search for: bmap_hdr

...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?

...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?

...ts(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 + vb->pfn_limit, + vb->page_bitmap, vb->bmap_len * BITS_PER_BYTE);...

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

..._device *vdev; > struct virtqueue *inflate_vq, *deflate_vq, *stats_vq; > @@ -62,6 +80,15 @@ struct virtio_balloon { > > /* Number of balloon pages we've told the Host we're not using. */ > unsigned int num_pages; > + /* Pointer of the bitmap header. */ > + void *bmap_hdr; > + /* Bitmap and length used to tell the host the pages */ > + unsigned long *page_bitmap; > + unsigned long bmap_len; > + /* Pfn limit */ > + unsigned long pfn_limit; > + /* Used to record the processed pfn range */ > + unsigned long min_pfn, max_pfn, start_pfn, end_pfn; &gt...

..._device *vdev; > struct virtqueue *inflate_vq, *deflate_vq, *stats_vq; > @@ -62,6 +80,15 @@ struct virtio_balloon { > > /* Number of balloon pages we've told the Host we're not using. */ > unsigned int num_pages; > + /* Pointer of the bitmap header. */ > + void *bmap_hdr; > + /* Bitmap and length used to tell the host the pages */ > + unsigned long *page_bitmap; > + unsigned long bmap_len; > + /* Pfn limit */ > + unsigned long pfn_limit; > + /* Used to record the processed pfn range */ > + unsigned long min_pfn, max_pfn, start_pfn, end_pfn; &gt...

...)); > } > > +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...

...)); > } > > +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...

...param(oom_pages, int, S_IRUSR | S_IWUSR); MODULE_PARM_DESC(oom_pages, "pages to free on OOM"); @@ -67,6 +71,13 @@ struct virtio_balloon { /* Number of balloon pages we've told the Host we're not using. */ unsigned int num_pages; + /* Pointer of the bitmap header. */ + void *bmap_hdr; + /* Bitmap and bitmap count used to tell the host the pages */ + unsigned long *page_bitmap[BALLOON_BMAP_COUNT]; + unsigned int nr_page_bmap; + /* Used to record the processed pfn range */ + unsigned long min_pfn, max_pfn, start_pfn, end_pfn; /* * The pages we've told the Host we're...

...param(oom_pages, int, S_IRUSR | S_IWUSR); MODULE_PARM_DESC(oom_pages, "pages to free on OOM"); @@ -67,6 +71,13 @@ struct virtio_balloon { /* Number of balloon pages we've told the Host we're not using. */ unsigned int num_pages; + /* Pointer of the bitmap header. */ + void *bmap_hdr; + /* Bitmap and bitmap count used to tell the host the pages */ + unsigned long *page_bitmap[BALLOON_BMAP_COUNT]; + unsigned int nr_page_bmap; + /* Used to record the processed pfn range */ + unsigned long min_pfn, max_pfn, start_pfn, end_pfn; /* * The pages we've told the Host we're...

...ct virtio_balloon { struct virtio_device *vdev; struct virtqueue *inflate_vq, *deflate_vq, *stats_vq; @@ -62,6 +80,15 @@ struct virtio_balloon { /* Number of balloon pages we've told the Host we're not using. */ unsigned int num_pages; + /* Pointer of the bitmap header. */ + void *bmap_hdr; + /* Bitmap and length used to tell the host the pages */ + unsigned long *page_bitmap; + unsigned long bmap_len; + /* Pfn limit */ + unsigned long pfn_limit; + /* Used to record the processed pfn range */ + unsigned long min_pfn, max_pfn, start_pfn, end_pfn; /* * The pages we've told the...

...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...

...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...

..._device *vdev; > struct virtqueue *inflate_vq, *deflate_vq, *stats_vq; > @@ -62,6 +80,15 @@ struct virtio_balloon { > > /* Number of balloon pages we've told the Host we're not using. */ > unsigned int num_pages; > + /* Pointer of the bitmap header. */ > + void *bmap_hdr; > + /* Bitmap and length used to tell the host the pages */ > + unsigned long *page_bitmap; > + unsigned long bmap_len; > + /* Pfn limit */ > + unsigned long pfn_limit; > + /* Used to record the processed pfn range */ > + unsigned long min_pfn, max_pfn, start_pfn, end_pfn; &gt...

..._device *vdev; > struct virtqueue *inflate_vq, *deflate_vq, *stats_vq; > @@ -62,6 +80,15 @@ struct virtio_balloon { > > /* Number of balloon pages we've told the Host we're not using. */ > unsigned int num_pages; > + /* Pointer of the bitmap header. */ > + void *bmap_hdr; > + /* Bitmap and length used to tell the host the pages */ > + unsigned long *page_bitmap; > + unsigned long bmap_len; > + /* Pfn limit */ > + unsigned long pfn_limit; > + /* Used to record the processed pfn range */ > + unsigned long min_pfn, max_pfn, start_pfn, end_pfn; &gt...

...WUSR); > MODULE_PARM_DESC(oom_pages, "pages to free on OOM"); > @@ -67,6 +71,13 @@ struct virtio_balloon { > > /* Number of balloon pages we've told the Host we're not using. */ > unsigned int num_pages; > + /* Pointer of the bitmap header. */ > + void *bmap_hdr; > + /* Bitmap and bitmap count used to tell the host the pages */ > + unsigned long *page_bitmap[BALLOON_BMAP_COUNT]; > + unsigned int nr_page_bmap; > + /* Used to record the processed pfn range */ > + unsigned long min_pfn, max_pfn, start_pfn, end_pfn; > /* > * The pages...

...WUSR); > MODULE_PARM_DESC(oom_pages, "pages to free on OOM"); > @@ -67,6 +71,13 @@ struct virtio_balloon { > > /* Number of balloon pages we've told the Host we're not using. */ > unsigned int num_pages; > + /* Pointer of the bitmap header. */ > + void *bmap_hdr; > + /* Bitmap and bitmap count used to tell the host the pages */ > + unsigned long *page_bitmap[BALLOON_BMAP_COUNT]; > + unsigned int nr_page_bmap; > + /* Used to record the processed pfn range */ > + unsigned long min_pfn, max_pfn, start_pfn, end_pfn; > /* > * The pages...

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%.