| Message ID | 1436243785-24105-4-git-send-email-gioh.kim@lge.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Jul 07, 2015 at 01:36:23PM +0900, Gioh Kim wrote: > From: Gioh Kim <gurugio@hanmail.net> > > Apply mobile page migration into balloon driver. > The balloong driver has an anonymous inode that manages > address_space_operation for page migration. > > Signed-off-by: Gioh Kim <gioh.kim@lge.com> > --- > drivers/virtio/virtio_balloon.c | 3 ++ > include/linux/balloon_compaction.h | 15 +++++++-- > mm/balloon_compaction.c | 65 +++++++++++++------------------------- > mm/compaction.c | 2 +- > mm/migrate.c | 2 +- > 5 files changed, 39 insertions(+), 48 deletions(-) > > diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c > index 82e80e0..ef5b9b5 100644 > --- a/drivers/virtio/virtio_balloon.c > +++ b/drivers/virtio/virtio_balloon.c > @@ -30,6 +30,7 @@ > #include <linux/balloon_compaction.h> > #include <linux/oom.h> > #include <linux/wait.h> > +#include <linux/anon_inodes.h> > > /* > * Balloon device works in 4K page units. So each page is pointed to by > @@ -505,6 +506,8 @@ static int virtballoon_probe(struct virtio_device *vdev) > balloon_devinfo_init(&vb->vb_dev_info); > #ifdef CONFIG_BALLOON_COMPACTION > vb->vb_dev_info.migratepage = virtballoon_migratepage; > + vb->vb_dev_info.inode = anon_inode_new(); > + vb->vb_dev_info.inode->i_mapping->a_ops = &balloon_aops; > #endif > > err = init_vqs(vb); > diff --git a/include/linux/balloon_compaction.h b/include/linux/balloon_compaction.h > index 9b0a15d..a9e0bde 100644 > --- a/include/linux/balloon_compaction.h > +++ b/include/linux/balloon_compaction.h > @@ -48,6 +48,7 @@ > #include <linux/migrate.h> > #include <linux/gfp.h> > #include <linux/err.h> > +#include <linux/fs.h> > > /* > * Balloon device information descriptor. > @@ -62,6 +63,7 @@ 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); > + struct inode *inode; > }; > > extern struct page *balloon_page_enqueue(struct balloon_dev_info *b_dev_info); > @@ -73,12 +75,16 @@ 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->inode = NULL; > } > > #ifdef CONFIG_BALLOON_COMPACTION > -extern bool balloon_page_isolate(struct page *page); > +extern const struct address_space_operations balloon_aops; > +extern bool balloon_page_isolate(struct page *page, > + isolate_mode_t mode); > extern void balloon_page_putback(struct page *page); > -extern int balloon_page_migrate(struct page *newpage, > +extern int balloon_page_migrate(struct address_space *mapping, > + struct page *newpage, > struct page *page, enum migrate_mode mode); > > /* > @@ -124,6 +130,7 @@ static inline void balloon_page_insert(struct balloon_dev_info *balloon, > struct page *page) > { > __SetPageBalloon(page); > + page->mapping = balloon->inode->i_mapping; > SetPagePrivate(page); > set_page_private(page, (unsigned long)balloon); > list_add(&page->lru, &balloon->pages); > @@ -140,6 +147,7 @@ static inline void balloon_page_insert(struct balloon_dev_info *balloon, > static inline void balloon_page_delete(struct page *page) > { > __ClearPageBalloon(page); > + page->mapping = NULL; > set_page_private(page, 0); > if (PagePrivate(page)) { > ClearPagePrivate(page); Order of cleanup here is not the reverse of the order of initialization. Better make it exactly the reverse. Also, I have a question: is it enough to lock the page to make changing the mapping safe? Do all users lock the page too? > @@ -191,7 +199,8 @@ static inline bool isolated_balloon_page(struct page *page) > return false; > } > > -static inline bool balloon_page_isolate(struct page *page) > +static inline bool balloon_page_isolate(struct page *page, > + isolate_mode_t mode) > { > return false; > } > diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c > index fcad832..0dd0b0d 100644 > --- a/mm/balloon_compaction.c > +++ b/mm/balloon_compaction.c > @@ -131,43 +131,16 @@ static inline void __putback_balloon_page(struct page *page) > } > > /* __isolate_lru_page() counterpart for a ballooned page */ > -bool balloon_page_isolate(struct page *page) > +bool balloon_page_isolate(struct page *page, isolate_mode_t