From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753995Ab1H3XOP (ORCPT ); Tue, 30 Aug 2011 19:14:15 -0400 Received: from rcsinet15.oracle.com ([148.87.113.117]:26647 "EHLO rcsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753422Ab1H3XON convert rfc822-to-8bit (ORCPT ); Tue, 30 Aug 2011 19:14:13 -0400 MIME-Version: 1.0 Message-ID: <4599ff4c-5273-4605-9a61-d26a9a6484fe@default> Date: Tue, 30 Aug 2011 14:51:39 -0700 (PDT) From: Dan Magenheimer To: Valdis.Kletnieks@vt.edu Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, jeremy@goop.org, hughd@google.com, ngupta@vflare.org, Konrad Wilk , JBeulich@novell.com, Kurt Hackel , npiggin@kernel.dk, akpm@linux-foundation.org, riel@redhat.com, hannes@cmpxchg.org, matthew@wil.cx, Chris Mason , sjenning@linux.vnet.ibm.com, kamezawa.hiroyu@jp.fujitsu.com, jackdachef@gmail.com, cyclonusj@gmail.com, levinsasha928@gmail.com Subject: RE: [PATCH V8 4/4] mm: frontswap: config and doc files References: <20110829164949.GA27238@ca-server1.us.oracle.com 19213.1314737185@turing-police.cc.vt.edu> In-Reply-To: <19213.1314737185@turing-police.cc.vt.edu> X-Priority: 3 X-Mailer: Oracle Beehive Extensions for Outlook 2.0.1.4.1.0 (410211) [OL 12.0.6557.5001] Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8BIT X-Source-IP: rtcsinet22.oracle.com [66.248.204.30] X-CT-RefId: str=0001.0A090204.4E5D6E6E.00A2,ss=1,re=0.000,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > From: Valdis.Kletnieks@vt.edu [mailto:Valdis.Kletnieks@vt.edu] > Subject: Re: [PATCH V8 4/4] mm: frontswap: config and doc files > > On Mon, 29 Aug 2011 09:49:49 PDT, Dan Magenheimer said: > > > --- linux/mm/Kconfig 2011-08-08 08:19:26.303686905 -0600 > > +++ frontswap/mm/Kconfig 2011-08-29 09:52:14.308745832 -0600 > > @@ -370,3 +370,20 @@ config CLEANCACHE > > in a negligible performance hit. > > > > If unsure, say Y to enable cleancache > > + > > +config FRONTSWAP > > + bool "Enable frontswap to cache swap pages if tmem is present" > > + depends on SWAP > > + default n > > > + > > + If unsure, say Y to enable frontswap. > > Am I the only guy who gets irked when the "default" doesn't match the > "If unsure" suggestion? :) (and yes, I know we have guidelines for > what the "default" should be...) Hi Valdis -- Thanks for the review! Count me as irked. The default should be "y" because the overhead is extremely tiny when not enabled at runtime by a backend (though admittedly non-zero), but I got flamed by Linus last time I tried that (for cleancache), so I'm not going to try it for frontswap! :-) The "if unsure" is the best I can do for now to encourage distros to enable it. Dan