---
name: "page_cache_async_readahead"
section: "9"
platform: "linux"
package: "linux-manual-4.9"
version: "4.9.228-1"
release: "Debian 9 (Stretch)"
platforms: ["linux"]
url: "https://new.carta.tech/page_cache_async_readahead"
---

# page\_cache\_async\_readahead(9)

file readahead for marked pages

## NAME

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.

## COPYRIGHT