From owner-freebsd-stable@FreeBSD.ORG Sat Dec 22 05:37:40 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 1996D16A419; Sat, 22 Dec 2007 05:37:40 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from relay02.kiev.sovam.com (relay02.kiev.sovam.com [62.64.120.197]) by mx1.freebsd.org (Postfix) with ESMTP id 9F86413C43E; Sat, 22 Dec 2007 05:37:39 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from [212.82.216.226] (helo=deviant.kiev.zoral.com.ua) by relay02.kiev.sovam.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.67) (envelope-from ) id 1J5x3I-00003U-CG; Sat, 22 Dec 2007 07:37:38 +0200 Received: from deviant.kiev.zoral.com.ua (kostik@localhost [127.0.0.1]) by deviant.kiev.zoral.com.ua (8.14.2/8.14.2) with ESMTP id lBM5bXmS082494; Sat, 22 Dec 2007 07:37:33 +0200 (EET) (envelope-from kostikbel@gmail.com) Received: (from kostik@localhost) by deviant.kiev.zoral.com.ua (8.14.2/8.14.2/Submit) id lBM5bW0G082493; Sat, 22 Dec 2007 07:37:32 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: deviant.kiev.zoral.com.ua: kostik set sender to kostikbel@gmail.com using -f Date: Sat, 22 Dec 2007 07:37:32 +0200 From: Kostik Belousov To: Alfred Perlstein Message-ID: <20071222053732.GR57756@deviant.kiev.zoral.com.ua> References: <20071217102433.GQ25053@tnn.dglawrence.com> <20071220011626.U928@besplex.bde.org> <814DB7A9-E64F-4BCA-A502-AB5A6E0297D3@eng.oar.net> <20071219171331.GH25053@tnn.dglawrence.com> <20071221200810.GY16982@elvis.mu.org> <20071221234347.GS25053@tnn.dglawrence.com> <20071222002432.GK16982@elvis.mu.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="soWJpSPh+l8Y6Fy7" Content-Disposition: inline In-Reply-To: <20071222002432.GK16982@elvis.mu.org> User-Agent: Mutt/1.4.2.3i X-Scanner-Signature: f2683d8df775da069012ccac6e6e6321 X-DrWeb-checked: yes X-SpamTest-Envelope-From: kostikbel@gmail.com X-SpamTest-Group-ID: 00000000 X-SpamTest-Info: Profiles 1938 [Dec 21 2007] X-SpamTest-Info: helo_type=3 X-SpamTest-Info: {received from trusted relay: not dialup} X-SpamTest-Method: none X-SpamTest-Method: Local Lists X-SpamTest-Rate: 0 X-SpamTest-Status: Not detected X-SpamTest-Status-Extended: not_detected X-SpamTest-Version: SMTP-Filter Version 3.0.0 [0255], KAS30/Release Cc: freebsd-net@freebsd.org, freebsd-stable@freebsd.org Subject: Re: Packet loss every 30.999 seconds 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: Sat, 22 Dec 2007 05:37:40 -0000 --soWJpSPh+l8Y6Fy7 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Dec 21, 2007 at 04:24:32PM -0800, Alfred Perlstein wrote: > * David G Lawrence [071221 15:42] wrote: > > > > Unfortunately, the version of the patch that I sent out isn't go= ing to > > > > help your problem. It needs to yield at the top of the loop, but vp= isn't > > > > necessarily valid after the wakeup from the msleep. That's a proble= m that > > > > I'm having trouble figuring out a solution to - the solutions that = come > > > > to mind will all significantly increase the overhead of the loop. > > >=20 > > > I apologize for not reading the code as I am swamped, but a technique > > > that Matt Dillon used for bufs might work here. > > >=20 > > > Can you use a placeholder vnode as a place to restart the scan? > > > you might have to mark it special so that other threads/things > > > (getnewvnode()?) don't molest it, but it can provide for a convenient > > > restart point. > >=20 > > That was one of the solutions that I considered and rejected since it > > would significantly increase the overhead of the loop. > > The solution provided by Kostik Belousov that uses uio_yield looks l= ike > > a find solution. I intend to try it out on some servers RSN. >=20 > Out of curiosity's sake, why would it make the loop slower? one > would only add the placeholder when yielding, not for every iteration. Marker is already reinserted into the list on every iteration. --soWJpSPh+l8Y6Fy7 Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (FreeBSD) iD8DBQFHbKKcC3+MBN1Mb4gRAoT1AKCBmHGiMjE36UzMRadhMvV4puYuSwCfQby3 vGqKmgClkrEd3/x3ytBSUao= =HhMC -----END PGP SIGNATURE----- --soWJpSPh+l8Y6Fy7--