On 02/20/2012 11:34 AM, Prasad Joshi wrote:
Signed-off-by: Prasad Joshi<prasadjoshi.linux@xxxxxxxxx>
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
{
--
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