From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f176.google.com (mail-pf0-f176.google.com [209.85.192.176]) by kanga.kvack.org (Postfix) with ESMTP id AB6426B007E for ; Thu, 7 Apr 2016 10:21:55 -0400 (EDT) Received: by mail-pf0-f176.google.com with SMTP id 184so56883817pff.0 for ; Thu, 07 Apr 2016 07:21:55 -0700 (PDT) Received: from foss.arm.com (foss.arm.com. [217.140.101.70]) by mx.google.com with ESMTP id m27si379011pfj.88.2016.04.07.07.21.54 for ; Thu, 07 Apr 2016 07:21:54 -0700 (PDT) Date: Thu, 7 Apr 2016 15:21:48 +0100 From: Will Deacon Subject: Re: [PATCH 1/2] arm64: mem-model: add flatmem model for arm64 Message-ID: <20160407142148.GI5657@arm.com> References: <1459844572-53069-1-git-send-email-puck.chen@hisilicon.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1459844572-53069-1-git-send-email-puck.chen@hisilicon.com> Sender: owner-linux-mm@kvack.org List-ID: To: Chen Feng Cc: catalin.marinas@arm.com, ard.biesheuvel@linaro.org, mark.rutland@arm.com, akpm@linux-foundation.org, robin.murphy@arm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, mhocko@suse.com, kirill.shutemov@linux.intel.com, rientjes@google.com, linux-mm@kvack.org, puck.chen@foxmail.com, oliver.fu@hisilicon.com, linuxarm@huawei.com, dan.zhao@hisilicon.com, suzhuangluan@hisilicon.com, yudongbin@hislicon.com, albert.lubing@hisilicon.com, xuyiping@hisilicon.com, saberlily.xia@hisilicon.com On Tue, Apr 05, 2016 at 04:22:51PM +0800, Chen Feng wrote: > We can reduce the memory allocated at mem-map > by flatmem. > > currently, the default memory-model in arm64 is > sparse memory. The mem-map array is not freed in > this scene. If the physical address is too long, > it will reserved too much memory for the mem-map > array. Can you elaborate a bit more on this, please? We use the vmemmap, so any spaces between memory banks only burns up virtual space. What exactly is the problem you're seeing that makes you want to use flatmem (which is probably unsuitable for the majority of arm64 machines). Will -- 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