Path: utzoo!utgpu!watmath!att!tut.cis.ohio-state.edu!cs.utexas.edu!uunet!zephyr.ens.tek.com!orca!frip!andrew
From: andrew@frip.WV.TEK.COM (Andrew Klossner)
Newsgroups: comp.arch
Subject: TLB traffic reports (was Re: Cycle Counter)
Message-ID: <4221@orca.WV.TEK.COM>
Date: 14 Aug 89 20:09:02 GMT
References: <559@halley.UUCP> <5818@pt.cs.cmu.edu>
Sender: nobody@orca.WV.TEK.COM
Distribution: comp
Organization: Tektronix, Wilsonville, Oregon
Lines: 15
[]
"When a programmer suspects thrashing, the average OS can help
by reporting paging rates, task switch counts, interrupt load,
ethernet packets, and so on. The OS typically is unable to
report on cache traffic or on TLB traffic."
An OS hacker could get most of the way there without hardware assist by
making regular (once per clock tick?) sweeps through the page tables,
noting and clearing the "page used" bits and flushing the TLB. For
example, it wouldn't take more than a couple of days to fit something
like this into Unix system V, including the statistic reporting utility.
-=- Andrew Klossner (uunet!tektronix!frip.WV.TEK!andrew) [UUCP]
(andrew%frip.wv.tek.com@relay.cs.net) [ARPA]