From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f200.google.com (mail-qk0-f200.google.com [209.85.220.200]) by kanga.kvack.org (Postfix) with ESMTP id B37296B407A for ; Mon, 27 Aug 2018 08:31:38 -0400 (EDT) Received: by mail-qk0-f200.google.com with SMTP id u129-v6so14821415qkf.15 for ; Mon, 27 Aug 2018 05:31:38 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id l34-v6sor7941158qkh.42.2018.08.27.05.31.37 for (Google Transport Security); Mon, 27 Aug 2018 05:31:37 -0700 (PDT) Subject: Re: [PATCH 1/2] Revert "x86/e820: put !E820_TYPE_RAM regions into memblock.reserved" References: <20180823182513.8801-1-msys.mizuma@gmail.com> <20180824000325.GA20143@hori1.linux.bs1.fc.nec.co.jp> <20180824082908.GC29735@dhcp22.suse.cz> From: Masayoshi Mizuma Message-ID: Date: Mon, 27 Aug 2018 08:31:35 -0400 MIME-Version: 1.0 In-Reply-To: <20180824082908.GC29735@dhcp22.suse.cz> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: mhocko@kernel.org, n-horiguchi@ah.jp.nec.com, Pavel.Tatashin@microsoft.com Cc: linux-mm@kvack.org, m.mizuma@jp.fujitsu.com, linux-kernel@vger.kernel.org, x86@kernel.org, osalvador@techadventures.net Hi Pavel, I would appreciate if you could send the feedback for the patch. Thanks! Masa On 08/24/2018 04:29 AM, Michal Hocko wrote: > On Fri 24-08-18 00:03:25, Naoya Horiguchi wrote: >> (CCed related people) > > Fixup Pavel email. > >> >> Hi Mizuma-san, >> >> Thank you for the report. >> The mentioned patch was created based on feedbacks from reviewers/maintainers, >> so I'd like to hear from them about how we should handle the issue. >> >> And one note is that there is a follow-up patch for "x86/e820: put !E820_TYPE_RAM >> regions into memblock.reserved" which might be affected by your changes. >> >>> commit e181ae0c5db9544de9c53239eb22bc012ce75033 >>> Author: Pavel Tatashin >>> Date: Sat Jul 14 09:15:07 2018 -0400 >>> >>> mm: zero unavailable pages before memmap init >> >> Thanks, >> Naoya Horiguchi >> >> On Thu, Aug 23, 2018 at 02:25:12PM -0400, Masayoshi Mizuma wrote: >>> From: Masayoshi Mizuma >>> >>> commit 124049decbb1 ("x86/e820: put !E820_TYPE_RAM regions into >>> memblock.reserved") breaks movable_node kernel option because it >>> changed the memory gap range to reserved memblock. So, the node >>> is marked as Normal zone even if the SRAT has Hot plaggable affinity. >>> >>> ===================================================================== >>> kernel: BIOS-e820: [mem 0x0000180000000000-0x0000180fffffffff] usable >>> kernel: BIOS-e820: [mem 0x00001c0000000000-0x00001c0fffffffff] usable >>> ... >>> kernel: reserved[0x12]#011[0x0000181000000000-0x00001bffffffffff], 0x000003f000000000 bytes flags: 0x0 >>> ... >>> kernel: ACPI: SRAT: Node 2 PXM 6 [mem 0x180000000000-0x1bffffffffff] hotplug >>> kernel: ACPI: SRAT: Node 3 PXM 7 [mem 0x1c0000000000-0x1fffffffffff] hotplug >>> ... >>> kernel: Movable zone start for each node >>> kernel: Node 3: 0x00001c0000000000 >>> kernel: Early memory node ranges >>> ... >>> ===================================================================== >>> >>> Naoya's v1 patch [*] fixes the original issue and this movable_node >>> issue doesn't occur. >>> Let's revert commit 124049decbb1 ("x86/e820: put !E820_TYPE_RAM >>> regions into memblock.reserved") and apply the v1 patch. >>> >>> [*] https://lkml.org/lkml/2018/6/13/27 >>> >>> Signed-off-by: Masayoshi Mizuma >>> --- >>> arch/x86/kernel/e820.c | 15 +++------------ >>> 1 file changed, 3 insertions(+), 12 deletions(-) >>> >>> diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c >>> index c88c23c658c1..d1f25c831447 100644 >>> --- a/arch/x86/kernel/e820.c >>> +++ b/arch/x86/kernel/e820.c >>> @@ -1248,7 +1248,6 @@ void __init e820__memblock_setup(void) >>> { >>> int i; >>> u64 end; >>> - u64 addr = 0; >>> >>> /* >>> * The bootstrap memblock region count maximum is 128 entries >>> @@ -1265,21 +1264,13 @@ void __init e820__memblock_setup(void) >>> struct e820_entry *entry = &e820_table->entries[i]; >>> >>> end = entry->addr + entry->size; >>> - if (addr < entry->addr) >>> - memblock_reserve(addr, entry->addr - addr); >>> - addr = end; >>> if (end != (resource_size_t)end) >>> continue; >>> >>> - /* >>> - * all !E820_TYPE_RAM ranges (including gap ranges) are put >>> - * into memblock.reserved to make sure that struct pages in >>> - * such regions are not left uninitialized after bootup. >>> - */ >>> if (entry->type != E820_TYPE_RAM && entry->type != E820_TYPE_RESERVED_KERN) >>> - memblock_reserve(entry->addr, entry->size); >>> - else >>> - memblock_add(entry->addr, entry->size); >>> + continue; >>> + >>> + memblock_add(entry->addr, entry->size); >>> } >>> >>> /* Throw away partial pages: */ >>> -- >>> 2.18.0 >>> >>> >