From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f197.google.com (mail-qk0-f197.google.com [209.85.220.197]) by kanga.kvack.org (Postfix) with ESMTP id F35DB6B000A for ; Wed, 23 May 2018 14:24:18 -0400 (EDT) Received: by mail-qk0-f197.google.com with SMTP id d71-v6so6738772qkg.0 for ; Wed, 23 May 2018 11:24:18 -0700 (PDT) Received: from mx1.redhat.com (mx3-rdu2.redhat.com. [66.187.233.73]) by mx.google.com with ESMTPS id p43-v6si2391380qtg.155.2018.05.23.11.24.18 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 23 May 2018 11:24:18 -0700 (PDT) From: David Hildenbrand Subject: [PATCH RFCv2 2/4] s390: mm: support removal of memory Date: Wed, 23 May 2018 20:24:02 +0200 Message-Id: <20180523182404.11433-3-david@redhat.com> In-Reply-To: <20180523182404.11433-1-david@redhat.com> References: <20180523182404.11433-1-david@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, David Hildenbrand , Martin Schwidefsky , Heiko Carstens , Vlastimil Babka , Michal Hocko , Andrew Morton , Greg Kroah-Hartman , linux-s390@vger.kernel.org With virtio-mem, we actually want to remove memory again. Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Vlastimil Babka Cc: Michal Hocko Cc: Andrew Morton Cc: Greg Kroah-Hartman Cc: linux-s390@vger.kernel.org Signed-off-by: David Hildenbrand --- arch/s390/mm/init.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index 3fa3e5323612..7202344d0eae 100644 --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -242,12 +242,18 @@ int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap, #ifdef CONFIG_MEMORY_HOTREMOVE int arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap) { - /* - * There is no hardware or firmware interface which could trigger a - * hot memory remove on s390. So there is nothing that needs to be - * implemented. - */ - return -EBUSY; + const unsigned long start_pfn = start >> PAGE_SHIFT; + const unsigned long nr_pages = size >> PAGE_SHIFT; + struct page *page = pfn_to_page(start_pfn); + struct zone *zone; + int ret; + + zone = page_zone(page); + ret = __remove_pages(zone, start_pfn, nr_pages, altmap); + WARN_ON_ONCE(ret); + vmem_remove_mapping(start, size); + + return ret; } #endif #endif /* CONFIG_MEMORY_HOTPLUG */ -- 2.17.0