From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt Subject: Re: [PATCH V2 1/2] mm: move FAULT_AROUND_ORDER to arch/ Date: Mon, 07 Apr 2014 15:45:34 +1000 Message-ID: <1396849534.3671.35.camel@pasglop> References: <1396592835-24767-1-git-send-email-maddy@linux.vnet.ibm.com> <1396592835-24767-2-git-send-email-maddy@linux.vnet.ibm.com> <533EDB63.8090909@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <533EDB63.8090909@intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+glppe-linuxppc-embedded-2=m.gmane.org@lists.ozlabs.org Sender: "Linuxppc-dev" To: Dave Hansen Cc: linux-arch@vger.kernel.org, rusty@rustcorp.com.au, Madhavan Srinivasan , riel@redhat.com, x86@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, peterz@infradead.org, ak@linux.intel.com, paulus@samba.org, mgorman@suse.de, akpm@linux-foundation.org, linuxppc-dev@lists.ozlabs.org, mingo@kernel.org, kirill.shutemov@linux.intel.com List-Id: linux-arch.vger.kernel.org T24gRnJpLCAyMDE0LTA0LTA0IGF0IDA5OjE4IC0wNzAwLCBEYXZlIEhhbnNlbiB3cm90ZToKPiBP biAwNC8wMy8yMDE0IDExOjI3IFBNLCBNYWRoYXZhbiBTcmluaXZhc2FuIHdyb3RlOgo+ID4gVGhp cyBwYXRjaCBjcmVhdGVzIGluZnJhc3RydWN0dXJlIHRvIG1vdmUgdGhlIEZBVUxUX0FST1VORF9P UkRFUgo+ID4gdG8gYXJjaC8gdXNpbmcgS2NvbmZpZy4gVGhpcyB3aWxsIGVuYWJsZSBhcmNoaXRl Y3R1cmUgbWFpbnRhaW5lcnMKPiA+IHRvIGRlY2lkZSBvbiBzdWl0YWJsZSBGQVVMVF9BUk9VTkRf T1JERVIgdmFsdWUgYmFzZWQgb24KPiA+IHBlcmZvcm1hbmNlIGRhdGEgZm9yIHRoYXQgYXJjaGl0 ZWN0dXJlLiBQYXRjaCBhbHNvIGFkZHMKPiA+IEZBVUxUX0FST1VORF9PUkRFUiBLY29uZmlnIGVs ZW1lbnQgaW4gYXJjaC9YODYuCj4gCj4gUGxlYXNlIGRvbid0IGRvIGl0IHRoaXMgd2F5Lgo+IAo+ IEluIG1tL0tjb25maWcsIHB1dAo+IAo+IAljb25maWcgRkFVTFRfQVJPVU5EX09SREVSCj4gCQlp bnQKPiAJCWRlZmF1bHQgMTIzNCBpZiBQT1dFUlBDCj4gCQlkZWZhdWx0IDQKPiAKPiBUaGUgd2F5 IHlvdSBoYXZlIGl0IG5vdywgZXZlcnkgc2luZ2xlIGFyY2hpdGVjdHVyZSB0aGF0IG5lZWRzIHRv IGVuYWJsZQo+IHRoaXMgaGFzIHRvIGdvIHB1dCB0aGF0IGluIHRoZWlyIEtjb25maWcuICBUaGF0 J3MgbWFkbmVzcy4gIFRoaXMgd2F5LAo+IHlvdSBvbmx5IHB1dCBpdCBpbiBvbmUgcGxhY2UsIGFu ZCBmb2xrcyBvbmx5IGhhdmUgdG8gY2FyZSBpZiB0aGV5IHdhbnQKPiB0byBjaGFuZ2UgdGhlIGRl ZmF1bHQgdG8gYmUgc29tZXRoaW5nIG90aGVyIHRoYW4gNC4KCkFsc28gZG9lcyBpdCBoYXZlIHRv IGJlIGEgY29uc3RhbnQgPyBNYWRkeSBoZXJlIHRlc3RlZCBvbiBvdXIgUE9XRVIKc2VydmVycy4g VGhlICJTd2VldCBzcG90IiB2YWx1ZSBtaWdodCBiZSBWRVJZIGRpZmZlcmVudCBvbiBhbiBlbWJl ZGRlZApjaGlwIG9yIGV2ZW4gb24gYSBmdXR1cmUgZ2VuZXJhdGlvbiBvZiBzZXJ2ZXIgY2hpcC4K CkNoZWVycywKQmVuLgoKCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fCkxpbnV4cHBjLWRldiBtYWlsaW5nIGxpc3QKTGludXhwcGMtZGV2QGxpc3RzLm96bGFi cy5vcmcKaHR0cHM6Ly9saXN0cy5vemxhYnMub3JnL2xpc3RpbmZvL2xpbnV4cHBjLWRldg== From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org ([63.228.1.57]:42534 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754886AbaDGHGE (ORCPT ); Mon, 7 Apr 2014 03:06:04 -0400 Message-ID: <1396849534.3671.35.camel@pasglop> Subject: Re: [PATCH V2 1/2] mm: move FAULT_AROUND_ORDER to arch/ From: Benjamin Herrenschmidt Date: Mon, 07 Apr 2014 15:45:34 +1000 In-Reply-To: <533EDB63.8090909@intel.com> References: <1396592835-24767-1-git-send-email-maddy@linux.vnet.ibm.com> <1396592835-24767-2-git-send-email-maddy@linux.vnet.ibm.com> <533EDB63.8090909@intel.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Dave Hansen Cc: Madhavan Srinivasan , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, x86@kernel.org, paulus@samba.org, kirill.shutemov@linux.intel.com, rusty@rustcorp.com.au, akpm@linux-foundation.org, riel@redhat.com, mgorman@suse.de, ak@linux.intel.com, peterz@infradead.org, mingo@kernel.org Message-ID: <20140407054534.zuqjl45gtEHkPOl9Mt-90yf-dDsCMXrFR18HVtJ5U7w@z> On Fri, 2014-04-04 at 09:18 -0700, Dave Hansen wrote: > On 04/03/2014 11:27 PM, Madhavan Srinivasan wrote: > > This patch creates infrastructure to move the FAULT_AROUND_ORDER > > to arch/ using Kconfig. This will enable architecture maintainers > > to decide on suitable FAULT_AROUND_ORDER value based on > > performance data for that architecture. Patch also adds > > FAULT_AROUND_ORDER Kconfig element in arch/X86. > > Please don't do it this way. > > In mm/Kconfig, put > > config FAULT_AROUND_ORDER > int > default 1234 if POWERPC > default 4 > > The way you have it now, every single architecture that needs to enable > this has to go put that in their Kconfig. That's madness. This way, > you only put it in one place, and folks only have to care if they want > to change the default to be something other than 4. Also does it have to be a constant ? Maddy here tested on our POWER servers. The "Sweet spot" value might be VERY different on an embedded chip or even on a future generation of server chip. Cheers, Ben.