On Tue, Aug 21, 2012 at 09:47:47AM -0300, Rafael Aquini wrote:
> The PATCH "mm: introduce compaction and migration for virtio ballooned pages"
> hacks around putback_lru_pages() in order to allow ballooned pages to be
> re-inserted on balloon page list as if a ballooned page was like a LRU page.
>
> As ballooned pages are not legitimate LRU pages, this patch introduces
> putback_movable_pages() to properly cope with cases where the isolated
> pageset contains ballooned pages and LRU pages, thus fixing the mentioned
> inelegant hack around putback_lru_pages().
>
> Signed-off-by: Rafael Aquini <aqu...@redhat.com>
> ---
> include/linux/migrate.h | 2 ++
> mm/compaction.c | 4 ++--
> mm/migrate.c | 20 ++++++++++++++++++++
> mm/page_alloc.c | 2 +-
> 4 files changed, 25 insertions(+), 3 deletions(-)
>
> diff --git a/include/linux/migrate.h b/include/linux/migrate.h
> index ce7e667..ff103a1 100644
> --- a/include/linux/migrate.h
> +++ b/include/linux/migrate.h
> @@ -10,6 +10,7 @@ typedef struct page *new_page_t(struct page *, unsigned
> long private, int **);
> #ifdef CONFIG_MIGRATION
>
> extern void putback_lru_pages(struct list_head *l);
> +extern void putback_movable_pages(struct list_head *l);
> extern int migrate_page(struct address_space *,
> struct page *, struct page *, enum migrate_mode);
> extern int migrate_pages(struct list_head *l, new_page_t x,
> @@ -33,6 +34,7 @@ extern int migrate_huge_page_move_mapping(struct
> address_space *mapping,
> #else
>
> static inline void putback_lru_pages(struct list_head *l) {}
> +static inline void putback_movable_pages(struct list_head *l) {}
> static inline int migrate_pages(struct list_head *l, new_page_t x,
> unsigned long private, bool offlining,
> enum migrate_mode mode) { return -ENOSYS; }
> diff --git a/mm/compaction.c b/mm/compaction.c
> index ce43dc2..782ed32 100644
> --- a/mm/compaction.c
> +++ b/mm/compaction.c
> @@ -759,9 +759,9 @@ static int compact_zone(struct zone *zone, struct
> compact_control *cc)
> trace_mm_compaction_migratepages(nr_migrate - nr_remaining,
> nr_remaining);
>
> - /* Release LRU pages not migrated */
> + /* Release isolated pages not migrated */
> if (err) {
> - putback_lru_pages(&cc->migratepages);
> + putback_movable_pages(&cc->migratepages);
> cc->nr_migratepages = 0;
> if (err == -ENOMEM) {
> ret = COMPACT_PARTIAL;
> diff --git a/mm/migrate.c b/mm/migrate.c
> index 6392da258..0bf2caf 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -80,6 +80,26 @@ void putback_lru_pages(struct list_head *l)
> list_del(&page->lru);
> dec_zone_page_state(page, NR_ISOLATED_ANON +
> page_is_file_cache(page));
> + putback_lru_page(page);
> + }
> +}
> +
> +/*
> + * Put previously isolated pages back onto the appropriated lists
Do you mean appropriate lists?
> + * from where they were once taken off for compaction/migration.
> + *
> + * This function shall be used instead of putback_lru_pages(),
> + * whenever the isolated pageset has been built by
> isolate_migratepages_range()
> + */
> +void putback_movable_pages(struct list_head *l)
> +{
> + struct page *page;
> + struct page *page2;
> +
> + list_for_each_entry_safe(page, page2, l, lru) {
> + list_del(&page->lru);
> + dec_zone_page_state(page, NR_ISOLATED_ANON +
> + page_is_file_cache(page));
> if (unlikely(movable_balloon_page(page)))
> putback_balloon_page(page);
> else
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 009ac28..78b7663 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -5669,7 +5669,7 @@ static int __alloc_contig_migrate_range(unsigned long
> start, unsigned long end)
> 0, false, MIGRATE_SYNC);
> }
>
> - putback_lru_pages(&cc.migratepages);
> + putback_movable_pages(&cc.migratepages);
> return ret > 0 ? 0 : ret;
> }
>
> --
> 1.7.11.4
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