From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DC429C43331 for ; Thu, 2 Apr 2020 06:12:56 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 9C23620784 for ; Thu, 2 Apr 2020 06:12:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ddxqOfNn" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9C23620784 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 234558E000A; Thu, 2 Apr 2020 02:12:56 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1E5F18E0008; Thu, 2 Apr 2020 02:12:56 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0D3D68E000A; Thu, 2 Apr 2020 02:12:56 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0244.hostedemail.com [216.40.44.244]) by kanga.kvack.org (Postfix) with ESMTP id E75D18E0008 for ; Thu, 2 Apr 2020 02:12:55 -0400 (EDT) Received: from smtpin03.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id AFAA58248047 for ; Thu, 2 Apr 2020 06:12:55 +0000 (UTC) X-FDA: 76661896710.03.star57_8dec2194f4f5b X-HE-Tag: star57_8dec2194f4f5b X-Filterd-Recvd-Size: 5220 Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [207.211.31.120]) by imf01.hostedemail.com (Postfix) with ESMTP for ; Thu, 2 Apr 2020 06:12:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1585807974; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=x6Gi9bGYalknJS+AupiAxMnXVddmoL5l4UamHoetl7M=; b=ddxqOfNneKklDy9QU/iw8IIdrG61vy4k2Fk8qzTZ57LZqer+7MkAZO4LeRfj1Gy1rBG9/e 4wfGs9YVTnbXNyKdkh2+YhZ042/hVw10WfapflKimHWexGxC+t0zdlqttzGgfm7RXyDCb2 dNJWrr4ZYfFch5urRQFFg+WVWF/ztyw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-65-bf-r7in0M06c7jk76TEC-w-1; Thu, 02 Apr 2020 02:12:53 -0400 X-MC-Unique: bf-r7in0M06c7jk76TEC-w-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 46FC7107ACCD; Thu, 2 Apr 2020 06:12:51 +0000 (UTC) Received: from [10.72.8.19] (ovpn-8-19.pek2.redhat.com [10.72.8.19]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 88FB989F0A; Thu, 2 Apr 2020 06:12:43 +0000 (UTC) Subject: Re: [PATCH 2/3] mm/memory_hotplug: Allow arch override of non boot memory resource names To: Dave Young , James Morse References: <20200326180730.4754-1-james.morse@arm.com> <20200326180730.4754-3-james.morse@arm.com> <20200402054946.GA97238@dhcp-128-65.nay.redhat.com> Cc: kexec@lists.infradead.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, Anshuman Khandual , Catalin Marinas , Bhupesh Sharma , Eric Biederman , Andrew Morton , Will Deacon , Hari Bathini From: piliu Message-ID: <9725d779-e0de-2d8d-8716-22df3e791820@redhat.com> Date: Thu, 2 Apr 2020 14:12:39 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <20200402054946.GA97238@dhcp-128-65.nay.redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 04/02/2020 01:49 PM, Dave Young wrote: > On 03/26/20 at 06:07pm, James Morse wrote: >> Memory added to the system by hotplug has a 'System RAM' resource created >> for it. This is exposed to user-space via /proc/iomem. >> >> This poses problems for kexec on arm64. If kexec decides to place the >> kernel in one of these newly onlined regions, the new kernel will find >> itself booting from a region not described as memory in the firmware >> tables. >> >> Arm64 doesn't have a structure like the e820 memory map that can be >> re-written when memory is brought online. Instead arm64 uses the UEFI >> memory map, or the memory node from the DT, sometimes both. We never >> rewrite these. > > Could arm64 use similar way to update DT, or a cooked UEFI maps? > > Add pingfan in cc, he said ppc64 update the DT after a memremove thus it > would be good to just redo a kexec load. > Yes, the memory changes will be observed through device-node under /proc/device-tree/ (which is for powerpc). Later if running kexec -l/-p , it can build new dtb with the latest info from /proc/device-tree > Added Pingfan and Hari for comments and corrections. > >> >> Allow an architecture to specify a different name for these hotplug >> regions. >> >> Signed-off-by: James Morse >> --- >> mm/memory_hotplug.c | 6 +++++- >> 1 file changed, 5 insertions(+), 1 deletion(-) >> >> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c >> index 0a54ffac8c68..69b03dd7fc74 100644 >> --- a/mm/memory_hotplug.c >> +++ b/mm/memory_hotplug.c >> @@ -42,6 +42,10 @@ >> #include "internal.h" >> #include "shuffle.h" >> >> +#ifndef MEMORY_HOTPLUG_RES_NAME >> +#define MEMORY_HOTPLUG_RES_NAME "System RAM" >> +#endif >> + >> /* >> * online_page_callback contains pointer to current page onlining function. >> * Initially it is generic_online_page(). If it is required it could be >> @@ -103,7 +107,7 @@ static struct resource *register_memory_resource(u64 start, u64 size) >> { >> struct resource *res; >> unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; >> - char *resource_name = "System RAM"; >> + char *resource_name = MEMORY_HOTPLUG_RES_NAME; >> >> if (start + size > max_mem_size) >> return ERR_PTR(-E2BIG); >> -- >> 2.25.1 >> >> >> _______________________________________________ >> kexec mailing list >> kexec@lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/kexec >>