From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Date: Mon, 11 Mar 2019 17:05:53 +0800 From: Dave Young 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-Disposition: inline In-Reply-To: <1552212242-9479-1-git-send-email-bhsharma@redhat.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Bhupesh Sharma Cc: Mark Rutland , Kazuhito Hagio , Michael Ellerman , x86@kernel.org, Will Deacon , linux-kernel@vger.kernel.org, Ingo Molnar , Paul Mackerras , James Morse , Benjamin Herrenschmidt , Boris Petkov , Thomas Gleixner , bhupesh.linux@gmail.com, linuxppc-dev@lists.ozlabs.org, kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org, Dave Anderson 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 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec