From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx141.postini.com [74.125.245.141]) by kanga.kvack.org (Postfix) with SMTP id 2CE7D6B0036 for ; Thu, 22 Aug 2013 16:22:05 -0400 (EDT) Received: by mail-qe0-f47.google.com with SMTP id b4so1403885qen.20 for ; Thu, 22 Aug 2013 13:22:04 -0700 (PDT) Date: Thu, 22 Aug 2013 16:21:58 -0400 From: Tejun Heo Subject: Re: [PATCH 0/8] x86, acpi: Move acpi_initrd_override() earlier. Message-ID: <20130822202158.GD3490@mtj.dyndns.org> References: <20130821153639.GA17432@htj.dyndns.org> <1377113503.10300.492.camel@misato.fc.hp.com> <20130821195410.GA2436@htj.dyndns.org> <1377116968.10300.514.camel@misato.fc.hp.com> <20130821204041.GC2436@htj.dyndns.org> <1377124595.10300.594.camel@misato.fc.hp.com> <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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1377202292.10300.693.camel@misato.fc.hp.com> Sender: owner-linux-mm@kvack.org List-ID: To: Toshi Kani Cc: Zhang Yanfei , 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 Hello, On Thu, Aug 22, 2013 at 02:11:32PM -0600, Toshi Kani wrote: > It's too late for the kernel image itself, but it prevents allocating > kernel memory from movable ranges after that. I'd say it solves a half > of the issue this time. That works if such half solution eventually leads to the full solution. This is just a distraction. You are already too late in the boot sequence. It doesn't even qualify as a half solution. It's like obsessing about a speck on your shirt without your trousers on. If you want to solve this, do that from a place where it actually is solvable. > > > Also, how do you support local page tables without pursing SRAT early? > > > > Does it even matter with huge mappings? It's gonna be contained in a > > single page anyway, right? > > Are the huge mappings always used? We cannot force user programs to use > huge pages, can we? Everything is a trade-off. Should we do all this just to support the off chance someone tries to use memory hotplug on a machine which doesn't support huge mapping when virtually all CPUs on market supports it? > As for the maintainability, I am far more concerned with your suggestion > of having a separate page table init code when SRAT is used. This kind > of divergence is a recipe of breakage. I don't buy that. The only thing which needs to change is the directionality of allocation and we probably don't even need to do that if huge mapping is in use. Thanks. -- tejun -- 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