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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 7E8E5C43381 for ; Mon, 11 Mar 2019 09:06:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 577C1206BA for ; Mon, 11 Mar 2019 09:06:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727045AbfCKJGL (ORCPT ); Mon, 11 Mar 2019 05:06:11 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38024 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725839AbfCKJGL (ORCPT ); Mon, 11 Mar 2019 05:06:11 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A4CD2308A953; Mon, 11 Mar 2019 09:06:10 +0000 (UTC) Received: from dhcp-128-65.nay.redhat.com (ovpn-12-113.pek2.redhat.com [10.72.12.113]) by smtp.corp.redhat.com (Postfix) with ESMTPS id F21E95DD8D; Mon, 11 Mar 2019 09:05:56 +0000 (UTC) Date: Mon, 11 Mar 2019 17:05:53 +0800 From: Dave Young To: Bhupesh Sharma Cc: linux-kernel@vger.kernel.org, Mark Rutland , Kazuhito Hagio , Michael Ellerman , x86@kernel.org, Will Deacon , linuxppc-dev@lists.ozlabs.org, kexec@lists.infradead.org, James Morse , linux-arm-kernel@lists.infradead.org, Benjamin Herrenschmidt , Boris Petkov , Thomas Gleixner , bhupesh.linux@gmail.com, Dave Anderson , Ingo Molnar , Paul Mackerras Subject: Re: [PATCH v2 0/2] Append new variables to vmcoreinfo (PTRS_PER_PGD for arm64 and MAX_PHYSMEM_BITS for all archs) Message-ID: <20190311090553.GA12130@dhcp-128-65.nay.redhat.com> References: <1552212242-9479-1-git-send-email-bhsharma@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1552212242-9479-1-git-send-email-bhsharma@redhat.com> User-Agent: Mutt/1.9.5 (2018-04-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.41]); Mon, 11 Mar 2019 09:06:11 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Bhupesh, On 03/10/19 at 03:34pm, Bhupesh Sharma wrote: > Changes since v1: > ---------------- > - v1 was sent out as a single patch which can be seen here: > http://lists.infradead.org/pipermail/kexec/2019-February/022411.html > > - v2 breaks the single patch into two independent patches: > [PATCH 1/2] appends 'PTRS_PER_PGD' to vmcoreinfo for arm64 arch, whereas > [PATCH 2/2] appends 'MAX_PHYSMEM_BITS' to vmcoreinfo in core kernel code (all archs) > > This patchset primarily fixes the regression reported in user-space > utilities like 'makedumpfile' and 'crash-utility' on arm64 architecture > with the availability of 52-bit address space feature in underlying > kernel. These regressions have been reported both on CPUs which don't > support ARMv8.2 extensions (i.e. LVA, LPA) and are running newer kernels > and also on prototype platforms (like ARMv8 FVP simulator model) which > support ARMv8.2 extensions and are running newer kernels. > > The reason for these regressions is that right now user-space tools > have no direct access to these values (since these are not exported > from the kernel) and hence need to rely on a best-guess method of > determining value of 'PTRS_PER_PGD' and 'MAX_PHYSMEM_BITS' supported > by underlying kernel. > > Exporting these values via vmcoreinfo will help user-land in such cases. > In addition, as per suggestion from makedumpfile maintainer (Kazu) > during v1 review, it makes more sense to append 'MAX_PHYSMEM_BITS' to > vmcoreinfo in the core code itself rather than in arm64 arch-specific > code, so that the user-space code for other archs can also benefit from > this addition to the vmcoreinfo and use it as a standard way of > determining 'SECTIONS_SHIFT' value in user-land. > > Cc: Mark Rutland > Cc: James Morse > Cc: Will Deacon > Cc: Boris Petkov > Cc: Ingo Molnar > Cc: Thomas Gleixner > Cc: Michael Ellerman > Cc: Paul Mackerras > Cc: Benjamin Herrenschmidt > Cc: Dave Anderson > Cc: Kazuhito Hagio > Cc: x86@kernel.org > Cc: linuxppc-dev@lists.ozlabs.org > Cc: linux-arm-kernel@lists.infradead.org > Cc: linux-kernel@vger.kernel.org > Cc: kexec@lists.infradead.org > > Bhupesh Sharma (2): > arm64, vmcoreinfo : Append 'PTRS_PER_PGD' to vmcoreinfo > crash_core, vmcoreinfo: Append 'MAX_PHYSMEM_BITS' to vmcoreinfo > > arch/arm64/kernel/crash_core.c | 1 + > kernel/crash_core.c | 1 + > 2 files changed, 2 insertions(+) > Lianbo's document patch has been merged, would you mind to add vmcoreinfo doc patch as well in your series? Thanks Dave