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LAT_PAGEFAULT(8)		    LMBENCH		      LAT_PAGEFAULT(8)

NAME
       lat_pagefault - measure the cost	of pagefaulting	pages from a file

SYNOPSIS
       lat_pagefault  [	-P _parallelism_ ] [ -W	_warmups_ ] [ -N _repetitions_
       ] file [	file....  ]

DESCRIPTION
       lat_pagefault times how fast a page of a	file can be faulted  in.   The
       file is flushed from (local) memory by using the	msync()	interface with
       the invalidate flag set.	 (Note that NFS	does not send  this  over  the
       wire  so	this makes for a handy way to measure the cost of going	across
       the wire.)

       The benchmark maps in the entire	file and the  access  pages  backwards
       using a stride of 256K kilobytes.

OUTPUT
       Output  format  is below; it prints the average cost of page faulting a
       page.

       Pagefaults on <file>: <d> usecs

BUGS
       Using a stride of 256K may be a bad idea	because	SCSI  controllers  may
       have caches bigger than that.

ACKNOWLEDGEMENT
       Funding	for the	development of this tool was provided by Sun Microsys-
       tems Computer Corporation.

SEE ALSO
       lmbench(8).

AUTHOR
       Carl Staelin and	Larry McVoy

       Comments, suggestions, and bug reports are always welcome.

(c)1994	Larry McVoy		    $Date$		      LAT_PAGEFAULT(8)

NAME | SYNOPSIS | DESCRIPTION | OUTPUT | BUGS | ACKNOWLEDGEMENT | SEE ALSO | AUTHOR

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