search for: balloon_get_free_pag

...cu->unsentmap = bitmap_new(ram_bitmap_pages); @@ -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) { +...

...mutex_lock(&vb->balloon_lock); > + while (pfn < max_pfn) { > + memset(vb->page_bitmap, 0, vb->bmap_len); > + ret = get_free_pages(pfn, pfn + vb->pfn_limit, > + vb->page_bitmap, vb->bmap_len * BITS_PER_BYTE); > + hdr->cmd = cpu_to_virtio16(vb->vdev, BALLOON_GET_FREE_PAGES); > + hdr->page_shift = cpu_to_virtio16(vb->vdev, PAGE_SHIFT); > + hdr->req_id = cpu_to_virtio64(vb->vdev, req_id); > + hdr->start_pfn = cpu_to_virtio64(vb->vdev, pfn); > + bmap_len = vb->pfn_limit / BITS_PER_BYTE; > + if (!ret) { > + hdr->flag = c...

...mutex_lock(&vb->balloon_lock); > + while (pfn < max_pfn) { > + memset(vb->page_bitmap, 0, vb->bmap_len); > + ret = get_free_pages(pfn, pfn + vb->pfn_limit, > + vb->page_bitmap, vb->bmap_len * BITS_PER_BYTE); > + hdr->cmd = cpu_to_virtio16(vb->vdev, BALLOON_GET_FREE_PAGES); > + hdr->page_shift = cpu_to_virtio16(vb->vdev, PAGE_SHIFT); > + hdr->req_id = cpu_to_virtio64(vb->vdev, req_id); > + hdr->start_pfn = cpu_to_virtio64(vb->vdev, pfn); > + bmap_len = vb->pfn_limit / BITS_PER_BYTE; > + if (!ret) { > + hdr->flag = c...

...ons(-) > > @@ -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_pag...

...deletions(-) > @@ -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_pag...

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

...x_pfn = get_max_pfn(); + mutex_lock(&vb->balloon_lock); + while (pfn < max_pfn) { + memset(vb->page_bitmap, 0, vb->bmap_len); + ret = get_free_pages(pfn, pfn + vb->pfn_limit, + vb->page_bitmap, vb->bmap_len * BITS_PER_BYTE); + hdr->cmd = cpu_to_virtio16(vb->vdev, BALLOON_GET_FREE_PAGES); + hdr->page_shift = cpu_to_virtio16(vb->vdev, PAGE_SHIFT); + hdr->req_id = cpu_to_virtio64(vb->vdev, req_id); + hdr->start_pfn = cpu_to_virtio64(vb->vdev, pfn); + bmap_len = vb->pfn_limit / BITS_PER_BYTE; + if (!ret) { + hdr->flag = cpu_to_virtio16(vb->vdev, +...

...oid qmp_balloon(int64_t target, Error **errp) > 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; > + } > + >...

...balloon_opaque = NULL; } @@ -116,3 +122,23 @@ void qmp_balloon(int64_t target, Error **errp) 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, +...

..._lock); > > + while (pfn < max_pfn) { > > + memset(vb->page_bitmap, 0, vb->bmap_len); > > + ret = get_free_pages(pfn, pfn + vb->pfn_limit, > > + vb->page_bitmap, vb->bmap_len * BITS_PER_BYTE); > > + hdr->cmd = cpu_to_virtio16(vb->vdev, > BALLOON_GET_FREE_PAGES); > > + hdr->page_shift = cpu_to_virtio16(vb->vdev, PAGE_SHIFT); > > + hdr->req_id = cpu_to_virtio64(vb->vdev, req_id); > > + hdr->start_pfn = cpu_to_virtio64(vb->vdev, pfn); > > + bmap_len = vb->pfn_limit / BITS_PER_BYTE; > > + if (!ret) {...

This patchset is for kernel and contains two parts of change to the virtio-balloon. One is the change for speeding up the inflating & deflating process, the main idea of this optimization is to use bitmap to send the page information to host instead of the PFNs, to reduce the overhead of virtio data transmission, address translation and madvise(). This can help to improve the performance by

This patchset is for kernel and contains two parts of change to the virtio-balloon. One is the change for speeding up the inflating & deflating process, the main idea of this optimization is to use bitmap to send the page information to host instead of the PFNs, to reduce the overhead of virtio data transmission, address translation and madvise(). This can help to improve the performance by

This patch set contains two parts of changes to the virtio-balloon. One is the change for speeding up the inflating & deflating process, the main idea of this optimization is to use bitmap to send the page information to host instead of the PFNs, to reduce the overhead of virtio data transmission, address translation and madvise(). This can help to improve the performance by about 85%.

This patch set contains two parts of changes to the virtio-balloon. One is the change for speeding up the inflating & deflating process, the main idea of this optimization is to use bitmap to send the page information to host instead of the PFNs, to reduce the overhead of virtio data transmission, address translation and madvise(). This can help to improve the performance by about 85%.