mode) > { > /* > - * Avoid burning cycles with pages that are yet under __free_pages(), > - * or just got freed under us. > - * > - * In case we 'win' a race for a balloon page being freed under us and > - * raise its refcount preventing __free_pages() from doing its job > - * the put_page() at the end of this block will take care of > - * release this page, thus avoiding a nasty leakage. > + * A ballooned page, by default, has PagePrivate set. > + * Prevent concurrent compaction threads from isolating > + * an already isolated balloon page by clearing it. > */ > - if (likely(get_page_unless_zero(page))) { > - /* > - * As balloon pages are not isolated from LRU lists, concurrent > - * compaction threads can race against page migration functions > - * as well as race against the balloon driver releasing a page. > - * > - * In order to avoid having an already isolated balloon page > - * being (wrongly) re-isolated while it is under migration, > - * or to avoid attempting to isolate pages being released by > - * the balloon driver, lets be sure we have the page lock > - * before proceeding with the balloon page isolation steps. > - */ > - if (likely(trylock_page(page))) { > - /* > - * A ballooned page, by default, has PagePrivate set. > - * Prevent concurrent compaction threads from isolating > - * an already isolated balloon page by clearing it. > - */ > - if (balloon_page_movable(page)) { > - __isolate_balloon_page(page); > - unlock_page(page); > - return true; > - } > - unlock_page(page); > - } > - put_page(page); > + if (balloon_page_movable(page)) { > + __isolate_balloon_page(page); > + return true; > } > return false; > } > @@ -175,30 +148,28 @@ bool balloon_page_isolate(struct page *page) > /* putback_lru_page() counterpart for a ballooned page */ > void balloon_page_putback(struct page *page) > { > - /* > - * 'lock_page()' stabilizes the page and prevents races against > - * concurrent isolation threads attempting to re-isolate it. > - */ > - lock_page(page); > + if (!isolated_balloon_page(page)) > + return; > > if (__is_movable_balloon_page(page)) { > __putback_balloon_page(page); > - /* drop the extra ref count taken for page isolation */ > - put_page(page); > } else { > WARN_ON(1); > dump_page(page, "not movable balloon page"); > } > - unlock_page(page); > } > > /* move_to_new_page() counterpart for a ballooned page */ > -int balloon_page_migrate(struct page *newpage, > +int balloon_page_migrate(struct address_space *mapping, > + struct page *newpage, > struct page *page, enum migrate_mode mode) > { > struct balloon_dev_info *balloon = balloon_page_device(page); > int rc = -EAGAIN; > > + if (!isolated_balloon_page(page)) > + return rc; > + > /* > * Block others from accessing the 'newpage' when we get around to > * establishing additional references. We should be the only one > @@ -218,4 +189,12 @@ int balloon_page_migrate(struct page *newpage, > unlock_page(newpage); > return rc; > } > + > +/* define the balloon_mapping->a_ops callback to allow balloon page migration */ > +const struct address_space_operations balloon_aops = { > + .migratepage = balloon_page_migrate, > + .isolatepage = balloon_page_isolate, > + .putbackpage = balloon_page_putback, > +}; > +EXPORT_SYMBOL_GPL(balloon_aops); > #endif /* CONFIG_BALLOON_COMPACTION */ > diff --git a/mm/compaction.c b/mm/compaction.c > index 018f08d..81bafaf 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -719,7 +719,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, > */ > if (!PageLRU(page)) { > if (unlikely(balloon_page_movable(page))) { > - if (balloon_page_isolate(page)) { > + if (balloon_page_isolate(page, isolate_mode)) { > /* Successfully isolated */ > goto isolate_success; > } > diff --git a/mm/migrate.c b/mm/migrate.c > index f53838f..c94038e 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -852,7 +852,7 @@ static int __unmap_and_move(struct page *page, struct page *newpage, > * in order to avoid burning cycles at rmap level, and perform > * the page migration right away (proteced by page lock). > */ > - rc = balloon_page_migrate(newpage, page, mode); > + rc = balloon_page_migrate(page->mapping, newpage, page, mode); > goto out_unlock; > } > > -- > 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
