amd64/152405: wrong user time is reported when CPU frequency throttled.

[Andriy Gapon]

The following reply was made to PR amd64/152405; it has been noted by GNATS.

From: Andriy Gapon <avg at freebsd.org>
To: =?ISO-2022-JP?B?IktPSUUgSGlkZXRha2EgKBskQjhxOT4xUU40IXc/dE19NTs4JhsoQg==?=
 =?ISO-2022-JP?B?KSI=?= <koie at suri.co.jp>
Cc: bug-followup at freebsd.org
Subject: Re: amd64/152405: wrong user time is reported when CPU frequency
 throttled.
Date: Wed, 24 Nov 2010 11:31:38 +0200

 on 24/11/2010 09:17 KOIE Hidetaka ($B8q9>1QN4!w?tM}5;8&(B) said the following:
 >     % sudo sysctl kern.eventtimer.timer="i8254"
 >     Password:
 >     kern.eventtimer.timer: LAPIC -> i8254
 >     % sudo sysctl dev.cpu.0.freq=1800
 >     dev.cpu.0.freq: 1800 -> 1800
 >     % time ./loop
 >     ffffffff
 >     0.000u 4.773s 0:00.08 5962.5%   0+0k 0+0io 0pf+0w
 >     % sudo sysctl dev.cpu.0.freq=1000
 >     dev.cpu.0.freq: 1800 -> 1000
 >     % time ./loop
 >     ffffffff
 >     0.000u 4.773s 0:00.21 2271.4%   0+0k 0+0io 0pf+0w
 >     % sleep 1
 >     ("sleep" had returned after sysctl kern.eventtimer.timer="LAPIC" on another terminal)
 >     %
 > 
 > NOTE: user time is 0, system time is too long, and elapsed time is too short.
 > 
 > And, wall-clock has been slow...
 >     % ssh my-server date ; env LANG=C date
 >     Wed Nov 24 16:03:11 JST 2010
 >     Wed Nov 24 16:01:15 JST 2010
 
 
 Can you try to boot with kern.eventtimer.timer="i8254" in loader.conf?
 
 -- 
 Andriy Gapon