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=-6.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED 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 B2A30C004C9 for ; Tue, 7 May 2019 20:46:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8135D20449 for ; Tue, 7 May 2019 20:46:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=intel-com.20150623.gappssmtp.com header.i=@intel-com.20150623.gappssmtp.com header.b="rqW6lucK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727159AbfEGUqU (ORCPT ); Tue, 7 May 2019 16:46:20 -0400 Received: from mail-ot1-f65.google.com ([209.85.210.65]:43717 "EHLO mail-ot1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726602AbfEGUqT (ORCPT ); Tue, 7 May 2019 16:46:19 -0400 Received: by mail-ot1-f65.google.com with SMTP id i8so6580548oth.10 for ; Tue, 07 May 2019 13:46:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Fw0JPQ4oQ07pMZfSEOmqFo0Ax/JNe6lqDNiuIeW+cfk=; b=rqW6lucK5GLSkk6D3VC83NNNr3p5l4cDVk4n80Uvm322BBV2qCuKSPr4z+P2ezcoyK z+YMgkO0V+5hEmcMr0MwF6O3QHG8xWVY2eTA1Py3k6awm18aqMlPP98eZujqBEdbRRXN aS93k1uMcPJFXIHF98HnDfB8WCQgSAWAn+PzoKcCdVTC+uJmNJ+7TTcrUEmBZNFgGikS JoN377FDE4nzpHgH/fCwVvnpugUJXF2ApAVZaCrgrLXf7ZjFcE/OLNwmWNUpvbW/wIQU Uwg4mKk8U4/mWeh5D1XY1VYZpFjHtv4IPmwLoWQVjBRPrwTp5axa3EA9O5FG/AT874cG VNvQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Fw0JPQ4oQ07pMZfSEOmqFo0Ax/JNe6lqDNiuIeW+cfk=; b=f++pIaRooovwmZEJ/4JgSOmsWVKE9lchVzCIpwzR7yqwufqrGytQEz3/rcCVrozvbn siI6BJ2/lcemoAXiQEPtkVdFWpCgyfxxxGlwZ2VIqMeCdcPevQluiVNFk9uKGrIVPXUo C10WGQBdyQOl46Avscqe/gNg23zD74dhV3qUl9A78aSY9f09tl/Xhp07oR3jBFLRHJKP 1if18fcwgm/atoLNOv8RB9uxD12FH6LTcf8EwnLgWs/5YC9iOPB5HdJhgTqlG6KZE4+7 fm/5TD9+HjG15VlPQD7n6JAIAwFhLys/BJeZoUTMBAKNgU3mhD72FpFqWTqSs+70TZQh SZHQ== X-Gm-Message-State: APjAAAVp0aq2i7Lm5pO7Jk96hOrFBbWcC5oqf0SRfyAA9FaNNVIpvzyx wml8zG3NE6ejv0cXrVB2GCqbbY3Gg6CQ1wcbCRZfsg== X-Google-Smtp-Source: APXvYqwkL7vHIYJxD+HfiXZUkr4PGh3XR7bd+koUKuRLubXL7y6kGEyKk74Z2RGz0ad/moc44qYziRyn+VmkpRZHHO8= X-Received: by 2002:a9d:6f19:: with SMTP id n25mr2402081otq.367.1557261979262; Tue, 07 May 2019 13:46:19 -0700 (PDT) MIME-Version: 1.0 References: <20190507183804.5512-1-david@redhat.com> <20190507183804.5512-3-david@redhat.com> In-Reply-To: <20190507183804.5512-3-david@redhat.com> From: Dan Williams Date: Tue, 7 May 2019 13:46:08 -0700 Message-ID: Subject: Re: [PATCH v2 2/8] s390x/mm: Implement arch_remove_memory() To: David Hildenbrand Cc: Linux MM , Linux Kernel Mailing List , linux-ia64@vger.kernel.org, linuxppc-dev , linux-s390 , Linux-sh , Andrew Morton , Martin Schwidefsky , Heiko Carstens , Michal Hocko , Mike Rapoport , Vasily Gorbik , Oscar Salvador Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 7, 2019 at 11:38 AM David Hildenbrand wrote: > > Will come in handy when wanting to handle errors after > arch_add_memory(). > > Cc: Martin Schwidefsky > Cc: Heiko Carstens > Cc: Andrew Morton > Cc: Michal Hocko > Cc: Mike Rapoport > Cc: David Hildenbrand > Cc: Vasily Gorbik > Cc: Oscar Salvador > Signed-off-by: David Hildenbrand > --- > arch/s390/mm/init.c | 13 +++++++------ > 1 file changed, 7 insertions(+), 6 deletions(-) > > diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c > index 31b1071315d7..1e0cbae69f12 100644 > --- a/arch/s390/mm/init.c > +++ b/arch/s390/mm/init.c > @@ -237,12 +237,13 @@ int arch_add_memory(int nid, u64 start, u64 size, > void arch_remove_memory(int nid, 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. > - */ > - BUG(); > + unsigned long start_pfn = start >> PAGE_SHIFT; > + unsigned long nr_pages = size >> PAGE_SHIFT; > + struct zone *zone; > + > + zone = page_zone(pfn_to_page(start_pfn)); Does s390 actually support passing in an altmap? If 'yes', I think it also needs the vmem_altmap_offset() fixup like x86-64: /* With altmap the first mapped page is offset from @start */ if (altmap) page += vmem_altmap_offset(altmap); ...but I suspect it does not support altmap since arch/s390/mm/vmem.c::vmemmap_populate() does not arrange for 'struct page' capacity to be allocated out of an altmap defined page pool. I think it would be enough to disallow any arch_add_memory() on s390 where @altmap is non-NULL. At least until s390 gains ZONE_DEVICE support and can enable the pmem use case.