>> @@ -124,6 +130,7 @@ static inline void balloon_page_insert(struct balloon_dev_info *balloon, >> struct page *page) >> { >> __SetPageBalloon(page); >> + page->mapping = balloon->inode->i_mapping; >> SetPagePrivate(page); >> set_page_private(page, (unsigned long)balloon); >> list_add(&page->lru, &balloon->pages); >> @@ -140,6 +147,7 @@ static inline void balloon_page_insert(struct balloon_dev_info *balloon, >> static inline void balloon_page_delete(struct page *page) >> { >> __ClearPageBalloon(page); >> + page->mapping = NULL; >> set_page_private(page, 0); >> if (PagePrivate(page)) { >> ClearPagePrivate(page); > > Order of cleanup here is not the reverse of the order of initialization. > Better make it exactly the reverse. > > > Also, I have a question: is it enough to lock the page to make changing > the mapping safe? Do all users lock the page too? > > > > I think balloon developers can answer that precisely. I've just follow this comment: http://lxr.free-electrons.com/source/include/linux/balloon_compaction.h#L16 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Jul 7, 2015 at 7:36 AM, Gioh Kim <gioh.kim@lge.com> wrote: > From: Gioh Kim <gurugio@hanmail.net> > > Apply mobile page migration into balloon driver. > The balloong driver has an anonymous inode that manages > address_space_operation for page migration. > > Signed-off-by: Gioh Kim <gioh.kim@lge.com> > --- > drivers/virtio/virtio_balloon.c | 3 ++ > include/linux/balloon_compaction.h | 15 +++++++-- > mm/balloon_compaction.c | 65 +++++++++++++------------------------- > mm/compaction.c | 2 +- > mm/migrate.c | 2 +- > 5 files changed, 39 insertions(+), 48 deletions(-) > > diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c > index 82e80e0..ef5b9b5 100644 > --- a/drivers/virtio/virtio_balloon.c > +++ b/drivers/virtio/virtio_balloon.c > @@ -30,6 +30,7 @@ > #include <linux/balloon_compaction.h> > #include <linux/oom.h> > #include <linux/wait.h> > +#include <linux/anon_inodes.h> > > /* > * Balloon device works in 4K page units. So each page is pointed to by > @@ -505,6 +506,8 @@ static int virtballoon_probe(struct virtio_device *vdev) > balloon_devinfo_init(&vb->vb_dev_info); > #ifdef CONFIG_BALLOON_COMPACTION > vb->vb_dev_info.migratepage = virtballoon_migratepage; > + vb->vb_dev_info.inode = anon_inode_new(); > + vb->vb_dev_info.inode->i_mapping->a_ops = &balloon_aops; > #endif > > err = init_vqs(vb); > diff --git a/include/linux/balloon_compaction.h b/include/linux/balloon_compaction.h > index 9b0a15d..a9e0bde 100644 > --- a/include/linux/balloon_compaction.h > +++ b/include/linux/balloon_compaction.h > @@ -48,6 +48,7 @@ > #include <linux/migrate.h> > #include <linux/gfp.h> > #include <linux/err.h> > +#include <linux/fs.h> > > /* > * Balloon device information descriptor. > @@ -62,6 +63,7 @@ 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); > + struct inode *inode; > }; > > extern struct page *balloon_page_enqueue(struct balloon_dev_info *b_dev_info); > @@ -73,12 +75,16 @@ 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->inode = NULL; > } > > #ifdef CONFIG_BALLOON_COMPACTION > -extern bool balloon_page_isolate(struct page *page); > +extern const struct address_space_operations balloon_aops; > +extern bool balloon_page_isolate(struct page *page, > + isolate_mode_t mode); > extern void balloon_page_putback(struct page *page); > -extern int balloon_page_migrate(struct page *newpage, > +extern int balloon_page_migrate(struct address_space *mapping, > + struct page *newpage, > struct page *page, enum migrate_mode mode); > > /* > @@ -124,6 +130,7 @@ static inline void balloon_page_insert(struct balloon_dev_info *balloon, > struct page *page) > { > __SetPageBalloon(page); > + page->mapping = balloon->inode->i_mapping; > SetPagePrivate(page); > set_page_private(page, (unsigned long)balloon); > list_add(&page->lru, &balloon->pages); > @@ -140,6 +147,7 @@ static inline void balloon_page_insert(struct