The patch titled
Subject: slab,slub: remove rcu_head size checks
has been added to the -mm tree. Its filename is
slabslub-remove-rcu_head-size-checks.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/slabslub-remove-rcu_head-size-checks.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/slabslub-remove-rcu_head-size-checks.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
Subject: 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@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
Acked-by: Christoph Lameter <cl@xxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Jérôme Glisse <jglisse@xxxxxxxxxx>
Cc: "Kirill A . Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Lai Jiangshan <jiangshanlai@xxxxxxxxx>
Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/slab.c | 2 --
mm/slub.c | 27 ++-------------------------
2 files changed, 2 insertions(+), 27 deletions(-)
diff -puN mm/slab.c~slabslub-remove-rcu_head-size-checks mm/slab.c
--- a/mm/slab.c~slabslub-remove-rcu_head-size-checks
+++ a/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 -puN mm/slub.c~slabslub-remove-rcu_head-size-checks mm/slub.c
--- a/mm/slub.c~slabslub-remove-rcu_head-size-checks
+++ a/mm/slub.c
@@ -1686,17 +1686,9 @@ static void __free_slab(struct kmem_cach
__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_hea
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_c
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) {
_
Patches currently in -mm which might be from mawilcox@xxxxxxxxxxxxx are
lib-test_bitmapc-fix-bitmap-optimisation-tests-to-report-errors-correctly.patch
slab-__gfp_zero-is-incompatible-with-a-constructor.patch
s390-use-_refcount-for-pgtables.patch
mm-split-page_type-out-from-_mapcount.patch
mm-mark-pages-in-use-for-page-tables.patch
mm-switch-s_mem-and-slab_cache-in-struct-page.patch
mm-move-private-union-within-struct-page.patch
mm-move-_refcount-out-of-struct-page-union.patch
mm-combine-first-three-unions-in-struct-page.patch
mm-use-page-deferred_list.patch
mm-move-lru-union-within-struct-page.patch
mm-combine-lru-and-main-union-in-struct-page.patch
mm-improve-struct-page-documentation.patch
mm-add-pt_mm-to-struct-page.patch
mm-add-hmm_data-to-struct-page.patch
slabslub-remove-rcu_head-size-checks.patch
slub-remove-kmem_cache-reserved.patch
slub-remove-reserved-file-from-sysfs.patch
mm-distinguish-vmalloc-pages.patch
ida-remove-simple_ida_lock.patch
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