-off-by: Juan Quintela <[email protected]>
> ---
> migration/ram.c | 32 +++++++++++++++++++++++++++++++-
> 1 file changed, 31 insertions(+), 1 deletion(-)
>
> diff --git a/migration/ram.c b/migration/ram.c
> index 3536778e19..bdc7cec4cd 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -2168,6 +2168,32 @@ static int ram_save_target_page_legacy(RAMState *rs,
> PageSearchStatus *pss)
> return ram_save_page(rs, pss);
> }
>
> +/**
> + * ram_save_target_page_multifd: save one target page
> + *
> + * Returns the number of pages written
> + *
> + * @rs: current RAM state
> + * @pss: data about the page we want to send
> + */
> +static int ram_save_target_page_multifd(RAMState *rs, PageSearchStatus *pss)
> +{
> + RAMBlock *block = pss->block;
> + ram_addr_t offset = ((ram_addr_t)pss->page) << TARGET_PAGE_BITS;
> + int res;
> +
> + if (!migration_in_postcopy()) {
> + return ram_save_multifd_page(rs, block, offset);
> + }
> +
> + res = save_zero_page(rs, block, offset);
I'm confused; I think I was expecting to see in this patch, the one that
would check the parameter you added and do something different - where
did that go?
Note I think this is quite subtle that the difference here is really
just the ordering rather than adding a zero page test.
Dave
> + if (res > 0) {
> + return res;
> + }
> +
> + return ram_save_page(rs, pss);
> +}
> +
> /**
> * ram_save_host_page: save a whole host page
> *
> @@ -3011,7 +3037,11 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
> ram_control_before_iterate(f, RAM_CONTROL_SETUP);
> ram_control_after_iterate(f, RAM_CONTROL_SETUP);
>
> - (*rsp)->ram_save_target_page = ram_save_target_page_legacy;
> + if (migrate_use_multifd()) {
> + (*rsp)->ram_save_target_page = ram_save_target_page_multifd;
> + } else {
> + (*rsp)->ram_save_target_page = ram_save_target_page_legacy;
> + }
> multifd_send_sync_main(f);
> qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
> qemu_fflush(f);
> --
> 2.34.1
>
--
Dr. David Alan Gilbert / [email protected] / Manchester, UK
