[PATCH v5 09/12] zsmalloc: separate free_zspage from putback_zspage

Minchan Kim
2016-05-09T02:20:29Z

Currently, putback_zspage does free zspage under class->lock
if fullness become ZS_EMPTY but it makes trouble to implement
locking scheme for new zspage migration.
So, this patch is to separate free_zspage from putback_zspage
and free zspage out of class->lock which is preparation for
zspage migration.

Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
---
mm/zsmalloc.c | 27 +++++++++++----------------
1 file changed, 11 insertions(+), 16 deletions(-)

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 162a598a417a..5ccd83732a14 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -1685,14 +1685,12 @@ static struct zspage *isolate_zspage(struct size_class *class, bool source)

/*
* putback_zspage - add @zspage into right class's fullness list
- * @pool: target pool
* @class: destination class
* @zspage: target page
*
* Return @zspage's fullness_group
*/
-static enum fullness_group putback_zspage(struct zs_pool *pool,
- struct size_class *class,
+static enum fullness_group putback_zspage(struct size_class *class,
struct zspage *zspage)
{
enum fullness_group fullness;
@@ -1701,15 +1699,6 @@ static enum fullness_group putback_zspage(struct zs_pool *pool,
insert_zspage(class, zspage, fullness);
set_zspage_mapping(zspage, class->index, fullness);

- if (fullness == ZS_EMPTY) {
- zs_stat_dec(class, OBJ_ALLOCATED, get_maxobj_per_zspage(
- class->size, class->pages_per_zspage));
- atomic_long_sub(class->pages_per_zspage,
- &pool->pages_allocated);
-
- free_zspage(pool, zspage);
- }
-
return fullness;
}

@@ -1755,23 +1744,29 @@ static void __zs_compact(struct zs_pool *pool, struct size_class *class)
if (!migrate_zspage(pool, class, &cc))
break;

- putback_zspage(pool, class, dst_zspage);
+ putback_zspage(class, dst_zspage);
}

/* Stop if we couldn't find slot */
if (dst_zspage == NULL)
break;

- putback_zspage(pool, class, dst_zspage);
- if (putback_zspage(pool, class, src_zspage) == ZS_EMPTY)
+ putback_zspage(class, dst_zspage);
+ if (putback_zspage(class, src_zspage) == ZS_EMPTY) {
+ zs_stat_dec(class, OBJ_ALLOCATED, get_maxobj_per_zspage(
+ class->size, class->pages_per_zspage));
+ atomic_long_sub(class->pages_per_zspage,
+ &pool->pages_allocated);
+ free_zspage(pool, src_zspage);
pool->stats.pages_compacted += class->pages_per_zspage;
+ }
spin_unlock(&class->lock);
cond_resched();
spin_lock(&class->lock);
}

if (src_zspage)
- putback_zspage(pool, class, src_zspage);
+ putback_zspage(class, src_zspage);

spin_unlock(&class->lock);
}
--
1.9.1