From owner-freebsd-current@FreeBSD.ORG Fri Apr 28 01:01:48 2006 Return-Path: X-Original-To: freebsd-current@freebsd.org Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 77F8916A408 for ; Fri, 28 Apr 2006 01:01:48 +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 AB8DF43D53 for ; Fri, 28 Apr 2006 01:01:47 +0000 (GMT) (envelope-from kris@obsecurity.org) Received: from obsecurity.dyndns.org (elvis.mu.org [192.203.228.196]) by elvis.mu.org (Postfix) with ESMTP id 6FAAB1A4EB1; Thu, 27 Apr 2006 18:01:47 -0700 (PDT) Received: by obsecurity.dyndns.org (Postfix, from userid 1000) id 848BA55E60; Thu, 27 Apr 2006 21:01:46 -0400 (EDT) Date: Thu, 27 Apr 2006 21:01:46 -0400 From: Kris Kennaway To: "Brian K. White" Message-ID: <20060428010146.GA73203@xor.obsecurity.org> References: <20060427160536.M96305@atlantis.atlantis.dp.ua> <20060427181226.GA66431@xor.obsecurity.org> <44510CBE.6050102@sd2i.com> <44511E27.2070101@chillt.de> <02c301c66a5c$bafc7300$6500000a@venti> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="huq684BweRXVnRxX" Content-Disposition: inline In-Reply-To: <02c301c66a5c$bafc7300$6500000a@venti> User-Agent: Mutt/1.4.2.1i Cc: freebsd-current@freebsd.org Subject: Re: RELENG_4 -> 5 -> 6: significant performance regression X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 28 Apr 2006 01:01:48 -0000 --huq684BweRXVnRxX Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Apr 27, 2006 at 08:42:47PM -0400, Brian K. White wrote: >=20 > ----- Original Message -----=20 > From: "Bartosz Fabianowski" > To: > Cc: > Sent: Thursday, April 27, 2006 3:40 PM > Subject: Re: RELENG_4 -> 5 -> 6: significant performance regression >=20 >=20 > >>You wrote that Giant is needed in 6.0 and now you write it has been > >>removed. > > > >In 4.x, every UFS write requires the Giant lock. In 6.x, Giant is not=20 > >normally required, making file system operations faster. When you enable= =20 > >QUOTA, you basically get back to the 4.x behavior where Giant is needed= =20 > >for each write. This is why in 6.x UFS will normally be faster but if yo= u=20 > >enable QUOTA, you lose the newly gained performance again. >=20 > In that case the test was correct the question stands at least on that=20 > point. > If quota isn't mpsafe yet, that's fine. It just means that performance=20 > should still be only about the same as on 4 while quota is enabled. > Removing a feature you had before is no answer to this question. > Removing an expensive new feature that didn't exist before could be. The above isn't quite accurate because 4.x uses the spl model which means that interrupts may be serviced while other code is operating at a lower spl level. The OP still needs to test without quotas (and other changes mentioned) to see whether it has an impact on his benchmark. Kris --huq684BweRXVnRxX Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (FreeBSD) iD8DBQFEUWl5Wry0BWjoQKURAiTlAKC7QYpK87heskQ1gPl0DYwnc27d6ACgkNd/ 3iSSAZqYPuBxmYWLyArHC5s= =KTxH -----END PGP SIGNATURE----- --huq684BweRXVnRxX--