search for: free_pages_count

...balloon_event_fn(balloon_opaque, target); > } > + > +bool balloon_free_pages_support(void) > +{ > + return balloon_free_pages_fn ? true : false; > +} > + > +int balloon_get_free_pages(unsigned long *free_pages_bitmap, > + unsigned long *free_pages_count) > +{ > + if (!balloon_free_pages_fn) { > + return -1; > + } > + > + if (!free_pages_bitmap || !free_pages_count) { > + return -1; > + } > + > + return balloon_free_pages_fn(balloon_opaque, > + free_pages_...

...trace_balloon_event(balloon_opaque, target); balloon_event_fn(balloon_opaque, target); } + +bool balloon_free_pages_support(void) +{ + return balloon_free_pages_fn ? true : false; +} + +int balloon_get_free_pages(unsigned long *free_pages_bitmap, + unsigned long *free_pages_count) +{ + if (!balloon_free_pages_fn) { + return -1; + } + + if (!free_pages_bitmap || !free_pages_count) { + return -1; + } + + return balloon_free_pages_fn(balloon_opaque, + free_pages_bitmap, free_pages_count); + } diff --git a/hw/virtio/v...

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

...save_iterate and ram_save_complete has * long-running RCU critical section. When rcu-reclaims in the code @@ -1884,6 +1906,7 @@ static int ram_save_setup(QEMUFile *f, void *opaque) { RAMBlock *block; int64_t ram_bitmap_pages; /* Size of bitmap in pages, including gaps */ + uint64_t free_pages_count = 0; dirty_rate_high_cnt = 0; bitmap_sync_count = 0; @@ -1931,6 +1954,9 @@ static int ram_save_setup(QEMUFile *f, void *opaque) ram_bitmap_pages = last_ram_offset() >> TARGET_PAGE_BITS; migration_bitmap_rcu = g_new0(struct BitmapRcu, 1); migration_bitmap_rcu->bma...

...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) { > + usleep(1000); > + } > + qemu_mutex_lock_iothrea...

...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) { > + usleep(1000); > + } > + qemu_mutex_lock_iothrea...

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

.../sysemu/balloon.h | 10 ++- > 5 files changed, 134 insertions(+), 5 deletions(-) > +static int virtio_balloon_free_pages(void *opaque, > + unsigned long *free_pages_bitmap, > + unsigned long *free_pages_count) > +{ > + VirtIOBalloon *s = opaque; > + VirtIODevice *vdev = VIRTIO_DEVICE(s); > + VirtQueueElement *elem = s->free_pages_vq_elem; > + int len; > + > + if (!balloon_free_pages_supported(s)) { > + return -1; > + } > + > + if (s->req...