Prasad Pandit <[email protected]> writes: > From: Prasad Pandit <[email protected]> > > Refactor ram_save_target_page legacy and multifd > functions into one. Other than simplifying it, > it frees 'migration_ops' object from usage, so it > is expunged. > > When both Multifd and Postcopy modes are enabled, > to avoid errors, the Multifd threads are active until > migration reaches the Postcopy mode. This is done by > checking the state returned by migration_in_postcopy().
This patch should be just the actual refactoring on top of master, with no mention to postcopy at all. > > Signed-off-by: Prasad Pandit <[email protected]> > --- > migration/multifd-nocomp.c | 3 +- > migration/ram.c | 74 ++++++++++++-------------------------- > 2 files changed, 24 insertions(+), 53 deletions(-) > > v1: Further refactor ram_save_target_page() function to conflate > save_zero_page() calls. > > Add migration_in_postcopy() call to check migration state > instead of combining it with migrate_multifd(). > > v0: > https://lore.kernel.org/qemu-devel/[email protected]/T/#u > > diff --git a/migration/multifd-nocomp.c b/migration/multifd-nocomp.c > index 55191152f9..e92821e8f6 100644 > --- a/migration/multifd-nocomp.c > +++ b/migration/multifd-nocomp.c > @@ -14,6 +14,7 @@ > #include "exec/ramblock.h" > #include "exec/target_page.h" > #include "file.h" > +#include "migration.h" > #include "multifd.h" > #include "options.h" > #include "qapi/error.h" > @@ -345,7 +346,7 @@ retry: > > int multifd_ram_flush_and_sync(void) > { > - if (!migrate_multifd()) { > + if (!migrate_multifd() || migration_in_postcopy()) { > return 0; > } > > diff --git a/migration/ram.c b/migration/ram.c > index 05ff9eb328..9d1ec6209c 100644 > --- a/migration/ram.c > +++ b/migration/ram.c > @@ -467,13 +467,6 @@ void ram_transferred_add(uint64_t bytes) > } > } > > -struct MigrationOps { > - int (*ram_save_target_page)(RAMState *rs, PageSearchStatus *pss); > -}; > -typedef struct MigrationOps MigrationOps; > - > -MigrationOps *migration_ops; > - > static int ram_save_host_page_urgent(PageSearchStatus *pss); > > /* NOTE: page is the PFN not real ram_addr_t. */ > @@ -1323,9 +1316,9 @@ static int find_dirty_block(RAMState *rs, > PageSearchStatus *pss) > pss->page = 0; > pss->block = QLIST_NEXT_RCU(pss->block, next); > if (!pss->block) { > - if (migrate_multifd() && > - (!migrate_multifd_flush_after_each_section() || > - migrate_mapped_ram())) { > + if (migrate_multifd() && !migration_in_postcopy() > + && (!migrate_multifd_flush_after_each_section() > + || migrate_mapped_ram())) { This is getting out of hand. We can't keep growing this condition every time something new comes up. Any ideas? > QEMUFile *f = rs->pss[RAM_CHANNEL_PRECOPY].pss_channel; > int ret = multifd_ram_flush_and_sync(); > if (ret < 0) { > @@ -1986,55 +1979,39 @@ 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: save one target page to the precopy thread > + * OR to multifd workers. > * > - * 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. Yes, although I wonder if we should keep documenting this when we only call this function for a single page and it always returns at most 1. > * > * @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(RAMState *rs, PageSearchStatus *pss) > { > ram_addr_t offset = ((ram_addr_t)pss->page) << TARGET_PAGE_BITS; > int res; > > + if (!migrate_multifd() > + || migrate_zero_page_detection() == ZERO_PAGE_DETECTION_LEGACY) { > + if (save_zero_page(rs, pss, offset)) { > + return 1; > + } > + } > + > + if (migrate_multifd() && !migration_in_postcopy()) { > + RAMBlock *block = pss->block; > + return ram_save_multifd_page(block, offset); > + } > + > if (control_save_page(pss, offset, &res)) { > return res; > } > > - if (save_zero_page(rs, pss, offset)) { > - return 1; > - } > - > 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) > { > @@ -2121,7 +2098,7 @@ static int ram_save_host_page_urgent(PageSearchStatus > *pss) > > if (page_dirty) { > /* Be strict to return code; it must be 1, or what else? */ ... this^ comment, for instance. > - if (migration_ops->ram_save_target_page(rs, pss) != 1) { > + if (ram_save_target_page(rs, pss) != 1) { > error_report_once("%s: ram_save_target_page failed", > __func__); > ret = -1; > goto out; > @@ -2190,7 +2167,7 @@ static int ram_save_host_page(RAMState *rs, > PageSearchStatus *pss) > if (preempt_active) { > qemu_mutex_unlock(&rs->bitmap_mutex); > } > - tmppages = migration_ops->ram_save_target_page(rs, pss); > + tmppages = ram_save_target_page(rs, pss); > if (tmppages >= 0) { > pages += tmppages; > /* > @@ -2388,8 +2365,6 @@ static void ram_save_cleanup(void *opaque) > xbzrle_cleanup(); > multifd_ram_save_cleanup(); > ram_state_cleanup(rsp); > - g_free(migration_ops); > - migration_ops = NULL; > } > > static void ram_state_reset(RAMState *rs) > @@ -3055,13 +3030,8 @@ static int ram_save_setup(QEMUFile *f, void *opaque, > Error **errp) > return ret; > } > > - migration_ops = g_malloc0(sizeof(MigrationOps)); > - > 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();
