mm/balloon_compaction: remove balloon mapping and flag AS_BALLOON_MAP

Now ballooned pages are detected using PageBalloon().  Fake mapping is no
longer required.  This patch links ballooned pages to balloon device using
field page->private instead of page->mapping.  Also this patch embeds
balloon_dev_info directly into struct virtio_balloon.

Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Konstantin Khlebnikov
2014-10-09 15:29:29 -07:00
committed by Linus Torvalds
parent d6d86c0a7f
commit 9d1ba80564
4 changed files with 39 additions and 206 deletions

View File

@@ -59,7 +59,7 @@ struct virtio_balloon
* Each page on this list adds VIRTIO_BALLOON_PAGES_PER_PAGE
* to num_pages above.
*/
struct balloon_dev_info *vb_dev_info;
struct balloon_dev_info vb_dev_info;
/* Synchronize access/update to this struct virtio_balloon elements */
struct mutex balloon_lock;
@@ -127,7 +127,7 @@ static void set_page_pfns(u32 pfns[], struct page *page)
static void fill_balloon(struct virtio_balloon *vb, size_t num)
{
struct balloon_dev_info *vb_dev_info = vb->vb_dev_info;
struct balloon_dev_info *vb_dev_info = &vb->vb_dev_info;
/* We can only do one array worth at a time. */
num = min(num, ARRAY_SIZE(vb->pfns));
@@ -171,7 +171,7 @@ static void release_pages_by_pfn(const u32 pfns[], unsigned int num)
static void leak_balloon(struct virtio_balloon *vb, size_t num)
{
struct page *page;
struct balloon_dev_info *vb_dev_info = vb->vb_dev_info;
struct balloon_dev_info *vb_dev_info = &vb->vb_dev_info;
/* We can only do one array worth at a time. */
num = min(num, ARRAY_SIZE(vb->pfns));
@@ -353,12 +353,11 @@ static int init_vqs(struct virtio_balloon *vb)
return 0;
}
static const struct address_space_operations virtio_balloon_aops;
#ifdef CONFIG_BALLOON_COMPACTION
/*
* virtballoon_migratepage - perform the balloon page migration on behalf of
* a compation thread. (called under page lock)
* @mapping: the page->mapping which will be assigned to the new migrated page.
* @vb_dev_info: the balloon device
* @newpage: page that will replace the isolated page after migration finishes.
* @page : the isolated (old) page that is about to be migrated to newpage.
* @mode : compaction mode -- not used for balloon page migration.
@@ -373,17 +372,13 @@ static const struct address_space_operations virtio_balloon_aops;
* This function preforms the balloon page migration task.
* Called through balloon_mapping->a_ops->migratepage
*/
static int virtballoon_migratepage(struct address_space *mapping,
static int virtballoon_migratepage(struct balloon_dev_info *vb_dev_info,
struct page *newpage, struct page *page, enum migrate_mode mode)
{
struct balloon_dev_info *vb_dev_info = balloon_page_device(page);
struct virtio_balloon *vb;
struct virtio_balloon *vb = container_of(vb_dev_info,
struct virtio_balloon, vb_dev_info);
unsigned long flags;
BUG_ON(!vb_dev_info);
vb = vb_dev_info->balloon_device;
/*
* In order to avoid lock contention while migrating pages concurrently
* to leak_balloon() or fill_balloon() we just give up the balloon_lock
@@ -399,7 +394,7 @@ static int virtballoon_migratepage(struct address_space *mapping,
/* balloon's page migration 1st step -- inflate "newpage" */
spin_lock_irqsave(&vb_dev_info->pages_lock, flags);
balloon_page_insert(newpage, mapping, &vb_dev_info->pages);
balloon_page_insert(vb_dev_info, newpage);
vb_dev_info->isolated_pages--;
spin_unlock_irqrestore(&vb_dev_info->pages_lock, flags);
vb->num_pfns = VIRTIO_BALLOON_PAGES_PER_PAGE;
@@ -418,18 +413,11 @@ static int virtballoon_migratepage(struct address_space *mapping,
return MIGRATEPAGE_SUCCESS;
}
/* define the balloon_mapping->a_ops callback to allow balloon page migration */
static const struct address_space_operations virtio_balloon_aops = {
.migratepage = virtballoon_migratepage,
};
#endif /* CONFIG_BALLOON_COMPACTION */
static int virtballoon_probe(struct virtio_device *vdev)
{
struct virtio_balloon *vb;
struct address_space *vb_mapping;
struct balloon_dev_info *vb_devinfo;
int err;
vdev->priv = vb = kmalloc(sizeof(*vb), GFP_KERNEL);
@@ -445,30 +433,14 @@ static int virtballoon_probe(struct virtio_device *vdev)
vb->vdev = vdev;
vb->need_stats_update = 0;
vb_devinfo = balloon_devinfo_alloc(vb);
if (IS_ERR(vb_devinfo)) {
err = PTR_ERR(vb_devinfo);
goto out_free_vb;
}
vb_mapping = balloon_mapping_alloc(vb_devinfo,
(balloon_compaction_check()) ?
&virtio_balloon_aops : NULL);
if (IS_ERR(vb_mapping)) {
/*
* IS_ERR(vb_mapping) && PTR_ERR(vb_mapping) == -EOPNOTSUPP
* This means !CONFIG_BALLOON_COMPACTION, otherwise we get off.
*/
err = PTR_ERR(vb_mapping);
if (err != -EOPNOTSUPP)
goto out_free_vb_devinfo;
}
vb->vb_dev_info = vb_devinfo;
balloon_devinfo_init(&vb->vb_dev_info);
#ifdef CONFIG_BALLOON_COMPACTION
vb->vb_dev_info.migratepage = virtballoon_migratepage;
#endif
err = init_vqs(vb);
if (err)
goto out_free_vb_mapping;
goto out_free_vb;
vb->thread = kthread_run(balloon, vb, "vballoon");
if (IS_ERR(vb->thread)) {
@@ -480,10 +452,6 @@ static int virtballoon_probe(struct virtio_device *vdev)
out_del_vqs:
vdev->config->del_vqs(vdev);
out_free_vb_mapping:
balloon_mapping_free(vb_mapping);
out_free_vb_devinfo:
balloon_devinfo_free(vb_devinfo);
out_free_vb:
kfree(vb);
out:
@@ -509,8 +477,6 @@ static void virtballoon_remove(struct virtio_device *vdev)
kthread_stop(vb->thread);
remove_common(vb);
balloon_mapping_free(vb->vb_dev_info->mapping);
balloon_devinfo_free(vb->vb_dev_info);
kfree(vb);
}