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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 1DA6EC433E0 for ; Tue, 5 Jan 2021 05:43:10 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B1938225AB for ; Tue, 5 Jan 2021 05:43:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B1938225AB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id E28298D0054; Tue, 5 Jan 2021 00:43:08 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id DD9438D0036; Tue, 5 Jan 2021 00:43:08 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CEFE38D0054; Tue, 5 Jan 2021 00:43:08 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0207.hostedemail.com [216.40.44.207]) by kanga.kvack.org (Postfix) with ESMTP id BBFD38D0036 for ; Tue, 5 Jan 2021 00:43:08 -0500 (EST) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 7FFC6180AD807 for ; Tue, 5 Jan 2021 05:43:08 +0000 (UTC) X-FDA: 77670628056.08.patch31_6105c22274d6 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin08.hostedemail.com (Postfix) with ESMTP id 66AC11819E76B for ; Tue, 5 Jan 2021 05:43:08 +0000 (UTC) X-HE-Tag: patch31_6105c22274d6 X-Filterd-Recvd-Size: 3968 Received: from mail-ej1-f51.google.com (mail-ej1-f51.google.com [209.85.218.51]) by imf26.hostedemail.com (Postfix) with ESMTP for ; Tue, 5 Jan 2021 05:43:06 +0000 (UTC) Received: by mail-ej1-f51.google.com with SMTP id w1so39694458ejf.11 for ; Mon, 04 Jan 2021 21:43:06 -0800 (PST) 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=9CmvrTwTOLCxJGYA+L8vnsRq7pQdWjB2uBzHiEQLghE=; b=DFQdiZejzRJBlir0ay06r5fcQjz1D4NsJMshTXAaljvFFeyP7wL9+zPXDd7Iq0AOIS K9SYOsvsRghXdb/P9VdoFn4vse4IhNSpWOdZ8PPLRLrjqGNx+D8+B5uzjwvdcf6xuI8U am6QCDKfMmrsKEd9PynpGihEhDpF/Ak0JDCvmiXWf+z43jJDYNyWcbG1ZNiE8Blw5+s9 x+JgMNkpd/uvGISykRZZAEThjgfWVxU+qy1NJB4oPrYxekRVqZ6PUoVmp5/iogkGIg9I Kiy5epIb330ep1CdBZ9hpKsYiql2JVan0j3qpRncU5e/LQTccmQ1D1RJBaxlnreEa1lr ooBQ== 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=9CmvrTwTOLCxJGYA+L8vnsRq7pQdWjB2uBzHiEQLghE=; b=RJbtqOX0fCHQBbDgcnJBATOAiZmP8YMX5XGpM9MKVXAXzivunAvlG4xrFvE2iWXFa/ 8/rUCz8lFMnHSJnoLhhM03zREE2ANA/Ky5xXMRnYD4I6iWd+rw+HkNHGPC9L38upics3 yr0qbKEodKxEcMXbFS78Hvb+dSOjtZaL4w2Zzu6RGyOoaYAuyBnYhwfg1gG+B4ZDcfxg 9I38tLXY/rg0qkmKmk+bN3TXVaJXaax/96HuiAEnej1YESMPohw2NPb8/c50gli4lTdp ALGnrBL+HgXj24tTsjzlcN+gs9s9lF36ZJrvjiyrHWYSedu5EMeVX4eHo6fUWyaFIWfQ aFZg== X-Gm-Message-State: AOAM531i1JR1RkWkDtXidV4Q5luy4qZJh4O5XcEv6ok2q3sO0vLUsdeT cW1hg9hqEEzzKA/RWc4ghCkiFIDrUznwNMK1fBG8YQ== X-Google-Smtp-Source: ABdhPJx7m/Sf0ohBHUMCtWefo85ADNjmKH0VHW7sKIZoRIr8AXB9Bw3Shm9m7fih9e4QeOv1njHPYp+1UN1nW3Djk94= X-Received: by 2002:a17:906:a29a:: with SMTP id i26mr68498113ejz.45.1609825385802; Mon, 04 Jan 2021 21:43:05 -0800 (PST) MIME-Version: 1.0 References: <20201231053156.24276-1-zhuling8@huawei.com> In-Reply-To: <20201231053156.24276-1-zhuling8@huawei.com> From: Dan Williams Date: Mon, 4 Jan 2021 21:42:59 -0800 Message-ID: Subject: Re: [PATCH] arm64: add pmem module for kernel update To: Zhuling Cc: Linux Kernel Mailing List , Linux ARM , linux-nvdimm , Linux MM , Will Deacon , Vishal L Verma , Dave Jiang , luanjianhai@huawei.com, luchunhua@huawei.com, sangyan@huawei.com Content-Type: text/plain; charset="UTF-8" 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: Hi Zhuling, On Wed, Dec 30, 2020 at 10:18 PM Zhuling wrote: > > Category: feature > Bugzilla: NA > CVE: NA These tags can be dropped. > > Use reserved memory to create a pmem device to store the > processes information that dumped before kernel update. > When you want to use this feature you need to declare by > "pmemmem=pmem_size:pmem_phystart" in cmdline. > (exp: pmemmem=100M:0x202000000000) > Interesting. I like the feature, but it's not clear to me that a new command line based configuration scheme is needed. There is the existing memmap= parameter that on x86 describes a IORES_DESC_PERSISTENT_MEMORY_LEGACY range. The driver/nvdimm/e820.c driver could be reworked to attach to the same thing on ARM64. Then as far as assigning memory to different kernel usages there is the existing capability in libnvdimm to attach a "personality" to an nvdimm namespace. I imagine you could write a special signature to the namespace that libnvdimm would recognize as a KUP reservation namespace and work generically across any arch.