Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266115AbUIESmH (ORCPT ); Sun, 5 Sep 2004 14:42:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266901AbUIESmH (ORCPT ); Sun, 5 Sep 2004 14:42:07 -0400 Received: from mx1.redhat.com ([66.187.233.31]:41164 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S266115AbUIESmC (ORCPT ); Sun, 5 Sep 2004 14:42:02 -0400 Date: Sun, 5 Sep 2004 20:41:46 +0200 From: Arjan van de Ven To: Linus Torvalds Cc: Nick Piggin , "David S. Miller" , akpm@osdl.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [RFC][PATCH 0/3] beat kswapd with the proverbial clue-bat Message-ID: <20040905184146.GA6849@devserv.devel.redhat.com> References: <413AA7B2.4000907@yahoo.com.au> <20040904230210.03fe3c11.davem@davemloft.net> <413AAF49.5070600@yahoo.com.au> <413AE6E7.5070103@yahoo.com.au> <1094405830.2809.8.camel@laptop.fenrus.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="UlVJffcvxoiEqYs2" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1568 Lines: 47 --UlVJffcvxoiEqYs2 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Sun, Sep 05, 2004 at 10:58:07AM -0700, Linus Torvalds wrote: > > > On Sun, 5 Sep 2004, Arjan van de Ven wrote: > > > > well... we have a reverse mapping now. What is stopping us from doing > > physical defragmentation ? > > Nothing but replacement policy, really, and the fact that not everything > is rmappable. > > I think we should _normally_ honor replacement policy, the way we do now. yes it absolutely is quite a heavy hammer. However right now the alternative (free a LOT of memory and hope it collapses into higher order ones) is even heavier, freeing the wrong 8 pages is less of a disturbance than freeing 8000 of the mostly wrong pages ;) I absolutely agree this heavy hammer only should trigger if there is a request for a higher order page that isn't there. Doing it from a special thread does make sense, makes it relatively easy to keep track of such wakeups and more importantly rate limit them etc. --UlVJffcvxoiEqYs2 Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.1 (GNU/Linux) iD8DBQFBO13qxULwo51rQBIRAh29AJ9G+qbI1kjC+mlEAT/Puc1a6fBTXACeMEaB 6PTpaCS/kHTID9QBijMFhZM= =aGN8 -----END PGP SIGNATURE----- --UlVJffcvxoiEqYs2-- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/