From: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx>
After commit f2452d14cdb3 ("mm/sl*b: Differentiate struct slab fields by
sl*b implementations"), we can reorder fields of struct slab depending
on slab allocator.
For now, page_mapcount_reset() is called because page->_mapcount and
slab->units have same offset. But this is not necessary for struct slab.
Use unused field for units instead.
Signed-off-by: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx>
Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
Link: https://lore.kernel.org/r/20211212065241.GA886691@odroid
---
mm/slab.h | 4 ++--
mm/slob.c | 1 -
2 files changed, 2 insertions(+), 3 deletions(-)
diff --git a/mm/slab.h b/mm/slab.h
index ac8be7dab535..e10d0d4c9bfa 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -50,8 +50,8 @@ struct slab {
struct list_head slab_list;
void *__unused_1;
void *freelist; /* first free block */
- void *__unused_2;
- int units;
+ long units;
+ unsigned int __unused_2;
#else
#error "Unexpected slab allocator configured"
diff --git a/mm/slob.c b/mm/slob.c
index 3c6cadbbc238..60c5842215f1 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -404,7 +404,6 @@ static void slob_free(void *block, int size)
clear_slob_page_free(sp);
spin_unlock_irqrestore(&slob_lock, flags);
__folio_clear_slab(slab_folio(sp));
- page_mapcount_reset(slab_page(sp));
slob_free_pages(b, 0);
return;
}
--
2.34.1
