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| author | Lai Jiangshan <laijs@cn.fujitsu.com> | 2011-03-10 15:22:24 +0800 |
|---|---|---|
| committer | Pekka Enberg <penberg@kernel.org> | 2011-03-11 18:06:35 +0200 |
| commit | 5bfe53a77e8a3ffce4a10003c75f464a138e272d (patch) | |
| tree | 4e46dc4a8e7d2cf83e330d63ab62815718fcec11 /mm/slab.c | |
| parent | da9a638c6f8fc0633fa94a334f1c053f5e307177 (diff) | |
| download | lwn-5bfe53a77e8a3ffce4a10003c75f464a138e272d.tar.gz lwn-5bfe53a77e8a3ffce4a10003c75f464a138e272d.zip | |
slab,rcu: don't assume the size of struct rcu_head
The size of struct rcu_head may be changed. When it becomes larger,
it may pollute the data after struct slab.
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Diffstat (limited to 'mm/slab.c')
| -rw-r--r-- | mm/slab.c | 39 |
1 files changed, 21 insertions, 18 deletions
diff --git a/mm/slab.c b/mm/slab.c index 37961d1f584f..52cf0b4634d4 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -191,22 +191,6 @@ typedef unsigned int kmem_bufctl_t; #define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-3) /* - * struct slab - * - * Manages the objs in a slab. Placed either at the beginning of mem allocated - * for a slab, or allocated from an general cache. - * Slabs are chained into three list: fully used, partial, fully free slabs. - */ -struct slab { - struct list_head list; - unsigned long colouroff; - void *s_mem; /* including colour offset */ - unsigned int inuse; /* num of objs active in slab */ - kmem_bufctl_t free; - unsigned short nodeid; -}; - -/* * struct slab_rcu * * slab_destroy on a SLAB_DESTROY_BY_RCU cache uses this structure to @@ -219,8 +203,6 @@ struct slab { * * rcu_read_lock before reading the address, then rcu_read_unlock after * taking the spinlock within the structure expected at that address. - * - * We assume struct slab_rcu can overlay struct slab when destroying. */ struct slab_rcu { struct rcu_head head; @@ -229,6 +211,27 @@ struct slab_rcu { }; /* + * struct slab + * + * Manages the objs in a slab. Placed either at the beginning of mem allocated + * for a slab, or allocated from an general cache. + * Slabs are chained into three list: fully used, partial, fully free slabs. + */ +struct slab { + union { + struct { + struct list_head list; + unsigned long colouroff; + void *s_mem; /* including colour offset */ + unsigned int inuse; /* num of objs active in slab */ + kmem_bufctl_t free; + unsigned short nodeid; + }; + struct slab_rcu __slab_cover_slab_rcu; + }; +}; + +/* * struct array_cache * * Purpose: |