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authorMatthew Wilcox <mawilcox@microsoft.com>2018-06-08 03:09:05 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-06-08 03:34:37 +0300
commitbf68c214df6d73e85fc19b6bbcb642554b491b98 (patch)
tree75b27453d49cdba987a49559dbf1153b39ea339b /mm
parent50e7fbc3bf0c3e41af0075f17a9e4ddefa82e1b5 (diff)
downloadlinux-bf68c214df6d73e85fc19b6bbcb642554b491b98.tar.xz
slab,slub: remove rcu_head size checks
rcu_head may now grow larger than list_head without affecting slab or slub. Link: http://lkml.kernel.org/r/20180518194519.3820-15-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Christoph Lameter <cl@linux.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/slab.c2
-rw-r--r--mm/slub.c27
2 files changed, 2 insertions, 27 deletions
diff --git a/mm/slab.c b/mm/slab.c
index c1fe8099b3cd..36688f6c87eb 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1235,8 +1235,6 @@ void __init kmem_cache_init(void)
{
int i;
- BUILD_BUG_ON(sizeof(((struct page *)NULL)->lru) <
- sizeof(struct rcu_head));
kmem_cache = &kmem_cache_boot;
if (!IS_ENABLED(CONFIG_NUMA) || num_possible_nodes() == 1)
diff --git a/mm/slub.c b/mm/slub.c
index a96bf429af08..d5bddf0f4792 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1686,17 +1686,9 @@ static void __free_slab(struct kmem_cache *s, struct page *page)
__free_pages(page, order);
}
-#define need_reserve_slab_rcu \
- (sizeof(((struct page *)NULL)->lru) < sizeof(struct rcu_head))
-
static void rcu_free_slab(struct rcu_head *h)
{
- struct page *page;
-
- if (need_reserve_slab_rcu)
- page = virt_to_head_page(h);
- else
- page = container_of((struct list_head *)h, struct page, lru);
+ struct page *page = container_of(h, struct page, rcu_head);
__free_slab(page->slab_cache, page);
}
@@ -1704,19 +1696,7 @@ static void rcu_free_slab(struct rcu_head *h)
static void free_slab(struct kmem_cache *s, struct page *page)
{
if (unlikely(s->flags & SLAB_TYPESAFE_BY_RCU)) {
- struct rcu_head *head;
-
- if (need_reserve_slab_rcu) {
- int order = compound_order(page);
- int offset = (PAGE_SIZE << order) - s->reserved;
-
- VM_BUG_ON(s->reserved != sizeof(*head));
- head = page_address(page) + offset;
- } else {
- head = &page->rcu_head;
- }
-
- call_rcu(head, rcu_free_slab);
+ call_rcu(&page->rcu_head, rcu_free_slab);
} else
__free_slab(s, page);
}
@@ -3583,9 +3563,6 @@ static int kmem_cache_open(struct kmem_cache *s, slab_flags_t flags)
s->random = get_random_long();
#endif
- if (need_reserve_slab_rcu && (s->flags & SLAB_TYPESAFE_BY_RCU))
- s->reserved = sizeof(struct rcu_head);
-
if (!calculate_sizes(s, -1))
goto error;
if (disable_higher_order_debug) {