[PATCH 08/11] PageSlab: eliminate unnecessary compound_head() calls in mm/slab_common

From: Johannes Weiner
Date: Tue Oct 12 2021 - 14:02:38 EST


virt_to_head_page() implies it.

Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
---
mm/slab.h | 3 +--
mm/slab_common.c | 4 ++--
2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/mm/slab.h b/mm/slab.h
index 0446948c9c4e..4bcaa08320e6 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -410,8 +410,7 @@ static inline struct kmem_cache *virt_to_cache(const void *obj)
struct page *page;

page = virt_to_head_page(obj);
- if (WARN_ONCE(!PageSlab(compound_head(page)),
- "%s: Object is not a Slab page!\n",
+ if (WARN_ONCE(!PageSlab(page), "%s: Object is not a Slab page!\n",
__func__))
return NULL;
return page->slab_cache;
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 5f7063797f0e..ec2bb0beed75 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -564,7 +564,7 @@ bool kmem_valid_obj(void *object)
if (object < (void *)PAGE_SIZE || !virt_addr_valid(object))
return false;
page = virt_to_head_page(object);
- return PageSlab(compound_head(page));
+ return PageSlab(page);
}
EXPORT_SYMBOL_GPL(kmem_valid_obj);

@@ -594,7 +594,7 @@ void kmem_dump_obj(void *object)
if (WARN_ON_ONCE(!virt_addr_valid(object)))
return;
page = virt_to_head_page(object);
- if (WARN_ON_ONCE(!PageSlab(compound_head(page)))) {
+ if (WARN_ON_ONCE(!PageSlab(page))) {
pr_cont(" non-slab memory.\n");
return;
}
--
2.32.0