From owner-freebsd-arm@FreeBSD.ORG Wed Oct 15 20:45:18 2008 Return-Path: Delivered-To: freebsd-arm@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 46F071065691; Wed, 15 Oct 2008 20:45:18 +0000 (UTC) (envelope-from stas@FreeBSD.org) Received: from smtp.ht-systems.ru (mr0.ht-systems.ru [78.110.50.55]) by mx1.freebsd.org (Postfix) with ESMTP id AE9918FC18; Wed, 15 Oct 2008 20:45:17 +0000 (UTC) (envelope-from stas@FreeBSD.org) Received: from [85.21.245.235] (helo=orion.SpringDaemons.com) by smtp.ht-systems.ru with esmtpa (Exim 4.62) (envelope-from ) id 1KqDF4-0001Jc-Sf; Thu, 16 Oct 2008 00:45:14 +0400 Received: from orion (localhost [127.0.0.1]) by orion.SpringDaemons.com (Postfix) with SMTP id 3410E398F1; Thu, 16 Oct 2008 00:45:53 +0400 (MSD) Date: Thu, 16 Oct 2008 00:45:48 +0400 From: Stanislav Sedov To: Alexander Motin Message-Id: <20081016004548.437cba9d.stas@FreeBSD.org> In-Reply-To: <48F651A7.3040001@FreeBSD.org> References: <5f67a8c40810052226k3070a11ah463a819c677f6307@mail.gmail.com> <20081008113848.c9b44354.webmaster@kibab.com> <20081012171201.da4da754.webmaster@kibab.com> <20081013.110310.-1622595361.imp@bsdimp.com> <48F651A7.3040001@FreeBSD.org> Organization: The FreeBSD Project X-XMPP: ssedov@jabber.ru X-Voice: +7 916 849 20 23 X-PGP-Fingerprint: F21E D6CC 5626 9609 6CE2 A385 2BF5 5993 EB26 9581 X-Mailer: carrier-pigeon Mime-Version: 1.0 Content-Type: multipart/signed; protocol="application/pgp-signature"; micalg="PGP-SHA1"; boundary="Signature=_Thu__16_Oct_2008_00_45_48_+0400_gpvxnSXKe9UYcK1e" Cc: zbeeble@gmail.com, freebsd-arm@freebsd.org, freebsd-current@freebsd.org, freebsd-mobile@freebsd.org Subject: Re: RFC: PCI SD host controller driver & mmc/mmcsd modules improvements X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Porting FreeBSD to the StrongARM Processor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 15 Oct 2008 20:45:18 -0000 --Signature=_Thu__16_Oct_2008_00_45_48_+0400_gpvxnSXKe9UYcK1e Content-Type: text/plain; charset=US-ASCII Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, 15 Oct 2008 23:25:11 +0300 Alexander Motin mentioned: >=20 > Completely fortunate I have noticed that number of iterations depends on= =20 > my laptop power source. After small investigation I have found that it=20 > actually depends on dev.cpu.0.freq value. With default value 2400 I have= =20 > only several iterations. But every double frequency decrease doubles=20 > iteration count. With minimum value 100MHz I have more then 100=20 > iterations. Same time it doesn't looks like this time is a real wall=20 > time. It looks like DELAY() used in a loop has some problems with time=20 > counting. >=20 What do you mean? DELAY(9) on your laptop doesn't correspond to the real time? AFAIK, DELAY(9) relies on current timecounter for time accountiong, so there might be problems with it. Have you tried switching the kern.timecounter.hardware sysctl to see if it will affect results? --=20 Stanislav Sedov ST4096-RIPE --Signature=_Thu__16_Oct_2008_00_45_48_+0400_gpvxnSXKe9UYcK1e Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (FreeBSD) iEYEARECAAYFAkj2VoEACgkQK/VZk+smlYHA5wCeIgg4IPiIQihQ3sVJ5IzawUaK nGgAnid2uyjyJbK0jty1Tp3zl+gXNRn7 =WF8Y -----END PGP SIGNATURE----- --Signature=_Thu__16_Oct_2008_00_45_48_+0400_gpvxnSXKe9UYcK1e--