balloon_dev_info *balloon, > static inline void balloon_page_delete(struct page *page) > { > __ClearPageBalloon(page); > + page->mapping = NULL; > set_page_private(page, 0); > if (PagePrivate(page)) { > ClearPagePrivate(page); > @@ -191,7 +199,8 @@ static inline bool isolated_balloon_page(struct page *page) > return false; > } > > -static inline bool balloon_page_isolate(struct page *page) > +static inline bool balloon_page_isolate(struct page *page, > + isolate_mode_t mode) > { > return false; > } > diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c > index fcad832..0dd0b0d 100644 > --- a/mm/balloon_compaction.c > +++ b/mm/balloon_compaction.c > @@ -131,43 +131,16 @@ static inline void __putback_balloon_page(struct page *page) > } > > /* __isolate_lru_page() counterpart for a ballooned page */ > -bool balloon_page_isolate(struct page *page) > +bool balloon_page_isolate(struct page *page, isolate_mode_t mode) > { > /* > - * Avoid burning cycles with pages that are yet under __free_pages(), > - * or just got freed under us. > - * > - * In case we 'win' a race for a balloon page being freed under us and > - * raise its refcount preventing __free_pages() from doing its job > - * the put_page() at the end of this block will take care of > - * release this page, thus avoiding a nasty leakage. > + * A ballooned page, by default, has PagePrivate set. > + * Prevent concurrent compaction threads from isolating > + * an already isolated balloon page by clearing it. > */ > - if (likely(get_page_unless_zero(page))) { > - /* > - * As balloon pages are not isolated from LRU lists, concurrent > - * compaction threads can race against page migration functions > - * as well as race against the balloon driver releasing a page. > - * > - * In order to avoid having an already isolated balloon page > - * being (wrongly) re-isolated while it is under migration, > - * or to avoid attempting to isolate pages being released by > - * the balloon driver, lets be sure we have the page lock > - * before proceeding with the balloon page isolation steps. > - */ > - if (likely(trylock_page(page))) { > - /* > - * A ballooned page, by default, has PagePrivate set. > - * Prevent concurrent compaction threads from isolating > - * an already isolated balloon page by clearing it. > - */ > - if (balloon_page_movable(page)) { > - __isolate_balloon_page(page); > - unlock_page(page); > - return true; > - } > - unlock_page(page); > - } > - put_page(page); > + if (balloon_page_movable(page)) { > + __isolate_balloon_page(page); > + return true; > } > return false; > } > @@ -175,30 +148,28 @@ bool balloon_page_isolate(struct page *page) > /* putback_lru_page() counterpart for a ballooned page */ > void balloon_page_putback(struct page *page) > { > - /* > - * 'lock_page()' stabilizes the page and prevents races against > - * concurrent isolation threads attempting to re-isolate it. > - */ > - lock_page(page); > + if (!isolated_balloon_page(page)) > + return; > > if (__is_movable_balloon_page(page)) { > __putback_balloon_page(page); > - /* drop the extra ref count taken for page isolation */ > - put_page(page); > } else { > WARN_ON(1); > dump_page(page, "not movable balloon page"); > } > - unlock_page(page); > } > > /* move_to_new_page() counterpart for a ballooned page */ > -int balloon_page_migrate(struct page *newpage, > +int balloon_page_migrate(struct address_space *mapping, > + struct page *newpage, > struct page *page, enum migrate_mode mode) > { > struct balloon_dev_info *balloon = balloon_page_device(page); > int rc = -EAGAIN; > > + if (!isolated_balloon_page(page)) > + return rc; > + > /* > * Block others from accessing the 'newpage' when we get around to > * establishing additional references. We should be the only one > @@ -218,4 +189,12 @@ int balloon_page_migrate(struct page *newpage, > unlock_page(newpage); Both pages passed as arguments of ->migratepage() are locked. So, please remove lock/unlock from this function here and add lock/unlock newpage in __unmap_and_move() below. Right in this patch. > return rc; > } > + > +/* define the balloon_mapping->a_ops