page.c File Reference

#include <linux/highmem.h>
#include <linux/gfp.h>
#include <linux/cpu.h>
#include <linux/export.h>
#include "rds.h"

Go to the source code of this file.

Data Structures
struct	rds_page_remainder

Functions
int	rds_page_copy_user (struct page *page, unsigned long offset, void __user *ptr, unsigned long bytes, int to_user)
	EXPORT_SYMBOL_GPL (rds_page_copy_user)
int	rds_page_remainder_alloc (struct scatterlist *scat, unsigned long bytes, gfp_t gfp)
	EXPORT_SYMBOL_GPL (rds_page_remainder_alloc)
void	rds_page_exit (void)

Function Documentation

EXPORT_SYMBOL_GPL

(

rds_page_copy_user

)

EXPORT_SYMBOL_GPL

(

rds_page_remainder_alloc

)

int rds_page_copy_user	(	struct page *	page,
		unsigned long	offset,
		void __user *	ptr,
		unsigned long	bytes,
		int	to_user
	)

Definition at line 56 of file page.c.

void rds_page_exit

(

void

)

Definition at line 207 of file page.c.

int rds_page_remainder_alloc	(	struct scatterlist *	scat,
		unsigned long	bytes,
		gfp_t	gfp
	)

rds_page_remainder_alloc - build up regions of a message.

: Scatter list for message : the number of bytes needed. : the waiting behaviour of the allocation

is always ored with __GFP_HIGHMEM. Callers must be prepared to kmap the pages, etc.

If is at least a full page then this just returns a page from alloc_page().

If is a partial page then this stores the unused region of the page in a per-cpu structure. Future partial-page allocations may be satisfied from that cached region. This lets us waste less memory on small allocations with minimal complexity. It works because the transmit path passes read-only page regions down to devices. They hold a page reference until they are done with the region.

Definition at line 97 of file page.c.