From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx193.postini.com [74.125.245.193]) by kanga.kvack.org (Postfix) with SMTP id 1B68E6B0032 for ; Fri, 23 Aug 2013 13:30:32 -0400 (EDT) Received: by mail-pb0-f42.google.com with SMTP id un15so933766pbc.1 for ; Fri, 23 Aug 2013 10:30:31 -0700 (PDT) Message-ID: <52179C14.20407@gmail.com> Date: Sat, 24 Aug 2013 01:29:56 +0800 From: Zhang Yanfei MIME-Version: 1.0 Subject: Re: [PATCH 0/8] x86, acpi: Move acpi_initrd_override() earlier. References: <20130822033234.GA2413@htj.dyndns.org> <1377186729.10300.643.camel@misato.fc.hp.com> <20130822183130.GA3490@mtj.dyndns.org> <1377202292.10300.693.camel@misato.fc.hp.com> <20130822202158.GD3490@mtj.dyndns.org> <1377205598.10300.715.camel@misato.fc.hp.com> <20130822212111.GF3490@mtj.dyndns.org> <1377209861.10300.756.camel@misato.fc.hp.com> <20130823130440.GC10322@mtj.dyndns.org> <1377274448.10300.777.camel@misato.fc.hp.com> <20130823162444.GL3277@htj.dyndns.org> <1377278016.10300.814.camel@misato.fc.hp.com> In-Reply-To: <1377278016.10300.814.camel@misato.fc.hp.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Toshi Kani Cc: Tejun Heo , Tang Chen , konrad.wilk@oracle.com, robert.moore@intel.com, lv.zheng@intel.com, rjw@sisk.pl, lenb@kernel.org, tglx@linutronix.de, mingo@elte.hu, hpa@zytor.com, akpm@linux-foundation.org, trenn@suse.de, yinghai@kernel.org, jiang.liu@huawei.com, wency@cn.fujitsu.com, laijs@cn.fujitsu.com, isimatu.yasuaki@jp.fujitsu.com, izumi.taku@jp.fujitsu.com, mgorman@suse.de, minchan@kernel.org, mina86@mina86.com, gong.chen@linux.intel.com, vasilis.liaskovitis@profitbricks.com, lwoodman@redhat.com, riel@redhat.com, jweiner@redhat.com, prarit@redhat.com, zhangyanfei@cn.fujitsu.com, yanghy@cn.fujitsu.com, x86@kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-acpi@vger.kernel.org Hi Toshi, On 08/24/2013 01:13 AM, Toshi Kani wrote: > Hello, > > On Fri, 2013-08-23 at 12:24 -0400, Tejun Heo wrote: >> On Fri, Aug 23, 2013 at 10:14:08AM -0600, Toshi Kani wrote: >>> I still think acpi table info should be available earlier, but I do not >>> think I can convince you on this. This can be religious debate. >> >> I'm curious. If there aren't substantial enough benefits, why would >> you still want to pull it earlier when it brings in things like initrd >> override and crafting the code carefully so that it's safe to execute >> it from different address modes and so on? Please note that x86 is >> not ia64. The early environment is completely different not only >> technically but also in its diversity and suckiness. It wasn't too >> long ago that vendors were screwing up ACPI left and right. It has >> been getting better but there's a reason why, for example, we still >> consider e820 to be the authoritative information over ACPI. > > Firmware generates tables, and provides them via some interface. Memory > map table can be provided via e820 or EFI memory map. Memory topology > table is provided via ACPI. I agree to prioritize one table over the > other when there is overlap. But in the end, it is the firmware that > generates the tables. Because it is provided via ACPI does not make it > suddenly unreliable. I think table info from e820/EFI/ACPI should be > available at the same time. To me, it makes more sense to use the > hotplug info to initialize memblock than try to find a way to workaround > without it. Yeah, agreed. But sigh.... on x86, we have ACPI initrd override, so we still cannot convince Tj.... I think we will continue to be in that way to find a > workaround in this direction. > > I came from ia64 background, and am not very familiar with x86. So, you > may be very right about that x86 is different. I also agree that initrd > is making it unnecessarily complicated. We may see some initial issues, > but my hope is that the code gets matured over the time. > > Thanks, > -Toshi > -- Thanks. Zhang Yanfei -- 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