search for: migration_bitmap_rcu

...pages that haven't been sent even once * only maintained and used in postcopy at the moment * where it's used to send the dirtymap at the start @@ -561,12 +563,7 @@ ram_addr_t migration_bitmap_find_dirty(RAMBlock *rb, unsigned long next; bitmap = atomic_rcu_read(&migration_bitmap_rcu)->bmap; - if (ram_bulk_stage && nr > base) { - next = nr + 1; - } else { - next = find_next_bit(bitmap, size, nr); - } - + next = find_next_bit(bitmap, size, nr); *ram_addr_abs = next << TARGET_PAGE_BITS; return (next - base) << TARGET_P...

The current QEMU live migration implementation mark the all the guest's RAM pages as dirtied in the ram bulk stage, all these pages will be processed and that takes quit a lot of CPU cycles. >From guest's point of view, it doesn't care about the content in free pages. We can make use of this fact and skip processing the free pages in the ram bulk stage, it can save a lot CPU cycles

The current QEMU live migration implementation mark the all the guest's RAM pages as dirtied in the ram bulk stage, all these pages will be processed and that takes quit a lot of CPU cycles. >From guest's point of view, it doesn't care about the content in free pages. We can make use of this fact and skip processing the free pages in the ram bulk stage, it can save a lot CPU cycles

...1945,6 +1971,20 @@ static int ram_save_setup(QEMUFile *f, void *opaque) > DIRTY_MEMORY_MIGRATION); > } > memory_global_dirty_log_start(); > + > + if (balloon_free_pages_support() && > + balloon_get_free_pages(migration_bitmap_rcu->free_pages_bmap, > + &free_pages_count) == 0) { > + qemu_mutex_unlock_iothread(); > + while (balloon_get_free_pages(migration_bitmap_rcu->free_pages_bmap, > + &free_pages_count) == 0) { >...

...1945,6 +1971,20 @@ static int ram_save_setup(QEMUFile *f, void *opaque) > DIRTY_MEMORY_MIGRATION); > } > memory_global_dirty_log_start(); > + > + if (balloon_free_pages_support() && > + balloon_get_free_pages(migration_bitmap_rcu->free_pages_bmap, > + &free_pages_count) == 0) { > + qemu_mutex_unlock_iothread(); > + while (balloon_get_free_pages(migration_bitmap_rcu->free_pages_bmap, > + &free_pages_count) == 0) { >...