Name

page_cache_sync_readahead — generic file readahead

Synopsis

void page_cache_sync_readahead (struct address_space *  mapping,
 struct file_ra_state *  ra,
 struct file *  filp,
 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

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_sync_readahead should be called when a cache miss happened: it will submit the read. The readahead logic may decide to piggyback more pages onto the read request if access patterns suggest it will improve performance.