On 02/20/2012 11:34 AM, Prasad Joshi wrote:
Signed-off-by: Prasad Joshi<[email protected]>

This breaks compatibility with existing guests and more importantly, doesn't make any sense. There's no commit message explaining why 1MB is a better number than 4K, 2MB which I could at least understand as an alternative to 4K.

Regards,

Anthony Liguori

---
  drivers/virtio/virtio_balloon.c |   18 +++++++++---------
  include/linux/virtio_balloon.h  |    4 +++-
  2 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 95aeedf..e352448 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -64,9 +64,8 @@ static u32 page_to_balloon_pfn(struct page *page)
  {
        unsigned long pfn = page_to_pfn(page);

-       BUILD_BUG_ON(PAGE_SHIFT<  VIRTIO_BALLOON_PFN_SHIFT);
        /* Convert pfn from Linux page size to balloon page size. */
-       return pfn>>  (PAGE_SHIFT - VIRTIO_BALLOON_PFN_SHIFT);
+       return pfn>>  VIRTIO_BALLOON_PAGE_ORDER;
  }

  static void balloon_ack(struct virtqueue *vq)
@@ -102,8 +101,9 @@ static void fill_balloon(struct virtio_balloon *vb, size_t 
num)
        num = min(num, ARRAY_SIZE(vb->pfns));

        for (vb->num_pfns = 0; vb->num_pfns<  num; vb->num_pfns++) {
-               struct page *page = alloc_page(GFP_HIGHUSER | __GFP_NORETRY |
-                                       __GFP_NOMEMALLOC | __GFP_NOWARN);
+               struct page *page = alloc_pages(GFP_HIGHUSER | __GFP_NORETRY |
+                               __GFP_NOMEMALLOC | __GFP_NOWARN,
+                               VIRTIO_BALLOON_PAGE_ORDER);
                if (!page) {
                        if (printk_ratelimit())
                                dev_printk(KERN_INFO,&vb->vdev->dev,
@@ -114,7 +114,7 @@ static void fill_balloon(struct virtio_balloon *vb, size_t 
num)
                        break;
                }
                vb->pfns[vb->num_pfns] = page_to_balloon_pfn(page);
-               totalram_pages--;
+               totalram_pages -= VIRTIO_BALLOON_PAGES;
                vb->num_pages++;
                list_add(&page->lru,&vb->pages);
        }
@@ -131,8 +131,8 @@ static void release_pages_by_pfn(const u32 pfns[], unsigned 
int num)
        unsigned int i;

        for (i = 0; i<  num; i++) {
-               __free_page(pfn_to_page(pfns[i]));
-               totalram_pages++;
+               __free_pages(pfn_to_page(pfns[i]), VIRTIO_BALLOON_PAGE_ORDER);
+               totalram_pages += VIRTIO_BALLOON_PAGES;
        }
  }

@@ -146,7 +146,7 @@ static void leak_balloon(struct virtio_balloon *vb, size_t 
num)
        for (vb->num_pfns = 0; vb->num_pfns<  num; vb->num_pfns++) {
                page = list_first_entry(&vb->pages, struct page, lru);
                list_del(&page->lru);
-               vb->pfns[vb->num_pfns] = page_to_balloon_pfn(page);
+               vb->pfns[vb->num_pfns] = page_to_pfn(page);
                vb->num_pages--;
        }

@@ -400,7 +400,7 @@ static int virtballoon_restore(struct virtio_device *vdev)
        /* We don't have these pages in the balloon anymore! */
        list_for_each_entry_safe(page, page2,&vb->pages, lru) {
                list_del(&page->lru);
-               totalram_pages++;
+               totalram_pages += VIRTIO_BALLOON_PAGES;
        }
        return init_vqs(vdev->priv);
  }
diff --git a/include/linux/virtio_balloon.h b/include/linux/virtio_balloon.h
index 652dc8b..86840fe 100644
--- a/include/linux/virtio_balloon.h
+++ b/include/linux/virtio_balloon.h
@@ -33,7 +33,9 @@
  #define VIRTIO_BALLOON_F_STATS_VQ     1 /* Memory Stats virtqueue */

  /* Size of a PFN in the balloon interface. */
-#define VIRTIO_BALLOON_PFN_SHIFT 12
+#define VIRTIO_BALLOON_PFN_SHIFT  20
+#define VIRTIO_BALLOON_PAGE_ORDER (VIRTIO_BALLOON_PFN_SHIFT - PAGE_SHIFT)
+#define VIRTIO_BALLOON_PAGES      (1U<<  VIRTIO_BALLOON_PAGE_ORDER)

  struct virtio_balloon_config
  {

--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to