From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f198.google.com (mail-wr0-f198.google.com [209.85.128.198]) by kanga.kvack.org (Postfix) with ESMTP id 19C816B04EF for ; Wed, 9 May 2018 07:47:17 -0400 (EDT) Received: by mail-wr0-f198.google.com with SMTP id p1-v6so23449978wrm.7 for ; Wed, 09 May 2018 04:47:17 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id k50-v6si1001131edb.231.2018.05.09.04.47.15 for (version=TLS1 cipher=AES128-SHA bits=128/128); Wed, 09 May 2018 04:47:15 -0700 (PDT) Date: Wed, 9 May 2018 13:47:12 +0200 From: Michal Hocko Subject: Re: [External] [RFC PATCH v1 3/6] mm, zone_type: create ZONE_NVM and fill into GFP_ZONE_TABLE Message-ID: <20180509114712.GP32366@dhcp22.suse.cz> References: <1525746628-114136-1-git-send-email-yehs1@lenovo.com> <1525746628-114136-4-git-send-email-yehs1@lenovo.com> 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: Huaisheng HS1 Ye Cc: Randy Dunlap , "akpm@linux-foundation.org" , "linux-mm@kvack.org" , "willy@infradead.org" , "vbabka@suse.cz" , "mgorman@techsingularity.net" , "pasha.tatashin@oracle.com" , "alexander.levin@verizon.com" , "hannes@cmpxchg.org" , "penguin-kernel@I-love.SAKURA.ne.jp" , "colyli@suse.de" , NingTing Cheng , Ocean HY1 He , "linux-kernel@vger.kernel.org" , "linux-nvdimm@lists.01.org" On Wed 09-05-18 04:22:10, Huaisheng HS1 Ye wrote: > > > On 05/07/2018 07:33 PM, Huaisheng HS1 Ye wrote: > > > diff --git a/mm/Kconfig b/mm/Kconfig > > > index c782e8f..5fe1f63 100644 > > > --- a/mm/Kconfig > > > +++ b/mm/Kconfig > > > @@ -687,6 +687,22 @@ config ZONE_DEVICE > > > > > > +config ZONE_NVM > > > + bool "Manage NVDIMM (pmem) by memory management (EXPERIMENTAL)" > > > + depends on NUMA && X86_64 > > > > Hi, > > I'm curious why this depends on NUMA. Couldn't it be useful in non-NUMA > > (i.e., UMA) configs? > > > I wrote these patches with two sockets testing platform, and there are two DDRs and two NVDIMMs have been installed to it. > So, for every socket it has one DDR and one NVDIMM with it. Here is memory region from memblock, you can get its distribution. > > 435 [ 0.000000] Zone ranges: > 436 [ 0.000000] DMA [mem 0x0000000000001000-0x0000000000ffffff] > 437 [ 0.000000] DMA32 [mem 0x0000000001000000-0x00000000ffffffff] > 438 [ 0.000000] Normal [mem 0x0000000100000000-0x00000046bfffffff] > 439 [ 0.000000] NVM [mem 0x0000000440000000-0x00000046bfffffff] > 440 [ 0.000000] Device empty > 441 [ 0.000000] Movable zone start for each node > 442 [ 0.000000] Early memory node ranges > 443 [ 0.000000] node 0: [mem 0x0000000000001000-0x000000000009ffff] > 444 [ 0.000000] node 0: [mem 0x0000000000100000-0x00000000a69c2fff] > 445 [ 0.000000] node 0: [mem 0x00000000a7654000-0x00000000a85eefff] > 446 [ 0.000000] node 0: [mem 0x00000000ab399000-0x00000000af3f6fff] > 447 [ 0.000000] node 0: [mem 0x00000000af429000-0x00000000af7fffff] > 448 [ 0.000000] node 0: [mem 0x0000000100000000-0x000000043fffffff] Normal 0 > 449 [ 0.000000] node 0: [mem 0x0000000440000000-0x000000237fffffff] NVDIMM 0 > 450 [ 0.000000] node 1: [mem 0x0000002380000000-0x000000277fffffff] Normal 1 > 451 [ 0.000000] node 1: [mem 0x0000002780000000-0x00000046bfffffff] NVDIMM 1 > > If we disable NUMA, there is a result as Normal an NVDIMM zones will be overlapping with each other. > Current mm treats all memory regions equally, it divides zones just by size, like 16M for DMA, 4G for DMA32, and others above for Normal. > The spanned range of all zones couldn't be overlapped. No, this is not correct. Zones can overlap. -- Michal Hocko SUSE Labs