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From: Nigel Cunningham <nigel@nigel.suspend2.net>
To: Rene Herman <rene.herman@gmail.com>
Cc: Linux Kernel <linux-kernel@vger.kernel.org>,
	dpreed@reed.com, Alan Cox <alan@lxorguk.ukuu.org.uk>,
	pavel@ucw.cz, andi@firstfloor.org, rol@as2917.net,
	Krzysztof Halasa <khc@pm.waw.pl>,
	david@davidnewall.com, hpa@zytor.com, john@stoffel.org,
	linux-os@analogic.com
Subject: Re: [RFT] Port 0x80 I/O speed
Date: Wed, 12 Dec 2007 13:07:47 +1100	[thread overview]
Message-ID: <475F4273.80905@nigel.suspend2.net> (raw)
In-Reply-To: <475F24C1.2050807@keyaccess.nl>

Rene Herman wrote:
> On 12-12-07 00:55, Nigel Cunningham wrote:
> 
>> (AMD 1.8GHz Turion, running at 800MHz. ATI RS480 - Mitac 8350 mobo)
>>
>> nigel@home:~/Downloads$ gcc port80.c -o port80
>> nigel@home:~/Downloads$ sudo ./port80
>> cycles: out 1235, in 1207
> 
> Looking good.
> 
>> nigel@home:~/Downloads$ gcc -O2 port80.c -o port80
>> nigel@home:~/Downloads$ sudo ./port80
>> cycles: out 1844674407370794, in 1844674407369408
> 
> Obviously not. I suppose this changes with -m32 on the GCC command line?
> (sorry for missing that, I have no 64-bit machines).

Yes, it does:

nigel@home:~/Downloads$ gcc -m32 -o port80 port80.c
nigel@home:~/Downloads$ sudo ./port80
cycles: out 1231, in 1208
nigel@home:~/Downloads$ sudo ./port80
cycles: out 1233, in 1210

Incidentally:

nigel@home:~/Downloads$ processor_speed

(A little script I made because my lappy does a solid lock every now and
then that seems to be cpu-freq related - locking it to one frequency
makes the lock far less common).

Speed is now 1800000.
nigel@home:~/Downloads$ sudo ./port80
cycles: out 2472, in 2505
nigel@home:~/Downloads$ sudo ./port80
cycles: out 2489, in 2515
nigel@home:~/Downloads$ sudo ./port80
cycles: out 2481, in 2503
nigel@home:~/Downloads$ sudo ./port80
cycles: out 2476, in 2507

So the same effect Maxim reported is seen here.

Regards,

Nigel

  reply	other threads:[~2007-12-12  2:08 UTC|newest]

Thread overview: 68+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-12-11 23:31 [RFT] Port 0x80 I/O speed Rene Herman
2007-12-11 23:40 ` Maxim Levitsky
2007-12-11 23:44   ` Rene Herman
2007-12-12  0:14     ` Maxim Levitsky
2007-12-12  0:27       ` Rene Herman
2007-12-11 23:43 ` Alejandro Riveira Fernández
2007-12-11 23:51   ` Rene Herman
2007-12-12  0:09     ` Alejandro Riveira Fernández
2007-12-12  0:16       ` Rene Herman
2007-12-12 11:43         ` Alejandro Riveira Fernández
2007-12-12 21:02         ` H. Peter Anvin
     [not found]   ` <Pine.LNX.4.61.0712120753210.4443@chaos.analogic.com>
2007-12-12 13:20     ` Rene Herman
2007-12-12 13:23       ` linux-os (Dick Johnson)
2007-12-11 23:55 ` Nigel Cunningham
2007-12-12  0:01   ` Rene Herman
2007-12-12  2:07     ` Nigel Cunningham [this message]
2007-12-12  1:19 ` Alistair John Strachan
2007-12-12  1:28 ` Randy Dunlap
2007-12-12  1:40 ` Mike Lampard
2007-12-12  5:23 ` Kyle McMartin
2007-12-12  7:18   ` Rene Herman
2007-12-13  2:41     ` H. Peter Anvin
2007-12-12 19:25   ` H. Peter Anvin
2007-12-12 19:32     ` Andi Kleen
2007-12-12 19:43       ` H. Peter Anvin
2007-12-12  8:17 ` Paolo Ornati
2007-12-12  8:38   ` Edwin de Caluwé
2007-12-12  8:35 ` Dave Young
2007-12-12  8:48 ` Jiri Slaby
2007-12-12 11:25   ` Jiri Slaby
2007-12-12 15:50     ` Rene Herman
2007-12-12 15:53     ` Rene Herman
2007-12-12 18:44     ` H. Peter Anvin
2007-12-12 19:19       ` Rene Herman
2007-12-13 15:19         ` Jiri Slaby
2007-12-12  8:59 ` Juergen Beisert
2007-12-12 14:30   ` Rene Herman
2007-12-12 15:12     ` Juergen Beisert
2007-12-12  9:55 ` Luciano Rocha
2007-12-12  9:57 ` Romano Giannetti
2007-12-12 16:27   ` Rene Herman
2007-12-12 10:28 ` Peter Zijlstra
2007-12-12 10:34 ` Dave Haywood
2007-12-12 11:57 ` Ville Syrjälä
2007-12-13 16:42   ` Ville Syrjälä
2007-12-12 16:16 ` John Stoffel
2007-12-12 16:39 ` Olivér Pintér
2007-12-12 16:53 ` Ondrej Zary
2007-12-12 17:00   ` H. Peter Anvin
2007-12-12 16:59 ` Cyrill Gorcunov
2007-12-12 17:27 ` Török Edwin
2007-12-12 18:54   ` David P. Reed
2007-12-12 18:39 ` SL Baur
2007-12-12 19:06   ` Rene Herman
2007-12-12 21:32 ` Jesper Juhl
2007-12-12 23:54 ` Jan Engelhardt
2007-12-13  0:13   ` Jan Engelhardt
2007-12-13  2:06   ` H. Peter Anvin
2007-12-22 22:27 ` Bauke Jan Douma
2007-12-12  5:06 Chris Holvenstot
2007-12-12 11:20 linux
2007-12-12 12:35 ` Paolo Ornati
2007-12-12 14:48 ` Rene Herman
     [not found] <9zmRR-3pA-25@gated-at.bofh.it>
2007-12-13 16:27 ` James Kosin
2007-12-13 22:07   ` Rene Herman
2007-12-13 22:30     ` Jesper Juhl
2007-12-13 22:37       ` Rene Herman
     [not found] <9A0cz-7xy-13@gated-at.bofh.it>
     [not found] ` <9A0cz-7xy-11@gated-at.bofh.it>
     [not found]   ` <9A4pU-69z-15@gated-at.bofh.it>
2007-12-14 14:08     ` James Kosin

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