From owner-freebsd-stable@FreeBSD.ORG Wed Aug 15 17:42:19 2007 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 7C26816A418 for ; Wed, 15 Aug 2007 17:42:19 +0000 (UTC) (envelope-from kris@obsecurity.org) Received: from elvis.mu.org (elvis.mu.org [192.203.228.196]) by mx1.freebsd.org (Postfix) with ESMTP id 61B9D13C494 for ; Wed, 15 Aug 2007 17:42:19 +0000 (UTC) (envelope-from kris@obsecurity.org) Received: from rot26.obsecurity.org (elvis.mu.org [192.203.228.196]) by elvis.mu.org (Postfix) with ESMTP id 7F39C1A4D84; Wed, 15 Aug 2007 10:40:51 -0700 (PDT) Received: by rot26.obsecurity.org (Postfix, from userid 1001) id 7BAD9C3EC; Wed, 15 Aug 2007 13:42:18 -0400 (EDT) Date: Wed, 15 Aug 2007 13:42:18 -0400 From: Kris Kennaway To: Artem Kuchin Message-ID: <20070815174218.GB71910@rot26.obsecurity.org> References: <000b01c7df5f$0ee4eec0$0c00a8c0@Artem> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="9amGYk9869ThD9tj" Content-Disposition: inline In-Reply-To: <000b01c7df5f$0ee4eec0$0c00a8c0@Artem> User-Agent: Mutt/1.4.2.3i Cc: freebsd-stable@freebsd.org Subject: Re: twa is giant locked in 7-Current or everywhere? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 15 Aug 2007 17:42:19 -0000 --9amGYk9869ThD9tj Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Aug 15, 2007 at 09:09:33PM +0400, Artem Kuchin wrote: > Hi! >=20 > When i installed twas driver on 6.2-STABLE it said > [FAST] >=20 > i presumed that it measn that twa is giant-lock free. >=20 > Now, after installing 7-CURRENT i see >=20 > Aug 15 17:00:02 omni3 kernel: 3ware device driver for 9000 series storage= =20 > controllers, version: 3.70.03.007 > Aug 15 17:00:02 omni3 kernel: twa0: <3ware 9000 series Storage Controller= >=20 > port 0x3000-0x30ff mem 0x88000000-0x89ffffff,0x8a200000-0x8a200fff irq 16= =20 > at devic > Aug 15 17:00:02 omni3 kernel: twa0: [GIANT-LOCKED] > Aug 15 17:00:02 omni3 kernel: twa0: [ITHREAD] >=20 >=20 > So, it says GIANT-LOCKED and then ITHREAD. >=20 > Apparently, i have no real understaning what those words mean. > COuld anyone explain the meaning of >=20 > FAST > ITHREAD >=20 > Giant-locked is self explanatory and.. bad. I think 6.x doesn't display the GIANT-LOCKED messages because users were freaking out too much after they were added at an earlier point in 6.x development ("Q: why is this driver suddenly giant locked?" "A: It's always been giant locked, now this fact is displayed as a note to developers."). While it's true that a non-giant locked driver would be better, it's not as bad as you might think because almost nothing else requires giant for most workloads thesedays (see http://wiki.freebsd.org/SMPTODO), so in those workloads performance will not be worse because of it. If you are really bothered by this you can enable mutex profiling to check how much of a problem it is for you. Kris --9amGYk9869ThD9tj Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4 (FreeBSD) iD8DBQFGwzr6Wry0BWjoQKURAv/3AJ9TKDV1HJqsGssQg5PRc4fvpDIm0QCeNTTx NxeJgbo66J+LmKZuCvd5bvc= =4Ahm -----END PGP SIGNATURE----- --9amGYk9869ThD9tj--