search for: extend_page_bitmap

...last_pfn, nr_pfn; > + struct virtqueue *vq = vb->req_vq; > + struct virtio_balloon_resp_hdr *hdr = vb->resp_hdr; > + int ret = 1, used_nr_bmap = 0, i; > + > + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_PAGE_BITMAP) && > + vb->nr_page_bmap == 1) > + extend_page_bitmap(vb); > + > + pfn_limit = PFNS_PER_BMAP * vb->nr_page_bmap; > + mutex_lock(&vb->balloon_lock); > + last_pfn = get_max_pfn(); > + > + while (ret) { > + clear_page_bitmap(vb); > + ret = get_unused_pages(pfn, pfn + pfn_limit, vb->page_bitmap, > + PFNS_PER_BM...

...last_pfn, nr_pfn; > + struct virtqueue *vq = vb->req_vq; > + struct virtio_balloon_resp_hdr *hdr = vb->resp_hdr; > + int ret = 1, used_nr_bmap = 0, i; > + > + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_PAGE_BITMAP) && > + vb->nr_page_bmap == 1) > + extend_page_bitmap(vb); > + > + pfn_limit = PFNS_PER_BMAP * vb->nr_page_bmap; > + mutex_lock(&vb->balloon_lock); > + last_pfn = get_max_pfn(); > + > + while (ret) { > + clear_page_bitmap(vb); > + ret = get_unused_pages(pfn, pfn + pfn_limit, vb->page_bitmap, > + PFNS_PER_BM...

...rtqueue *vq = vb->req_vq; > > + struct virtio_balloon_resp_hdr *hdr = vb->resp_hdr; > > + int ret = 1, used_nr_bmap = 0, i; > > + > > + if (virtio_has_feature(vb->vdev, > VIRTIO_BALLOON_F_PAGE_BITMAP) && > > + vb->nr_page_bmap == 1) > > + extend_page_bitmap(vb); > > + > > + pfn_limit = PFNS_PER_BMAP * vb->nr_page_bmap; > > + mutex_lock(&vb->balloon_lock); > > + last_pfn = get_max_pfn(); > > + > > + while (ret) { > > + clear_page_bitmap(vb); > > + ret = get_unused_pages(pfn, pfn + pfn_limit, v...

.../ > wait_event(vb->acked, virtqueue_get_buf(vq, &len)); > @@ -138,13 +199,93 @@ static void set_page_pfns(struct virtio_balloon *vb, > page_to_balloon_pfn(page) + i); > } > > -static unsigned fill_balloon(struct virtio_balloon *vb, size_t num) > +static void extend_page_bitmap(struct virtio_balloon *vb) > +{ > + int i; > + unsigned long bmap_len, bmap_count; > + > + bmap_len = ALIGN(get_max_pfn(), BITS_PER_LONG) / BITS_PER_BYTE; > + bmap_count = bmap_len / BALLOON_BMAP_SIZE; > + if (bmap_len % BALLOON_BMAP_SIZE) > + bmap_count++; > + if (bmap_...

.../ > wait_event(vb->acked, virtqueue_get_buf(vq, &len)); > @@ -138,13 +199,93 @@ static void set_page_pfns(struct virtio_balloon *vb, > page_to_balloon_pfn(page) + i); > } > > -static unsigned fill_balloon(struct virtio_balloon *vb, size_t num) > +static void extend_page_bitmap(struct virtio_balloon *vb) > +{ > + int i; > + unsigned long bmap_len, bmap_count; > + > + bmap_len = ALIGN(get_max_pfn(), BITS_PER_LONG) / BITS_PER_BYTE; > + bmap_count = bmap_len / BALLOON_BMAP_SIZE; > + if (bmap_len % BALLOON_BMAP_SIZE) > + bmap_count++; > + if (bmap_...

