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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_MED, 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 DE88BECDFD0 for ; Fri, 14 Sep 2018 17:40:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9A11220853 for ; Fri, 14 Sep 2018 17:40:55 +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="H6xOLBXz" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9A11220853 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728126AbeINW4Y (ORCPT ); Fri, 14 Sep 2018 18:56:24 -0400 Received: from mail-ot1-f45.google.com ([209.85.210.45]:41242 "EHLO mail-ot1-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727691AbeINW4X (ORCPT ); Fri, 14 Sep 2018 18:56:23 -0400 Received: by mail-ot1-f45.google.com with SMTP id e18-v6so5350303oti.8 for ; Fri, 14 Sep 2018 10:40:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=LNjGpuLxCcWQWpdF58YgOaCxoCjPp8J7c7Q6w8SmxjU=; b=H6xOLBXzlW97tBQ97/WUw94R8NspYYsGCOOg25OVWQpCe0LcD/ZTN9p7VtuNx730HW 6qXaRsmuQxjUKnv0ckMhj3QcMS3wGN3N8lGsPNfzZCB4DsZF6tVHE/yU4hcUxTxCy0z5 RAbiguTAndXUPngquxvFKrwu3BhKcqoa8VGb0qL8LxGZeBXEPtin5pIcZQ5rm/wj5zos +v6OddKOWSpOfU0MbEERxZ+mP3wsENfP2jeDhhFGB279VFcBtzf+2Ifid3iQ/b+I0NlX Z7JJwiJoasFJD8ui+eBgBhAT27iS1PYSgA2eHne/8WuzPx8SCj961zHiuRsW791U63+9 ocRQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=LNjGpuLxCcWQWpdF58YgOaCxoCjPp8J7c7Q6w8SmxjU=; b=rb7UPVFjQRxF1DasoT/ncKNTYFJKExEEgG7s/dASBeAVwuPbPEa8dKra7oXI4JBRjb 8c8oJK5ubrUAcIE0Nx6W6fyRUXMadf+YocaUjMKTnrtJ7UTh0lFz8YyhQhmD39TAOVqT GsnMqfKGOSHNb5d9WFW27a3e0vpEUOwma3/rJBONyCaRYgn917eZ0nzMcatjd0bwlB3g L84CUXfybaAoyo3kiGjNl0CQgL3d9GYXSl6YIJTk9wuCP7txCoosXJiLBNWfUqJ6HORE Smry8H3qjPDqV5ZqZIqsrWvUC59LJglWH04cxtRgeUAvSYH3T05pQYLoleRb4h2v2sOU SotQ== X-Gm-Message-State: APzg51AbIKlvj+fvukSHd/j2p3O3Amy+4UQ8fk1/5tOOgna47aeMxxrK 7+8rMvwCuAVfc72OtRFChCEkVCxsioOheGmdQ+IuXg== X-Google-Smtp-Source: ANB0VdYNzziC2fHIcxoLoIMMwrzj+qmwF+yMkyIRQGXf4fJs2HmWdFL/63XouVUZkOKOgcC9xVxciy+W+CXIB8t9dMU= X-Received: by 2002:a9d:7353:: with SMTP id l19-v6mr4863094otk.7.1536946853053; Fri, 14 Sep 2018 10:40:53 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a4a:8e85:0:0:0:0:0 with HTTP; Fri, 14 Sep 2018 10:40:52 -0700 (PDT) In-Reply-To: <20180914131420.GC27141@lst.de> References: <153680531988.453305.8080706591516037706.stgit@dwillia2-desk3.amr.corp.intel.com> <153680533172.453305.5701902165148172434.stgit@dwillia2-desk3.amr.corp.intel.com> <20180914131420.GC27141@lst.de> From: Dan Williams Date: Fri, 14 Sep 2018 10:40:52 -0700 Message-ID: Subject: Re: [PATCH v5 2/7] mm, devm_memremap_pages: Kill mapping "System RAM" support To: Christoph Hellwig Cc: Andrew Morton , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Logan Gunthorpe , Alexander Duyck , Linux MM , Linux Kernel Mailing List 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 Fri, Sep 14, 2018 at 6:14 AM, Christoph Hellwig wrote: > On Wed, Sep 12, 2018 at 07:22:11PM -0700, Dan Williams wrote: >> Given the fact that devm_memremap_pages() requires a percpu_ref that is >> torn down by devm_memremap_pages_release() the current support for >> mapping RAM is broken. > > I agree. Do you remember why we even added it in the first place? It was initially a copy over from memremap() that catches these attempts and returns a direct-map pointer.