search for: balloon_bmap_hdr

...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 the pfn buffer before?

...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 the pfn buffer before?

...end page info with bitmap */ > > /* Size of a PFN in the balloon interface. */ > #define VIRTIO_BALLOON_PFN_SHIFT 12 > @@ -82,4 +83,22 @@ struct virtio_balloon_stat { > __virtio64 val; > } __attribute__((packed)); > > +/* Page bitmap header structure */ > +struct balloon_bmap_hdr { > + /* Used to distinguish different request */ > + __virtio16 cmd; > + /* Shift width of page in the bitmap */ > + __virtio16 page_shift; > + /* flag used to identify different status */ > + __virtio16 flag; > + /* Reserved */ > + __virtio16 reserved; > + /* ID of the...

...end page info with bitmap */ > > /* Size of a PFN in the balloon interface. */ > #define VIRTIO_BALLOON_PFN_SHIFT 12 > @@ -82,4 +83,22 @@ struct virtio_balloon_stat { > __virtio64 val; > } __attribute__((packed)); > > +/* Page bitmap header structure */ > +struct balloon_bmap_hdr { > + /* Used to distinguish different request */ > + __virtio16 cmd; > + /* Shift width of page in the bitmap */ > + __virtio16 page_shift; > + /* flag used to identify different status */ > + __virtio16 flag; > + /* Reserved */ > + __virtio16 reserved; > + /* ID of the...

..._host(struct virtio_balloon *vb, struct virtqueue *vq) > { > struct scatterlist sg; > unsigned int len; > > - sg_init_one(&sg, vb->pfns, sizeof(vb->pfns[0]) * vb->num_pfns); > + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_PAGE_BITMAP)) { > + struct balloon_bmap_hdr *hdr = vb->bmap_hdr; > + unsigned long bmap_len; > + > + /* cmd and req_id are not used here, set them to 0 */ > + hdr->cmd = cpu_to_virtio16(vb->vdev, 0); > + hdr->page_shift = cpu_to_virtio16(vb->vdev, PAGE_SHIFT); > + hdr->reserved = cpu_to_virtio16(vb-&g...

..._host(struct virtio_balloon *vb, struct virtqueue *vq) > { > struct scatterlist sg; > unsigned int len; > > - sg_init_one(&sg, vb->pfns, sizeof(vb->pfns[0]) * vb->num_pfns); > + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_PAGE_BITMAP)) { > + struct balloon_bmap_hdr *hdr = vb->bmap_hdr; > + unsigned long bmap_len; > + > + /* cmd and req_id are not used here, set them to 0 */ > + hdr->cmd = cpu_to_virtio16(vb->vdev, 0); > + hdr->page_shift = cpu_to_virtio16(vb->vdev, PAGE_SHIFT); > + hdr->reserved = cpu_to_virtio16(vb-&g...

...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 the pfn buffer before? > > > Yes I would limit this to 1G memory in a go, will result in a 32K...

...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 the pfn buffer before? > > > Yes I would limit this to 1G memory in a go, will result in a 32K...

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%.

...vailable)); > } > > +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_len); > + ret = get_free_pages(pfn, pfn + vb->pfn_limit, > + vb->page_bi...

...vailable)); > } > > +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_len); > + ret = get_free_pages(pfn, pfn + vb->pfn_limit, > + vb->page_bi...

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

...st(struct virtio_balloon *vb, struct virtqueue *vq) > { > - 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;...

...st(struct virtio_balloon *vb, struct virtqueue *vq) > { > - 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;...

...s the reason for this selection. > > Still applies here. > I will add the comment for this. > > - sg_init_one(&sg, vb->pfns, sizeof(vb->pfns[0]) * vb->num_pfns); > > + if (virtio_has_feature(vb->vdev, > VIRTIO_BALLOON_F_PAGE_BITMAP)) { > > + struct balloon_bmap_hdr *hdr = vb->bmap_hdr; > > + unsigned long bmap_len; > > + > > + /* cmd and req_id are not used here, set them to 0 */ > > + hdr->cmd = cpu_to_virtio16(vb->vdev, 0); > > + hdr->page_shift = cpu_to_virtio16(vb->vdev, PAGE_SHIFT); > > + hdr->re...

...gt; Still applies here. > > > > I will add the comment for this. > > > > - sg_init_one(&sg, vb->pfns, sizeof(vb->pfns[0]) * vb->num_pfns); > > > + if (virtio_has_feature(vb->vdev, > > VIRTIO_BALLOON_F_PAGE_BITMAP)) { > > > + struct balloon_bmap_hdr *hdr = vb->bmap_hdr; > > > + unsigned long bmap_len; > > > + > > > + /* cmd and req_id are not used here, set them to 0 */ > > > + hdr->cmd = cpu_to_virtio16(vb->vdev, 0); > > > + hdr->page_shift = cpu_to_virtio16(vb->vdev, PAGE_SHIFT)...

...gt; Still applies here. > > > > I will add the comment for this. > > > > - sg_init_one(&sg, vb->pfns, sizeof(vb->pfns[0]) * vb->num_pfns); > > > + if (virtio_has_feature(vb->vdev, > > VIRTIO_BALLOON_F_PAGE_BITMAP)) { > > > + struct balloon_bmap_hdr *hdr = vb->bmap_hdr; > > > + unsigned long bmap_len; > > > + > > > + /* cmd and req_id are not used here, set them to 0 */ > > > + hdr->cmd = cpu_to_virtio16(vb->vdev, 0); > > > + hdr->page_shift = cpu_to_virtio16(vb->vdev, PAGE_SHIFT)...

...= balloon_pfn; +} + static void tell_host(struct virtio_balloon *vb, struct virtqueue *vq) { - 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; + +...