From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lb0-f199.google.com (mail-lb0-f199.google.com [209.85.217.199]) by kanga.kvack.org (Postfix) with ESMTP id EF7306B0253 for ; Mon, 23 May 2016 03:32:01 -0400 (EDT) Received: by mail-lb0-f199.google.com with SMTP id q17so8079868lbn.3 for ; Mon, 23 May 2016 00:32:01 -0700 (PDT) Received: from mail-wm0-f68.google.com (mail-wm0-f68.google.com. [74.125.82.68]) by mx.google.com with ESMTPS id w202si14222681wmd.67.2016.05.23.00.32.00 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 23 May 2016 00:32:00 -0700 (PDT) Received: by mail-wm0-f68.google.com with SMTP id 67so12284443wmg.0 for ; Mon, 23 May 2016 00:32:00 -0700 (PDT) Date: Mon, 23 May 2016 09:31:58 +0200 From: Michal Hocko Subject: Re: [v2 PATCH] mm: move page_ext_init after all struct pages are initialized Message-ID: <20160523073157.GD2278@dhcp22.suse.cz> References: <1463696006-31360-1-git-send-email-yang.shi@linaro.org> <20160520131649.GC5197@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: "Shi, Yang" Cc: akpm@linux-foundation.org, iamjoonsoo.kim@lge.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linaro-kernel@lists.linaro.org On Fri 20-05-16 08:41:09, Shi, Yang wrote: > On 5/20/2016 6:16 AM, Michal Hocko wrote: > > On Thu 19-05-16 15:13:26, Yang Shi wrote: > > [...] > > > diff --git a/init/main.c b/init/main.c > > > index b3c6e36..2075faf 100644 > > > --- a/init/main.c > > > +++ b/init/main.c > > > @@ -606,7 +606,6 @@ asmlinkage __visible void __init start_kernel(void) > > > initrd_start = 0; > > > } > > > #endif > > > - page_ext_init(); > > > debug_objects_mem_init(); > > > kmemleak_init(); > > > setup_per_cpu_pageset(); > > > @@ -1004,6 +1003,8 @@ static noinline void __init kernel_init_freeable(void) > > > sched_init_smp(); > > > > > > page_alloc_init_late(); > > > + /* Initialize page ext after all struct pages are initializaed */ > > > + page_ext_init(); > > > > > > do_basic_setup(); > > > > I might be missing something but don't we have the same problem with > > CONFIG_FLATMEM? page_ext_init_flatmem is called way earlier. Or > > CONFIG_DEFERRED_STRUCT_PAGE_INIT is never enabled for CONFIG_FLATMEM? > > Yes, CONFIG_DEFERRED_STRUCT_PAGE_INIT depends on MEMORY_HOTPLUG which > depends on SPARSEMEM. So, this config is not valid for FLATMEM at all. Well config MEMORY_HOTPLUG bool "Allow for memory hot-add" depends on SPARSEMEM || X86_64_ACPI_NUMA depends on ARCH_ENABLE_MEMORY_HOTPLUG I wasn't really sure about X86_64_ACPI_NUMA dependency branch which depends on X86_64 && NUMA && ACPI && PCI and that didn't sound like SPARSEMEM only. If the FLATMEM shouldn't exist with CONFIG_DEFERRED_STRUCT_PAGE_INIT can we make that explicit please? -- Michal Hocko SUSE Labs -- 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