page_cache_sync_readahead (9) - Linux Man Pages

page_cache_sync_readahead: generic file readahead

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.

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