...The bottom-level lists have tens of thousands of pages in them, even on my >> laptop. Only 1/256 of these pages will get consumed in a given pass. >> > Your description is not exactly. > A 32k bitmap is used only when there is few free memory left in the system and when > the extend_page_bitmap() failed to allocate more memory for the bitmap. Or dozens of > 32k split bitmap will be used, this version limit the bitmap count to 32, it means we can use > at most 32*32 kB for the bitmap, which can cover 128GB for RAM. We can increase the bitmap > count limit to a larger value if 32...

...The bottom-level lists have tens of thousands of pages in them, even on my >> laptop. Only 1/256 of these pages will get consumed in a given pass. >> > Your description is not exactly. > A 32k bitmap is used only when there is few free memory left in the system and when > the extend_page_bitmap() failed to allocate more memory for the bitmap. Or dozens of > 32k split bitmap will be used, this version limit the bitmap count to 32, it means we can use > at most 32*32 kB for the bitmap, which can cover 128GB for RAM. We can increase the bitmap > count limit to a larger value if 32...

...on *vb, >> + struct page *page) >> +{ >> + unsigned long balloon_pfn = page_to_balloon_pfn(page); >> + >> + vb->min_pfn = min(balloon_pfn, vb->min_pfn); >> + vb->max_pfn = max(balloon_pfn, vb->max_pfn); >> +} >> + >> +static void extend_page_bitmap(struct virtio_balloon *vb, >> + unsigned long nr_pfn) > > what exactly does this do? By default, only one page_bmap is allocated. When there are too many pfns to fit into one page_bmap, it tries to allocate more page_bmap using this extend_page_bmap() function. > >> +{ &gt...

...r, this completes via balloon_ack */ wait_event(vb->acked, virtqueue_get_buf(vq, &len)); @@ -138,13 +199,93 @@ static void set_page_pfns(struct virtio_balloon *vb, page_to_balloon_pfn(page) + i); } -static unsigned fill_balloon(struct virtio_balloon *vb, size_t num) +static void extend_page_bitmap(struct virtio_balloon *vb) +{ + int i; + unsigned long bmap_len, bmap_count; + + bmap_len = ALIGN(get_max_pfn(), BITS_PER_LONG) / BITS_PER_BYTE; + bmap_count = bmap_len / BALLOON_BMAP_SIZE; + if (bmap_len % BALLOON_BMAP_SIZE) + bmap_count++; + if (bmap_count > BALLOON_BMAP_COUNT) + bmap_count...

...r, this completes via balloon_ack */ wait_event(vb->acked, virtqueue_get_buf(vq, &len)); @@ -138,13 +199,93 @@ static void set_page_pfns(struct virtio_balloon *vb, page_to_balloon_pfn(page) + i); } -static unsigned fill_balloon(struct virtio_balloon *vb, size_t num) +static void extend_page_bitmap(struct virtio_balloon *vb) +{ + int i; + unsigned long bmap_len, bmap_count; + + bmap_len = ALIGN(get_max_pfn(), BITS_PER_LONG) / BITS_PER_BYTE; + bmap_count = bmap_len / BALLOON_BMAP_SIZE; + if (bmap_len % BALLOON_BMAP_SIZE) + bmap_count++; + if (bmap_count > BALLOON_BMAP_COUNT) + bmap_count...

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%.

...e_bmap_pfn_range(struct virtio_balloon *vb, > + struct page *page) > +{ > + unsigned long balloon_pfn = page_to_balloon_pfn(page); > + > + vb->min_pfn = min(balloon_pfn, vb->min_pfn); > + vb->max_pfn = max(balloon_pfn, vb->max_pfn); > +} > + > +static void extend_page_bitmap(struct virtio_balloon *vb, > + unsigned long nr_pfn) what exactly does this do? > +{ > + int i, bmap_count; > + unsigned long bmap_len; > + > + bmap_len = ALIGN(nr_pfn, BITS_PER_LONG) / BITS_PER_BYTE; > + bmap_len = ALIGN(bmap_len, PAGE_BMAP_SIZE); > + bmap_count = min...

