* David Hildenbrand (Red Hat) <[email protected]> [260115 04:21]: > Let's centralize it, by allowing for the driver to enable this handling > through a new flag (bool for now) in the balloon device info. > > Note that we now adjust the counter when adding/removing a page into the > balloon list: when removing a page to deflate it, it will now happen > before the driver communicated with hypervisor, not afterwards. > > This shouldn't make a difference in practice. > > Signed-off-by: David Hildenbrand (Red Hat) <[email protected]>
For what it's worth, Acked-by: Liam R. Howlett <[email protected]> > --- > arch/powerpc/platforms/pseries/cmm.c | 13 +------------ > drivers/virtio/virtio_balloon.c | 19 ++----------------- > include/linux/balloon_compaction.h | 2 ++ > mm/balloon_compaction.c | 17 +++++++++++++++++ > 4 files changed, 22 insertions(+), 29 deletions(-) > > diff --git a/arch/powerpc/platforms/pseries/cmm.c > b/arch/powerpc/platforms/pseries/cmm.c > index 15f873f733a41..7fd8b3d7e7637 100644 > --- a/arch/powerpc/platforms/pseries/cmm.c > +++ b/arch/powerpc/platforms/pseries/cmm.c > @@ -165,7 +165,6 @@ static long cmm_alloc_pages(long nr) > > balloon_page_enqueue(&b_dev_info, page); > atomic_long_inc(&loaned_pages); > - adjust_managed_page_count(page, -1); > nr--; > } > > @@ -190,7 +189,6 @@ static long cmm_free_pages(long nr) > if (!page) > break; > plpar_page_set_active(page); > - adjust_managed_page_count(page, 1); > __free_page(page); > atomic_long_dec(&loaned_pages); > nr--; > @@ -515,16 +513,6 @@ static int cmm_migratepage(struct balloon_dev_info > *b_dev_info, > return -EBUSY; > } > > - /* > - * When we migrate a page to a different zone, we have to fixup the > - * count of both involved zones as we adjusted the managed page count > - * when inflating. > - */ > - if (page_zone(page) != page_zone(newpage)) { > - adjust_managed_page_count(page, 1); > - adjust_managed_page_count(newpage, -1); > - } > - > /* > * activate/"deflate" the old page. We ignore any errors just like the > * other callers. > @@ -551,6 +539,7 @@ static int cmm_init(void) > return -EOPNOTSUPP; > > balloon_devinfo_init(&b_dev_info); > + b_dev_info.adjust_managed_page_count = true; > if (IS_ENABLED(CONFIG_BALLOON_COMPACTION)) > b_dev_info.migratepage = cmm_migratepage; > > diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c > index df2756c071dae..15c1cf5fd249c 100644 > --- a/drivers/virtio/virtio_balloon.c > +++ b/drivers/virtio/virtio_balloon.c > @@ -274,9 +274,6 @@ static unsigned int fill_balloon(struct virtio_balloon > *vb, size_t num) > > set_page_pfns(vb, vb->pfns + vb->num_pfns, page); > vb->num_pages += VIRTIO_BALLOON_PAGES_PER_PAGE; > - if (!virtio_has_feature(vb->vdev, > - VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) > - adjust_managed_page_count(page, -1); > vb->num_pfns += VIRTIO_BALLOON_PAGES_PER_PAGE; > } > > @@ -295,9 +292,6 @@ static void release_pages_balloon(struct virtio_balloon > *vb, > struct page *page, *next; > > list_for_each_entry_safe(page, next, pages, lru) { > - if (!virtio_has_feature(vb->vdev, > - VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) > - adjust_managed_page_count(page, 1); > list_del(&page->lru); > put_page(page); /* balloon reference */ > } > @@ -839,17 +833,6 @@ static int virtballoon_migratepage(struct > balloon_dev_info *vb_dev_info, > if (!mutex_trylock(&vb->balloon_lock)) > return -EAGAIN; > > - /* > - * When we migrate a page to a different zone and adjusted the > - * managed page count when inflating, we have to fixup the count of > - * both involved zones. > - */ > - if (!virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_DEFLATE_ON_OOM) && > - page_zone(page) != page_zone(newpage)) { > - adjust_managed_page_count(page, 1); > - adjust_managed_page_count(newpage, -1); > - } > - > /* balloon's page migration 1st step -- inflate "newpage" */ > vb->num_pfns = VIRTIO_BALLOON_PAGES_PER_PAGE; > set_page_pfns(vb, vb->pfns, newpage); > @@ -958,6 +941,8 @@ static int virtballoon_probe(struct virtio_device *vdev) > if (err) > goto out_free_vb; > > + if (!virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) > + vb->vb_dev_info.adjust_managed_page_count = true; > #ifdef CONFIG_BALLOON_COMPACTION > vb->vb_dev_info.migratepage = virtballoon_migratepage; > #endif > diff --git a/include/linux/balloon_compaction.h > b/include/linux/balloon_compaction.h > index 7cfe48769239e..3109d3c43d306 100644 > --- a/include/linux/balloon_compaction.h > +++ b/include/linux/balloon_compaction.h > @@ -56,6 +56,7 @@ struct balloon_dev_info { > struct list_head pages; /* Pages enqueued & handled to Host */ > int (*migratepage)(struct balloon_dev_info *, struct page *newpage, > struct page *page, enum migrate_mode mode); > + bool adjust_managed_page_count; > }; > > extern struct page *balloon_page_alloc(void); > @@ -73,6 +74,7 @@ static inline void balloon_devinfo_init(struct > balloon_dev_info *balloon) > spin_lock_init(&balloon->pages_lock); > INIT_LIST_HEAD(&balloon->pages); > balloon->migratepage = NULL; > + balloon->adjust_managed_page_count = false; > } > > #ifdef CONFIG_BALLOON_COMPACTION > diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c > index 5444c61bb9e76..fd9ec47cf4670 100644 > --- a/mm/balloon_compaction.c > +++ b/mm/balloon_compaction.c > @@ -23,6 +23,8 @@ static void balloon_page_enqueue_one(struct > balloon_dev_info *b_dev_info, > BUG_ON(!trylock_page(page)); > balloon_page_insert(b_dev_info, page); > unlock_page(page); > + if (b_dev_info->adjust_managed_page_count) > + adjust_managed_page_count(page, -1); > __count_vm_event(BALLOON_INFLATE); > inc_node_page_state(page, NR_BALLOON_PAGES); > } > @@ -95,6 +97,8 @@ size_t balloon_page_list_dequeue(struct balloon_dev_info > *b_dev_info, > continue; > > list_del(&page->lru); > + if (b_dev_info->adjust_managed_page_count) > + adjust_managed_page_count(page, 1); > balloon_page_finalize(page); > __count_vm_event(BALLOON_DEFLATE); > list_add(&page->lru, pages); > @@ -256,12 +260,25 @@ static int balloon_page_migrate(struct page *newpage, > struct page *page, > > balloon_page_insert(b_dev_info, newpage); > __count_vm_event(BALLOON_MIGRATE); > + > + if (b_dev_info->adjust_managed_page_count && > + page_zone(page) != page_zone(newpage)) { > + /* > + * When we migrate a page to a different zone we > + * have to fixup the count of both involved zones. > + */ > + adjust_managed_page_count(page, 1); > + adjust_managed_page_count(newpage, -1); > + } > break; > case -ENOENT: > spin_lock_irqsave(&b_dev_info->pages_lock, flags); > > /* Old page was deflated but new page not inflated. */ > __count_vm_event(BALLOON_DEFLATE); > + > + if (b_dev_info->adjust_managed_page_count) > + adjust_managed_page_count(page, 1); > break; > default: > return rc; > -- > 2.52.0 >
