From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261255AbULTIU0 (ORCPT ); Mon, 20 Dec 2004 03:20:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261253AbULTIT6 (ORCPT ); Mon, 20 Dec 2004 03:19:58 -0500 Received: from mail20.syd.optusnet.com.au ([211.29.132.201]:57790 "EHLO mail20.syd.optusnet.com.au") by vger.kernel.org with ESMTP id S261255AbULTIEj (ORCPT ); Mon, 20 Dec 2004 03:04:39 -0500 Message-ID: <41C6876D.7070702@kolivas.org> Date: Mon, 20 Dec 2004 19:03:57 +1100 From: Con Kolivas User-Agent: Mozilla Thunderbird 1.0 (X11/20041206) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Nick Piggin Cc: Andrew Morton , lista4@comhem.se, linux-kernel@vger.kernel.org, mr@ramendik.ru, riel@redhat.com Subject: Re: 2.6.10-rc3: kswapd eats CPU on start of memory-eating task References: <1329986.1103525472726.JavaMail.tomcat@pne-ps1-sn1> <20041219231250.457deb12.akpm@osdl.org> <41C682F1.20200@yahoo.com.au> In-Reply-To: <41C682F1.20200@yahoo.com.au> X-Enigmail-Version: 0.89.5.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigA4CCC2E989C6B9A72BA1321B" Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigA4CCC2E989C6B9A72BA1321B Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Nick Piggin wrote: > Andrew Morton wrote: > >> Voluspa wrote: >> >>> Would be nice though if someone else could verify... >> >> >> >> Well I'd love to, but afaik the only workloads which we currently know of >> involve complex userspace apps which I have no experience running. >> >> Did anyone come up with a simple step-by-step procedure for >> reproducing the >> problem? It would be good if someone could do this, because I don't >> think >> we understand the root cause yet? >> > > I admit to generally being in the same boat as you with respect to > running complex userspace apps. > > However, based on this and other scattered reports, I'd say it seems > quite likely that token based thrashing control is the culprit. Based > on the cost/benefit, I wonder if we should disable TBTC by default for > 2.6.10, rather than trying to fix it, and try again for 2.6.11? > > Rik? Andrew? > > Also, it would be nice to have a sysctl to *completely* disable TBTC, > that would make testing easier. Logistically what makes sense is if a timeout of 0 is used as a test that completely disables it (avoids another sysctl too). In time for 2.6.10 we should disable it by default until the regressions are better understood. Tuning it into a useful "on" position can happen later and I suspect requires more code. Con --------------enigA4CCC2E989C6B9A72BA1321B Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.6 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFBxoduZUg7+tp6mRURAmP4AJ9Pk6TDrMxvME80ovsSsnQZzgzu1gCfTaRE AfJS1OG61InPZi5WyMPZp+g= =6Twx -----END PGP SIGNATURE----- --------------enigA4CCC2E989C6B9A72BA1321B--