>Number:         25640
>Category:       kern
>Synopsis:       physio doesn't make the pages dirty
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed May 19 13:51:01 UTC 2004
>Closed-Date:
>Last-Modified:
>Originator:     YAMAMOTO Takashi <yamt@mwd.biglobe.ne.jp>
>Release:        NetBSD 2.0E
>Organization:

>Environment:
	
	
System: NetBSD kaeru 2.0E NetBSD 2.0E (build.kaeru) #1310: Wed May 19 21:29:48 JST 2004 takashi@kaeru:/usr/home/takashi/work/kernel/build.kaeru i386
Architecture: i386
Machine: i386
>Description:
	from Stephan Uphoff
	(http://mail-index.NetBSD.org/tech-kern/2003/07/11/0012.html)

> Read operations from devices using physio will not cause
> pages associated with the buffer to be marked dirty.
> Because of this changed state (data read from the device) can get 
> lost later.
> Fortunately data loss will not happen with anonymous memory as wiring releases
> any swap space owned by an anonymous page. (physio wires the pages)
> This can however cause problems for programs using device reads into
> mmaped files.

>How-To-Repeat:
	
>Fix:
	
>Release-Note:
>Audit-Trail:
>Unformatted: