Re: [PATCH 04/10] mm: slub: add knowledge of reserve pages

Peter Zijlstra
2007-08-20T09:17:35Z

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On Mon, 2007-08-20 at 12:12 +0300, Pekka J Enberg wrote:
> Hi Peter,
>
> On Mon, 20 Aug 2007, Peter Zijlstra wrote:
> > -static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
> > +static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node, int *reserve)
> > {
>
> [snip]
>
> > + *reserve = page->reserve;
>
> Any reason why the callers that are actually interested in this don't do
> page->reserve on their own?

because new_slab() destroys the content?

struct page {
...
union {
pgoff_t index; /* Our offset within mapping. */
void *freelist; /* SLUB: freelist req. slab lock */
int reserve; /* page_alloc: page is a reserve page */
atomic_t frag_count; /* skb fragment use count */
};
...
};

static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node, int *reserve)
{
...
*reserve = page->reserve;
...
page->freelist = start;
...
}

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