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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)

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<https://man.freebsd.org/cgi/man.cgi?query=lat_pagefault&sektion=8&manpath=FreeBSD+Ports+15.0>

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