Messages in this thread Patch in this message | | | Date | Tue, 03 Mar 2009 21:44:34 +0800 | From | Lai Jiangshan <> | Subject | [PATCH -mm 4/6] slqb: record slab's start address in slqb_page |
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slqb's slab is coloring, it's will be useful that record the color value or start address in struct slqb_page.
This fix adds a field in struct slqb_page to record slab's start address, It will be used by kfree_rcu().
struct slqb_page has a field: struct kmem_cache_list *list;
the corresponding field in struct page is:
union { struct { unsigned long private; struct address_space *mapping; }; struct kmem_cache *slab; struct page *first_page; };
It's large than 'struct kmem_cache_list *list;' *So we are safe to add a field in struct page.*
(This field will not become a burden in future:) struct page is very small, this fix uses the last room of struct page. But if we have to add a more important field in struct slqb_page in future, We can record slab's color value in slqb_page instead of start address. like this: struct { unsigned long flags; atomic_t _count; u16 inuse; /* use u16 instead */ u16 color; /* of unsigned int */ void *a_more_important_field; struct kmem_cache_list *list; void **freelist; union { struct list_head lru; struct rcu_head rcu_head; }; };
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> --- diff --git a/mm/slqb.c b/mm/slqb.c index 48bdf3b..c258ddc 100644 --- a/mm/slqb.c +++ b/mm/slqb.c @@ -41,6 +41,7 @@ struct slqb_page { unsigned long flags; /* mandatory */ atomic_t _count; /* mandatory */ unsigned int inuse; /* Nr of objects */ + void *s_mem; /* start address */ struct kmem_cache_list *list; /* Pointer to list */ void **freelist; /* LIFO freelist */ union { @@ -1010,6 +1011,7 @@ static struct slqb_page *new_slab_page(struct kmem_cache *s, } set_freepointer(s, last, NULL); + page->s_mem = start; page->freelist = start; page->inuse = 0; out:
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