From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753387AbbIJHyU (ORCPT ); Thu, 10 Sep 2015 03:54:20 -0400 Received: from metis.ext.pengutronix.de ([92.198.50.35]:44427 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751491AbbIJHyQ (ORCPT ); Thu, 10 Sep 2015 03:54:16 -0400 Date: Thu, 10 Sep 2015 09:53:41 +0200 From: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= To: Russell King - ARM Linux Cc: Maxime Coquelin , Arnd Bergmann , olof@lixom.net, khilman@kernel.org, afaerber@suse.de, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/3] ARM: Make FORCE_MAX_ZONEORDER configurable if ARM_SINGLE_ARMV7M Message-ID: <20150910075340.GJ14598@pengutronix.de> References: <1441744686-20521-1-git-send-email-mcoquelin.stm32@gmail.com> <1441744686-20521-2-git-send-email-mcoquelin.stm32@gmail.com> <20150908221912.GE21084@n2100.arm.linux.org.uk> <20150909054125.GA14598@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20150909054125.GA14598@pengutronix.de> User-Agent: Mutt/1.5.21 (2010-09-15) X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c0 X-SA-Exim-Mail-From: ukl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 09, 2015 at 07:41:25AM +0200, Uwe Kleine-König wrote: > On Tue, Sep 08, 2015 at 11:19:13PM +0100, Russell King - ARM Linux wrote: > > On Tue, Sep 08, 2015 at 10:38:04PM +0200, Maxime Coquelin wrote: > > > This patch makes FORCE_MAX_ZONEORDER configurable in defconfig for ARMV7-M > > > when built for a single platform. > > > > I'd prefer if we didn't do this, because this isn't supposed to be a user > > visible "option". It's an option that was introduced to avoid having to > > throw masses of #ifdefs into the definition of MAX_ZONEORDER. > > > > The problem with it is that it's a "well, what do I set this to?" option > > and that leads to "oh, I'll just choose the default because I don't know > > any better". > > > > Do we know why EFM32 needs a value of 9 here? It's not documented in > > the original commit, and it really _should_ have been. > IIRC it was done because of memory pressure. But not sure this makes any > sense. I will try with the default value later today and report back. I updated my patch stack to 4.2 and the difference between 9 and 11 is: Using 9: / # free total used free shared buffers Mem: 3744 1688 2056 0 0 -/+ buffers: 1688 2056 vs. using 11: / # free total used free shared buffers Mem: 3744 1696 2048 0 0 -/+ buffers: 1696 2048 so it works with bearable costs. If you want to get rid of the special casing for efm32 that's fine for me. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ |