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=-5.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS 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 44EDEC433E0 for ; Tue, 9 Jun 2020 05:29:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1E7C1207ED for ; Tue, 9 Jun 2020 05:29:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727915AbgFIF3N (ORCPT ); Tue, 9 Jun 2020 01:29:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39856 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727888AbgFIF3G (ORCPT ); Tue, 9 Jun 2020 01:29:06 -0400 Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1BFC4C03E969 for ; Mon, 8 Jun 2020 22:29:06 -0700 (PDT) Received: by ozlabs.org (Postfix, from userid 1034) id 49gzF70kkGz9sTH; Tue, 9 Jun 2020 15:28:58 +1000 (AEST) From: Michael Ellerman To: Thomas Gleixner , Greg Kroah-Hartman , Christophe Leroy , Alexios Zavras , Leonardo Bras , Paul Mackerras , Benjamin Herrenschmidt , Michael Ellerman , Enrico Weigelt Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org In-Reply-To: <20200512214533.93878-1-leobras.c@gmail.com> References: <20200512214533.93878-1-leobras.c@gmail.com> Subject: Re: [PATCH v2 1/1] powerpc/crash: Use NMI context for printk when starting to crash Message-Id: <159168034498.1381411.5705399954174028060.b4-ty@ellerman.id.au> Date: Tue, 9 Jun 2020 15:28:58 +1000 (AEST) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 12 May 2020 18:45:35 -0300, Leonardo Bras wrote: > Currently, if printk lock (logbuf_lock) is held by other thread during > crash, there is a chance of deadlocking the crash on next printk, and > blocking a possibly desired kdump. > > At the start of default_machine_crash_shutdown, make printk enter > NMI context, as it will use per-cpu buffers to store the message, > and avoid locking logbuf_lock. Applied to powerpc/next. [1/1] powerpc/crash: Use NMI context for printk when starting to crash https://git.kernel.org/powerpc/c/af2876b501e42c3fb5174cac9dd02598436f0fdf cheers