page_cache_async_readahead (9) Linux Manual Page
page_cache_async_readahead – file readahead for marked pages
Synopsis
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);Arguments
mapping
-
- address_space which holds the pagecache and I/O vectors
ra
- file_ra_state which holds the readahead state
filp
- passed on to ->readpage and ->readpages
page
- the page at offset which has the PG_readahead flag set
offset
- start offset into mapping, in pagecache page-sized units
req_size
- hint: total size of the read which the caller is performing in pagecache pages
Description
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.