search for: bmap_len

...init_one(&sg, vb->pfns, sizeof(vb->pfns[0]) * vb->num_pfns); > > > > + if (virtio_has_feature(vb->vdev, > > > VIRTIO_BALLOON_F_PAGE_BITMAP)) { > > > > + u32 page_shift = PAGE_SHIFT; > > > > + unsigned long start_pfn, end_pfn, flags = 0, bmap_len; > > > > + struct scatterlist sg[5]; > > > > + > > > > + start_pfn = rounddown(vb->start_pfn, BITS_PER_LONG); > > > > + end_pfn = roundup(vb->end_pfn, BITS_PER_LONG); > > > > + bmap_len = (end_pfn - start_pfn) / BITS_PER_LONG * &...

...init_one(&sg, vb->pfns, sizeof(vb->pfns[0]) * vb->num_pfns); > > > > + if (virtio_has_feature(vb->vdev, > > > VIRTIO_BALLOON_F_PAGE_BITMAP)) { > > > > + u32 page_shift = PAGE_SHIFT; > > > > + unsigned long start_pfn, end_pfn, flags = 0, bmap_len; > > > > + struct scatterlist sg[5]; > > > > + > > > > + start_pfn = rounddown(vb->start_pfn, BITS_PER_LONG); > > > > + end_pfn = roundup(vb->end_pfn, BITS_PER_LONG); > > > > + bmap_len = (end_pfn - start_pfn) / BITS_PER_LONG * &...

...void update_balloon_stats(struct virtio_balloon *vb) > pages_to_bytes(available)); > } > > +static void update_free_pages_stats(struct virtio_balloon *vb, why _stats? > + unsigned long req_id) > +{ > + struct scatterlist sg_in, sg_out; > + unsigned long pfn = 0, bmap_len, max_pfn; > + struct virtqueue *vq = vb->misc_vq; > + struct balloon_bmap_hdr *hdr = vb->bmap_hdr; > + int ret = 1; > + > + max_pfn = get_max_pfn(); > + mutex_lock(&vb->balloon_lock); > + while (pfn < max_pfn) { > + memset(vb->page_bitmap, 0, vb->bmap_...

...void update_balloon_stats(struct virtio_balloon *vb) > pages_to_bytes(available)); > } > > +static void update_free_pages_stats(struct virtio_balloon *vb, why _stats? > + unsigned long req_id) > +{ > + struct scatterlist sg_in, sg_out; > + unsigned long pfn = 0, bmap_len, max_pfn; > + struct virtqueue *vq = vb->misc_vq; > + struct balloon_bmap_hdr *hdr = vb->bmap_hdr; > + int ret = 1; > + > + max_pfn = get_max_pfn(); > + mutex_lock(&vb->balloon_lock); > + while (pfn < max_pfn) { > + memset(vb->page_bitmap, 0, vb->bmap_...

...; > Sounds good, but you also need to limit by allocated bitmap size. Why should we limit the page bitmap size? Is it no good to send a large page bitmap? or to save the memory used for page bitmap? Or some other reason? > > > > > + unsigned long start_pfn, end_pfn, flags = 0, bmap_len; > > + struct scatterlist sg[5]; > > + > > + start_pfn = rounddown(vb->start_pfn, BITS_PER_LONG); > > + end_pfn = roundup(vb->end_pfn, BITS_PER_LONG); > > + bmap_len = (end_pfn - start_pfn) / BITS_PER_LONG * > sizeof(long); > > + > > + sg_init...

...; > Sounds good, but you also need to limit by allocated bitmap size. Why should we limit the page bitmap size? Is it no good to send a large page bitmap? or to save the memory used for page bitmap? Or some other reason? > > > > > + unsigned long start_pfn, end_pfn, flags = 0, bmap_len; > > + struct scatterlist sg[5]; > > + > > + start_pfn = rounddown(vb->start_pfn, BITS_PER_LONG); > > + end_pfn = roundup(vb->end_pfn, BITS_PER_LONG); > > + bmap_len = (end_pfn - start_pfn) / BITS_PER_LONG * > sizeof(long); > > + > > + sg_init...

..._device *vdev; struct virtqueue *inflate_vq, *deflate_vq, *stats_vq; @@ -62,6 +64,9 @@ struct virtio_balloon { /* Number of balloon pages we've told the Host we're not using. */ unsigned int num_pages; + unsigned long *page_bitmap; + unsigned long start_pfn, end_pfn; + unsigned long bmap_len; /* * The pages we've told the Host we're not using are enqueued * at vb_dev_info->pages list. @@ -111,15 +116,66 @@ static void balloon_ack(struct virtqueue *vq) wake_up(&vb->acked); } +static int balloon_page_bitmap_init(struct virtio_balloon *vb) +{ + unsigned long...

..._device *vdev; struct virtqueue *inflate_vq, *deflate_vq, *stats_vq; @@ -62,6 +64,9 @@ struct virtio_balloon { /* Number of balloon pages we've told the Host we're not using. */ unsigned int num_pages; + unsigned long *page_bitmap; + unsigned long start_pfn, end_pfn; + unsigned long bmap_len; /* * The pages we've told the Host we're not using are enqueued * at vb_dev_info->pages list. @@ -111,15 +116,66 @@ static void balloon_ack(struct virtqueue *vq) wake_up(&vb->acked); } +static int balloon_page_bitmap_init(struct virtio_balloon *vb) +{ + unsigned long...

