mm: add a "struct page_frag" type containing a page, offset and length

A few network drivers currently use skb_frag_struct for this purpose but I have
patches which add additional fields and semantics there which these other uses
do not want.

A structure for reference sub-page regions seems like a generally useful thing
so do so instead of adding a network subsystem specific structure.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Jens Axboe <jaxboe@fusionio.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ian Campbell 2011-10-20 04:58:32 -04:00 committed by David S. Miller
parent 90278c9ffb
commit 30d3c128ea

View File

@ -135,6 +135,17 @@ struct page {
#endif
;
struct page_frag {
struct page *page;
#if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
__u32 offset;
__u32 size;
#else
__u16 offset;
__u16 size;
#endif
};
typedef unsigned long __nocast vm_flags_t;
/*