Re: Improvement on memory subsystem

["yunfeng zhang" <zyf.zeroos@gmail.com>]

2006/7/19, Pekka Enberg <penberg@cs.helsinki.fi>:
> On 7/18/06, yunfeng zhang <zyf.zeroos@gmail.com> wrote:
> > 3. All slabs are all off-slab type. Store slab instance in page structure.
>
> Not sure what you mean. We need much more than sizeof(struct page) for
> slab management. Hmm?
>

Current page struct is just like this
struct page {
	unsigned long flags;
	atomic_t _count;
	atomic_t _mapcount;
	union {
		struct {
			unsigned long private;
			struct address_space *mapping;
		};
#if NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS
		spinlock_t ptl;
#endif
	};
	pgoff_t index;
	struct list_head lru;
#if defined(WANT_PAGE_VIRTUAL)
	void *virtual;
#endif /* WANT_PAGE_VIRTUAL */
};
Most fields in the page structure is used for user page, to a core
slab page, these aren't touched at all.
So I think we should define a union
struct page {
	unsigned long flags;
	struct slab {
		struct list_head list;
		unsigned long colouroff;
		void *s_mem;
		unsigned int inuse;
		kmem_bufctl_t free;
		unsigned short nodeid;
	};
};