...->pfns, sizeof(vb->pfns[0]) * vb->num_pfns); > > > > > + if (virtio_has_feature(vb->vdev, > > > > VIRTIO_BALLOON_F_PAGE_BITMAP)) { > > > > > + u32 page_shift = PAGE_SHIFT; > > > > > + unsigned long start_pfn, end_pfn, flags = 0, bmap_len; > > > > > + struct scatterlist sg[5]; > > > > > + > > > > > + start_pfn = rounddown(vb->start_pfn, BITS_PER_LONG); > > > > > + end_pfn = roundup(vb->end_pfn, BITS_PER_LONG); > > > > > + bmap_len = (end_pfn - start...

On 07/26/2016 06:23 PM, Liang Li wrote: > + vb->pfn_limit = VIRTIO_BALLOON_PFNS_LIMIT; > + vb->pfn_limit = min(vb->pfn_limit, get_max_pfn()); > + vb->bmap_len = ALIGN(vb->pfn_limit, BITS_PER_LONG) / > + BITS_PER_BYTE + 2 * sizeof(unsigned long); > + hdr_len = sizeof(struct balloon_bmap_hdr); > + vb->bmap_hdr = kzalloc(hdr_len + vb->bmap_len, GFP_KERNEL); This ends up doing a 1MB kmalloc() right? That seems a _bit_ big. How big was...

On 07/26/2016 06:23 PM, Liang Li wrote: > + vb->pfn_limit = VIRTIO_BALLOON_PFNS_LIMIT; > + vb->pfn_limit = min(vb->pfn_limit, get_max_pfn()); > + vb->bmap_len = ALIGN(vb->pfn_limit, BITS_PER_LONG) / > + BITS_PER_BYTE + 2 * sizeof(unsigned long); > + hdr_len = sizeof(struct balloon_bmap_hdr); > + vb->bmap_hdr = kzalloc(hdr_len + vb->bmap_len, GFP_KERNEL); This ends up doing a 1MB kmalloc() right? That seems a _bit_ big. How big was...

...q; @@ -62,6 +64,9 > > @@ struct virtio_balloon { > > > > /* Number of balloon pages we've told the Host we're not using. */ > > unsigned int num_pages; > > + unsigned long *page_bitmap; > > + unsigned long start_pfn, end_pfn; > > + unsigned long bmap_len; > > /* > > * The pages we've told the Host we're not using are enqueued > > * at vb_dev_info->pages list. > > @@ -111,15 +116,66 @@ static void balloon_ack(struct virtqueue *vq) > > wake_up(&vb->acked); > > } > > > > +sta...

...q; @@ -62,6 +64,9 > > @@ struct virtio_balloon { > > > > /* Number of balloon pages we've told the Host we're not using. */ > > unsigned int num_pages; > > + unsigned long *page_bitmap; > > + unsigned long start_pfn, end_pfn; > > + unsigned long bmap_len; > > /* > > * The pages we've told the Host we're not using are enqueued > > * at vb_dev_info->pages list. > > @@ -111,15 +116,66 @@ static void balloon_ack(struct virtqueue *vq) > > wake_up(&vb->acked); > > } > > > > +sta...

...} > > > > +static void update_free_pages_stats(struct virtio_balloon *vb, > > why _stats? Will change. > > + max_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); >...

..._dev_info->pages list. @@ -373,6 +378,49 @@ static void update_balloon_stats(struct virtio_balloon *vb) pages_to_bytes(available)); } +static void update_free_pages_stats(struct virtio_balloon *vb, + unsigned long req_id) +{ + struct scatterlist sg_in, sg_out; + unsigned long pfn = 0, bmap_len, max_pfn; + struct virtqueue *vq = vb->misc_vq; + struct balloon_bmap_hdr *hdr = vb->bmap_hdr; + int ret = 1; + + max_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 +...

...; - struct scatterlist sg; > - unsigned int len; > + struct scatterlist sg, sg2[BALLOON_BMAP_COUNT + 1]; > + unsigned int len, i; > + > + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_PAGE_BITMAP)) { > + struct balloon_bmap_hdr *hdr = vb->bmap_hdr; > + unsigned long bmap_len; > + int nr_pfn, nr_used_bmap, nr_buf; > + > + nr_pfn = vb->end_pfn - vb->start_pfn + 1; > + nr_pfn = roundup(nr_pfn, BITS_PER_LONG); > + nr_used_bmap = nr_pfn / PFNS_PER_BMAP; > + bmap_len = nr_pfn / BITS_PER_BYTE; > + nr_buf = nr_used_bmap + 1; > + > + /* c...

...; - struct scatterlist sg; > - unsigned int len; > + struct scatterlist sg, sg2[BALLOON_BMAP_COUNT + 1]; > + unsigned int len, i; > + > + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_PAGE_BITMAP)) { > + struct balloon_bmap_hdr *hdr = vb->bmap_hdr; > + unsigned long bmap_len; > + int nr_pfn, nr_used_bmap, nr_buf; > + > + nr_pfn = vb->end_pfn - vb->start_pfn + 1; > + nr_pfn = roundup(nr_pfn, BITS_PER_LONG); > + nr_used_bmap = nr_pfn / PFNS_PER_BMAP; > + bmap_len = nr_pfn / BITS_PER_BYTE; > + nr_buf = nr_used_bmap + 1; > + > + /* c...

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

...vb->resp_buf_size *= 2; What happens to the data in ->resp_data at this point? Doesn't this just throw it away? ... > +struct page_info_item { > + __le64 start_pfn : 52; /* start pfn for the bitmap */ > + __le64 page_shift : 6; /* page shift width, in bytes */ > + __le64 bmap_len : 6; /* bitmap length, in bytes */ > +}; Is 'bmap_len' too short? a 64-byte buffer is a bit tiny. Right? > +static int mark_unused_pages(struct zone *zone, > + unsigned long *unused_pages, unsigned long size, > + int order, unsigned long *pos) > +{ > + unsigned lon...