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author | 2022-11-10 10:42:34 +0100 | |
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committer | 2022-11-21 10:36:09 +0100 | |
commit | 76537db3b95cbf5d0189ce185c16db9f93017021 (patch) | |
tree | a09d81a797d52a9a64da0470ec25997b81d8499e /mm/slab.h | |
parent | Merge branch 'slab/for-6.2/tools' into slab/for-next (diff) | |
parent | mm/sl[au]b: rearrange struct slab fields to allow larger rcu_head (diff) | |
download | linux-76537db3b95cbf5d0189ce185c16db9f93017021.tar.gz linux-76537db3b95cbf5d0189ce185c16db9f93017021.tar.bz2 linux-76537db3b95cbf5d0189ce185c16db9f93017021.zip |
Merge branch 'slab/for-6.2/fit_rcu_head' into slab/for-next
A series by myself to reorder fields in struct slab to allow the
embedded rcu_head to grow (for debugging purposes). Requires changes to
isolate_movable_page() to skip slab pages which can otherwise become
false-positive __PageMovable due to its use of low bits in
page->mapping.
Diffstat (limited to 'mm/slab.h')
-rw-r--r-- | mm/slab.h | 54 |
1 files changed, 32 insertions, 22 deletions
diff --git a/mm/slab.h b/mm/slab.h index 19e1baac807c..8c4aafb00bd6 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -11,37 +11,43 @@ struct slab { #if defined(CONFIG_SLAB) + struct kmem_cache *slab_cache; union { - struct list_head slab_list; + struct { + struct list_head slab_list; + void *freelist; /* array of free object indexes */ + void *s_mem; /* first object */ + }; struct rcu_head rcu_head; }; - struct kmem_cache *slab_cache; - void *freelist; /* array of free object indexes */ - void *s_mem; /* first object */ unsigned int active; #elif defined(CONFIG_SLUB) - union { - struct list_head slab_list; - struct rcu_head rcu_head; -#ifdef CONFIG_SLUB_CPU_PARTIAL - struct { - struct slab *next; - int slabs; /* Nr of slabs left */ - }; -#endif - }; struct kmem_cache *slab_cache; - /* Double-word boundary */ - void *freelist; /* first free object */ union { - unsigned long counters; struct { - unsigned inuse:16; - unsigned objects:15; - unsigned frozen:1; + union { + struct list_head slab_list; +#ifdef CONFIG_SLUB_CPU_PARTIAL + struct { + struct slab *next; + int slabs; /* Nr of slabs left */ + }; +#endif + }; + /* Double-word boundary */ + void *freelist; /* first free object */ + union { + unsigned long counters; + struct { + unsigned inuse:16; + unsigned objects:15; + unsigned frozen:1; + }; + }; }; + struct rcu_head rcu_head; }; unsigned int __unused; @@ -66,9 +72,10 @@ struct slab { #define SLAB_MATCH(pg, sl) \ static_assert(offsetof(struct page, pg) == offsetof(struct slab, sl)) SLAB_MATCH(flags, __page_flags); -SLAB_MATCH(compound_head, slab_list); /* Ensure bit 0 is clear */ #ifndef CONFIG_SLOB -SLAB_MATCH(rcu_head, rcu_head); +SLAB_MATCH(compound_head, slab_cache); /* Ensure bit 0 is clear */ +#else +SLAB_MATCH(compound_head, slab_list); /* Ensure bit 0 is clear */ #endif SLAB_MATCH(_refcount, __page_refcount); #ifdef CONFIG_MEMCG @@ -76,6 +83,9 @@ SLAB_MATCH(memcg_data, memcg_data); #endif #undef SLAB_MATCH static_assert(sizeof(struct slab) <= sizeof(struct page)); +#if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && defined(CONFIG_SLUB) +static_assert(IS_ALIGNED(offsetof(struct slab, freelist), 2*sizeof(void *))); +#endif /** * folio_slab - Converts from folio to slab. |