On Tue, Oct 29, 2024 at 08:39:07PM +0530, Prasad Pandit wrote:
> From: Prasad Pandit <p...@fedoraproject.org>
>
> Refactor ram_save_target_page legacy and multifd
> functions into one. Other than simplifying it,
> it avoids reinitialization of the 'migration_ops'
> object, when migration moves from multifd to postcopy
> phase.
>
> Signed-off-by: Prasad Pandit <p...@fedoraproject.org>
> ---
> migration/ram.c | 54 ++++++++++++++++++++-----------------------------
> 1 file changed, 22 insertions(+), 32 deletions(-)
>
> diff --git a/migration/ram.c b/migration/ram.c
> index 326ce7eb79..f9a6395d00 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -1985,18 +1985,36 @@ int ram_save_queue_pages(const char *rbname,
> ram_addr_t start, ram_addr_t len,
> }
>
> /**
> - * ram_save_target_page_legacy: save one target page
> + * ram_save_target_page_common:
> + * send one target page to multifd workers OR save one target page.
> *
> - * Returns the number of pages written
> + * Multifd mode: returns 1 if the page was queued, -1 otherwise.
> + *
> + * Non-multifd mode: 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_legacy(RAMState *rs, PageSearchStatus *pss)
> +static int ram_save_target_page_common(RAMState *rs, PageSearchStatus *pss)
> {
> ram_addr_t offset = ((ram_addr_t)pss->page) << TARGET_PAGE_BITS;
> int res;
>
> + if (migrate_multifd()) {
> + RAMBlock *block = pss->block;
> + /*
> + * While using multifd live migration, we still need to handle zero
> + * page checking on the migration main thread.
> + */
> + if (migrate_zero_page_detection() == ZERO_PAGE_DETECTION_LEGACY) {
> + if (save_zero_page(rs, pss, offset)) {
There's one more save_zero_page() below. Please consider properly merging
them.
> + return 1;
> + }
> + }
> +
> + return ram_save_multifd_page(block, offset);
> + }
> +
> if (control_save_page(pss, offset, &res)) {
> return res;
> }
> @@ -2008,32 +2026,6 @@ static int ram_save_target_page_legacy(RAMState *rs,
> PageSearchStatus *pss)
> return ram_save_page(rs, pss);
> }
>
> -/**
> - * ram_save_target_page_multifd: send one target page to multifd workers
> - *
> - * Returns 1 if the page was queued, -1 otherwise.
> - *
> - * @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;
> -
> - /*
> - * While using multifd live migration, we still need to handle zero
> - * page checking on the migration main thread.
> - */
> - if (migrate_zero_page_detection() == ZERO_PAGE_DETECTION_LEGACY) {
> - if (save_zero_page(rs, pss, offset)) {
> - return 1;
> - }
> - }
> -
> - return ram_save_multifd_page(block, offset);
> -}
> -
> /* Should be called before sending a host page */
> static void pss_host_page_prepare(PageSearchStatus *pss)
> {
> @@ -3055,12 +3047,10 @@ static int ram_save_setup(QEMUFile *f, void *opaque,
> Error **errp)
> }
>
> migration_ops = g_malloc0(sizeof(MigrationOps));
> + migration_ops->ram_save_target_page = ram_save_target_page_common;
If we want to merge the hooks, we should drop the hook in one shot, then
call the new function directly.
>
> if (migrate_multifd()) {
> multifd_ram_save_setup();
> - migration_ops->ram_save_target_page = ram_save_target_page_multifd;
> - } else {
> - migration_ops->ram_save_target_page = ram_save_target_page_legacy;
> }
>
> bql_unlock();
> --
> 2.47.0
>
--
Peter Xu
