From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f69.google.com (mail-wm0-f69.google.com [74.125.82.69]) by kanga.kvack.org (Postfix) with ESMTP id A50746B0038 for ; Mon, 13 Mar 2017 06:43:08 -0400 (EDT) Received: by mail-wm0-f69.google.com with SMTP id d66so13233094wmi.2 for ; Mon, 13 Mar 2017 03:43:08 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id n26si10350915wmi.51.2017.03.13.03.43.06 for (version=TLS1 cipher=AES128-SHA bits=128/128); Mon, 13 Mar 2017 03:43:07 -0700 (PDT) Date: Mon, 13 Mar 2017 11:43:02 +0100 From: Michal Hocko Subject: Re: WTH is going on with memory hotplug sysf interface (was: Re: [RFC PATCH] mm, hotplug: get rid of auto_online_blocks) Message-ID: <20170313104302.GK31518@dhcp22.suse.cz> References: <1488462828-174523-1-git-send-email-imammedo@redhat.com> <20170302142816.GK1404@dhcp22.suse.cz> <20170302180315.78975d4b@nial.brq.redhat.com> <20170303082723.GB31499@dhcp22.suse.cz> <20170303183422.6358ee8f@nial.brq.redhat.com> <20170306145417.GG27953@dhcp22.suse.cz> <20170307134004.58343e14@nial.brq.redhat.com> <20170309125400.GI11592@dhcp22.suse.cz> <20170310135807.GI3753@dhcp22.suse.cz> <20170313113110.6a9636a1@nial.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170313113110.6a9636a1@nial.brq.redhat.com> Sender: owner-linux-mm@kvack.org List-ID: To: Igor Mammedov Cc: Heiko Carstens , Vitaly Kuznetsov , linux-mm@kvack.org, Andrew Morton , Greg KH , "K. Y. Srinivasan" , David Rientjes , Daniel Kiper , linux-api@vger.kernel.org, LKML , linux-s390@vger.kernel.org, xen-devel@lists.xenproject.org, linux-acpi@vger.kernel.org, qiuxishi@huawei.com, toshi.kani@hpe.com, xieyisheng1@huawei.com, slaoub@gmail.com, iamjoonsoo.kim@lge.com, vbabka@suse.cz, Zhang Zhen , Reza Arbab , Yasuaki Ishimatsu , Tang Chen On Mon 13-03-17 11:31:10, Igor Mammedov wrote: > On Fri, 10 Mar 2017 14:58:07 +0100 [...] > > [ 0.000000] ACPI: SRAT: Node 0 PXM 0 [mem 0x00000000-0x0009ffff] > > [ 0.000000] ACPI: SRAT: Node 0 PXM 0 [mem 0x00100000-0x3fffffff] > > [ 0.000000] ACPI: SRAT: Node 1 PXM 1 [mem 0x40000000-0x7fffffff] > > [ 0.000000] ACPI: SRAT: Node 0 PXM 0 [mem 0x100000000-0x27fffffff] hotplug > > [ 0.000000] NUMA: Node 0 [mem 0x00000000-0x0009ffff] + [mem 0x00100000-0x3fffffff] -> [mem 0x00000000-0x3fffffff] > > [ 0.000000] NODE_DATA(0) allocated [mem 0x3fffc000-0x3fffffff] > > [ 0.000000] NODE_DATA(1) allocated [mem 0x7ffdc000-0x7ffdffff] > > [ 0.000000] Zone ranges: > > [ 0.000000] DMA [mem 0x0000000000001000-0x0000000000ffffff] > > [ 0.000000] DMA32 [mem 0x0000000001000000-0x000000007ffdffff] > > [ 0.000000] Normal empty > > [ 0.000000] Movable zone start for each node > > [ 0.000000] Early memory node ranges > > [ 0.000000] node 0: [mem 0x0000000000001000-0x000000000009efff] > > [ 0.000000] node 0: [mem 0x0000000000100000-0x000000003fffffff] > > [ 0.000000] node 1: [mem 0x0000000040000000-0x000000007ffdffff] > > > > so there is neither any normal zone nor movable one at the boot time. > it could be if hotpluggable memory were present at boot time in E802 table > (if I remember right when running on hyperv there is movable zone at boot time), > > but in qemu hotpluggable memory isn't put into E820, > so zone is allocated later when memory is enumerated > by ACPI subsystem and onlined. > It causes less issues wrt movable zone and works for > different versions of linux/windows as well. > > That's where in kernel auto-onlining could be also useful, > since user would be able to start-up with with small > non removable memory plus several removable DIMMs > and have all the memory onlined/available by the time > initrd is loaded. (missing piece here is onling > removable memory as movable by default). Why we should even care to online that memory that early rather than making it available via e820? > > Then I hotplugged 1G slot > > (qemu) object_add memory-backend-ram,id=mem1,size=1G > > (qemu) device_add pc-dimm,id=dimm1,memdev=mem1 > You can also specify node a pc-dimm goes to with 'node' property > if it should go to other then node 0. > > device_add pc-dimm,id=dimm1,memdev=mem1,node=1 thanks for the tip > > unfortunatelly the memory didn't show up automatically and I got > > [ 116.375781] acpi PNP0C80:00: Enumeration failure > it should work, > do you have CONFIG_ACPI_HOTPLUG_MEMORY enabled? No I didn't. Thanks, good to know! -- 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