Received: by 2002:a25:683:0:0:0:0:0 with SMTP id 125csp242771ybg; Mon, 8 Jun 2020 22:33:32 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxn7CEWXJgBx9BDG/ALnRK4JNUKDU2vdHDTtt1Uj7CDhHVx6CKuB3gzOWShhwDiIEEpp1pp X-Received: by 2002:a17:906:cd06:: with SMTP id oz6mr25261042ejb.434.1591680812076; Mon, 08 Jun 2020 22:33:32 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1591680812; cv=none; d=google.com; s=arc-20160816; b=bIxsMW6mylI3DDK3dfUztsQHc0hm6HdkijRjZXwLDBlPYAQZIWgdLqNicmDctfbAia ugsLxim7IPx21dRqGjlPqzs1X7xOKNBzIMvOxjQY+pkwI5CuPOfkYx/pSnsKKjqzYyg+ JwHgQbayN0tz2r8O0nT0Z38soN8LRme552/sty9gMhTAQLjP7gvC5ByfMJ3j+CiFGZiy lEsq7zUXlExHUgPeGI7RpaxWdHyfU3eMGeOX9a+YE4mgNSCUjgY8R0WwW/tU9pDZt8PL +ya+or0wZQx255GG11OXppA0HnilJniL9aFaCIpz633xN2IHaU+d+SFW51FECmkODPkJ T6GA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:date:message-id:subject:references :in-reply-to:cc:to:from; bh=QvGt0DdnV9+f4LgV0XysAPAKgnlmFYAIlvUXqpaRYo8=; b=F40fc2TUrUDiL5ZYisX1p6VuaBk/66qrXyEvna7KLvwjLIbfKvdmom2zaICHfKofks DTaa2ZFfKycwU9gUsHBlyA1uXFf1Tp72y7VzwLYOXafzKaLS5IwAvJUGNhGPglpYaHG9 8n1P7miz1gV7OxSDZG8C2SXD8dqBG+TpKLyZ1mBIoQYTf77QIk109Yefnq4BKnrxfF5T deSKo1wrrZxtPGlBwhYczKBgKsGzCOM4XBoBVKFPta3gDac9Zl8ig8n5UTVMDWJO8bm2 1/Dp7KcCoOC1oquMWc98znNFS+d8m+EXZHx8i5pEkoRyLJwa8Dr0yI/Gagqxuw4QLJJW d6NQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id n1si9701490edy.216.2020.06.08.22.33.09; Mon, 08 Jun 2020 22:33:32 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727910AbgFIF3L (ORCPT + 99 others); Tue, 9 Jun 2020 01:29:11 -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