page_cache_async_readahead — file readahead for marked pages
void page_cache_async_readahead ( | struct address_space * mapping, |
| struct file_ra_state * ra, | |
| struct file * filp, | |
| struct page * page, | |
| pgoff_t offset, | |
unsigned long req_size); |
struct address_space * mappingaddress_space which holds the pagecache and I/O vectors
struct file_ra_state * rafile_ra_state which holds the readahead state
struct file * filp
passed on to ->readpage and ->readpages
struct page * page
the page at offset which has the PG_readahead flag set
pgoff_t offset
start offset into mapping, in pagecache page-sized units
unsigned long req_sizehint: total size of the read which the caller is performing in pagecache pages
page_cache_async_readahead should be called when a page is used which
has the PG_readahead flag; this is a marker to suggest that the application
has used up enough of the readahead window that we should start pulling in
more pages.