...e_bmap_pfn_range(struct virtio_balloon *vb, > + struct page *page) > +{ > + unsigned long balloon_pfn = page_to_balloon_pfn(page); > + > + vb->min_pfn = min(balloon_pfn, vb->min_pfn); > + vb->max_pfn = max(balloon_pfn, vb->max_pfn); > +} > + > +static void extend_page_bitmap(struct virtio_balloon *vb, > + unsigned long nr_pfn) what exactly does this do? > +{ > + int i, bmap_count; > + unsigned long bmap_len; > + > + bmap_len = ALIGN(nr_pfn, BITS_PER_LONG) / BITS_PER_BYTE; > + bmap_len = ALIGN(bmap_len, PAGE_BMAP_SIZE); > + bmap_count = min...

...t;max_pfn = 0; +} + +static inline void update_bmap_pfn_range(struct virtio_balloon *vb, + struct page *page) +{ + unsigned long balloon_pfn = page_to_balloon_pfn(page); + + vb->min_pfn = min(balloon_pfn, vb->min_pfn); + vb->max_pfn = max(balloon_pfn, vb->max_pfn); +} + +static void extend_page_bitmap(struct virtio_balloon *vb, + unsigned long nr_pfn) +{ + int i, bmap_count; + unsigned long bmap_len; + + bmap_len = ALIGN(nr_pfn, BITS_PER_LONG) / BITS_PER_BYTE; + bmap_len = ALIGN(bmap_len, BALLOON_BMAP_SIZE); + bmap_count = min((int)(bmap_len / BALLOON_BMAP_SIZE), + BALLOON_BMAP_COUNT); +...

...ave tens of thousands of pages in them, even > >> on my laptop. Only 1/256 of these pages will get consumed in a given pass. > >> > > Your description is not exactly. > > A 32k bitmap is used only when there is few free memory left in the > > system and when the extend_page_bitmap() failed to allocate more > > memory for the bitmap. Or dozens of 32k split bitmap will be used, > > this version limit the bitmap count to 32, it means we can use at most > > 32*32 kB for the bitmap, which can cover 128GB for RAM. We can increase > the bitmap count limit to a...

...t;max_pfn = 0; +} + +static inline void update_bmap_pfn_range(struct virtio_balloon *vb, + struct page *page) +{ + unsigned long balloon_pfn = page_to_balloon_pfn(page); + + vb->min_pfn = min(balloon_pfn, vb->min_pfn); + vb->max_pfn = max(balloon_pfn, vb->max_pfn); +} + +static void extend_page_bitmap(struct virtio_balloon *vb, + unsigned long nr_pfn) +{ + int i, bmap_count; + unsigned long bmap_len; + + bmap_len = ALIGN(nr_pfn, BITS_PER_LONG) / BITS_PER_BYTE; + bmap_len = ALIGN(bmap_len, PAGE_BMAP_SIZE); + bmap_count = min((int)(bmap_len / PAGE_BMAP_SIZE), + PAGE_BMAP_COUNT_MAX); + + for...

...long pfn = 0, bmap_len, pfn_limit, last_pfn, nr_pfn; + struct virtqueue *vq = vb->req_vq; + struct virtio_balloon_resp_hdr *hdr = vb->resp_hdr; + int ret = 1, used_nr_bmap = 0, i; + + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_PAGE_BITMAP) && + vb->nr_page_bmap == 1) + extend_page_bitmap(vb); + + pfn_limit = PFNS_PER_BMAP * vb->nr_page_bmap; + mutex_lock(&vb->balloon_lock); + last_pfn = get_max_pfn(); + + while (ret) { + clear_page_bitmap(vb); + ret = get_unused_pages(pfn, pfn + pfn_limit, vb->page_bitmap, + PFNS_PER_BMAP, vb->nr_page_bmap); + if (ret < 0)...

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%.