From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx145.postini.com [74.125.245.145]) by kanga.kvack.org (Postfix) with SMTP id 8B0566B0031 for ; Thu, 25 Jul 2013 18:37:01 -0400 (EDT) Message-ID: <1374791763.16322.237.camel@misato.fc.hp.com> Subject: Re: [PATCH v2] mm/hotplug, x86: Disable ARCH_MEMORY_PROBE by default From: Toshi Kani Date: Thu, 25 Jul 2013 16:36:03 -0600 In-Reply-To: <20130725213822.GG18254@gmail.com> References: <1374256068-26016-1-git-send-email-toshi.kani@hp.com> <20130722083721.GC25976@gmail.com> <1374513120.16322.21.camel@misato.fc.hp.com> <20130723080101.GB15255@gmail.com> <1374612301.16322.136.camel@misato.fc.hp.com> <20130724042041.GA8504@gmail.com> <1374685121.16322.218.camel@misato.fc.hp.com> <20130725213822.GG18254@gmail.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Ingo Molnar Cc: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, x86@kernel.org, dave@sr71.net, kosaki.motohiro@gmail.com, isimatu.yasuaki@jp.fujitsu.com, tangchen@cn.fujitsu.com, vasilis.liaskovitis@profitbricks.com On Thu, 2013-07-25 at 23:38 +0200, Ingo Molnar wrote: > * Toshi Kani wrote: > > > > You claimed that the only purpose of this on x86 was > > > that testing was done on non-hotplug systems, using > > > this interface. Non-hotplug systems have e820 maps. > > > > Right. Sorry, I first thought that the interface needed > > to work as defined, i.e. detect a new memory. But for > > the test purpose on non-hotplug systems, that is not > > necessary. So, I agree that we can check e820. > > > > I summarized two options in the email below. > > https://lkml.org/lkml/2013/7/23/602 > > > > Option 1) adds a check with e820. Option 2) deprecates > > the interface by removing the config option from x86 > > Kconfig. I was thinking that we could evaluate two > > options after this patch gets in. Does it make sense? > > Yeah. > > That having said, if the e820 check is too difficult to > pull off straight away, I also don't mind keeping it as-is > if it's useful for testing. Just make sure you document it > as "you need to be careful with this" (beyond it being a > root-only interface to begin with). Sounds good. I will keep it as-is for now, and add more clarification to the document. I will send an updated patch shortly. I will make sure to come back after this patch gets in and we get more info about users. Thanks, -Toshi -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org