callback to allow balloon page migration */ > +const struct address_space_operations balloon_aops = { > + .migratepage = balloon_page_migrate, > + .isolatepage = balloon_page_isolate, > + .putbackpage = balloon_page_putback, > +}; > +EXPORT_SYMBOL_GPL(balloon_aops); > #endif /* CONFIG_BALLOON_COMPACTION */ > diff --git a/mm/compaction.c b/mm/compaction.c > index 018f08d..81bafaf 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -719,7 +719,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, > */ > if (!PageLRU(page)) { > if (unlikely(balloon_page_movable(page))) { > - if (balloon_page_isolate(page)) { > + if (balloon_page_isolate(page, isolate_mode)) { > /* Successfully isolated */ > goto isolate_success; > } > diff --git a/mm/migrate.c b/mm/migrate.c > index f53838f..c94038e 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -852,7 +852,7 @@ static int __unmap_and_move(struct page *page, struct page *newpage, > * in order to avoid burning cycles at rmap level, and perform > * the page migration right away (proteced by page lock). > */ > - rc = balloon_page_migrate(newpage, page, mode); Here: lock_page(newpage); > + rc = balloon_page_migrate(page->mapping, newpage, page, mode); unlock_page(newpage); > goto out_unlock; > } > > -- > 2.1.4 > -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 82e80e0..ef5b9b5 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -30,6 +30,7 @@ #include <linux/balloon_compaction.h> #include <linux/oom.h> #include <linux/wait.h> +#include <linux/anon_inodes.h> /* * Balloon device works in 4K page units. So each page is pointed to by @@ -505,6 +506,8 @@ static int virtballoon_probe(struct virtio_device *vdev) balloon_devinfo_init(&vb->vb_dev_info); #ifdef CONFIG_BALLOON_COMPACTION vb->vb_dev_info.migratepage = virtballoon_migratepage; + vb->vb_dev_info.inode = anon_inode_new(); + vb->vb_dev_info.inode->i_mapping->a_ops = &balloon_aops; #endif err = init_vqs(vb); diff --git a/include/linux/balloon_compaction.h b/include/linux/balloon_compaction.h index 9b0a15d..a9e0bde 100644 --- a/include/linux/balloon_compaction.h +++ b/include/linux/balloon_compaction.h @@ -48,6 +48,7 @@ #include <linux/migrate.h> #include <linux/gfp.h> #include <linux/err.h> +#include <linux/fs.h> /* * Balloon device information descriptor. @@ -62,6 +63,7 @@ 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); + struct inode *inode; }; extern struct page *balloon_page_enqueue(struct balloon_dev_info *b_dev_info); @@ -73,12 +75,16 @@ 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->inode = NULL; } #ifdef CONFIG_BALLOON_COMPACTION -extern bool balloon_page_isolate(struct page *page); +extern const struct address_space_operations balloon_aops; +extern bool balloon_page_isolate(struct page *page, + isolate_mode_t mode); extern void balloon_page_putback(struct page *page); -extern int balloon_page_migrate(struct page *newpage, +extern int balloon_page_migrate(struct address_space *mapping, + struct page *newpage, struct page *page, enum migrate_mode mode); /* @@ -124,6 +130,7 @@ static inline void balloon_page_insert(struct balloon_dev_info *balloon, struct page *page) { __SetPageBalloon(page); + page->mapping = balloon->inode->i_mapping; SetPagePrivate(page); set_page_private(page, (unsigned long)balloon); list_add(&page->lru, &balloon->pages); @@ -140,6 +147,7 @@ static inline void balloon_page_insert(struct balloon_dev_info *balloon, static inline void balloon_page_delete(struct page *page) { __ClearPageBalloon(page); + page->mapping = NULL; set_page_private(page, 0); if (PagePrivate(page)) { ClearPagePrivate(page); @@ -191,7 +199,8 @@ static inline bool isolated_balloon_page(struct page *page) return false; } -static inline bool balloon_page_isolate(struct page *page) +static inline bool balloon_page_isolate(struct page *page, + isolate_mode_t mode) { return false; } diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c index fcad832..0dd0b0d 100644 --- a/mm/balloon_compaction.c +++ b/mm/balloon_compaction.c @@ -131,43 +131,16 @@ static inline void __putback_balloon_page(struct page *page) } /* __isolate_lru_page() counterpart for a ballooned page */ -bool balloon_page_isolate(struct page *page) +bool balloon_page_isolate(struct page *page, isolate_mode_t mode) { /* - * Avoid burning cycles with pages that are yet under __free_pages(), - * or just got freed under us. - * - * In case we 'win' a race for a balloon page being freed under us and - * raise its refcount preventing __free_pages() from doing its job - * the put_page() at the end of this block will take care of - * release this page, thus avoiding a nasty leakage. + * A ballooned page, by default, has PagePrivate set. + * Prevent concurrent compaction threads from isolating + * an already isolated balloon page by clearing it. */ - if (likely(get_page_unless_zero(page))) { - /* - * As balloon pages are not isolated from LRU lists, concurrent - * compaction threads can race against page migration functions - * as well as race against the balloon driver releasing a page. - * - * In order to avoid having an already isolated balloon page - * being (wrongly) re-isolated while it is under migration, - * or to avoid attempting to isolate pages being released by - * the balloon driver, lets be sure we have the page lock - * before proceeding with the balloon page isolation steps. - */ - if (likely(trylock_page(page))) { - /* - * A ballooned page, by default, has PagePrivate set. - * Prevent concurrent compaction threads from isolating - * an already isolated balloon page by clearing it. - */ - if (balloon_page_movable(page)) { - __isolate_balloon_page(page); - unlock_page(page); - return true; - } - unlock_page(page); - } - put_page(page); + if (balloon_page_movable(page)) { + __isolate_balloon_page(page); + return true; } return false; } @@ -175,30 +148,28 @@ bool balloon_page_isolate(struct page *page) /* putback_lru_page() counterpart for a ballooned page */ void balloon_page_putback(struct page *page) { - /* - * 'lock_page()' stabilizes the page and prevents races against - * concurrent isolation threads attempting to re-isolate it. - */ - lock_page(page); + if (!isolated_balloon_page(page)) + return; if (__is_movable_balloon_page(page)) { __putback_balloon_page(page); - /* drop the extra ref count taken for page isolation */ - put_page(page); } else { WARN_ON(1); dump_page(page, "not movable balloon page"); } - unlock_page(page); } /* move_to_new_page() counterpart for a ballooned page */ -int balloon_page_migrate(struct page *newpage, +int balloon_page_migrate(struct address_space *mapping, + struct page *newpage, struct page *page, enum migrate_mode mode) { struct balloon_dev_info *balloon = balloon_page_device(page); int rc = -EAGAIN; + if (!isolated_balloon_page(page)) + return rc; + /* * Block others from accessing the 'newpage' when we get around to * establishing additional references. We should be the only one @@ -218,4 +189,12 @@ int balloon_page_migrate(struct page *newpage, unlock_page(newpage); return rc; } + +/* define the balloon_mapping->a_ops callback to allow balloon page migration */ +const struct address_space_operations balloon_aops = { + .migratepage = balloon_page_migrate, + .isolatepage = balloon_page_isolate, + .putbackpage = balloon_page_putback, +}; +EXPORT_SYMBOL_GPL(balloon_aops); #endif /* CONFIG_BALLOON_COMPACTION */ diff --git a/mm/compaction.c b/mm/compaction.c index 018f08d..81bafaf 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -719,7 +719,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, */ if (!PageLRU(page)) { if (unlikely(balloon_page_movable(page))) { - if (balloon_page_isolate(page)) { + if (balloon_page_isolate(page, isolate_mode)) { /* Successfully isolated */ goto isolate_success; } diff --git a/mm/migrate.c b/mm/migrate.c index f53838f..c94038e 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -852,7 +852,7 @@ static int __unmap_and_move(struct page *page, struct page *newpage, * in order to avoid burning cycles at rmap level, and perform * the page migration right away (proteced by page lock). */ - rc = balloon_page_migrate(newpage, page, mode); + rc = balloon_page_migrate(page->mapping, newpage, page, mode); goto out_unlock; }