From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 309F517C61 for ; Thu, 12 Sep 2024 00:54:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726102463; cv=none; b=J3VafxvwYdPXvkOnMaW11MZHcPDf5Hp69/OajppkNdHZQJ5R/hRAgzZmlWRv003Vnim2A7V7v4X5LXBCtAhKIy5SCO2Tf3692SVPgWDxLQmnjTbh+fAokn/fNixpECkUHoduQ9HTyUx9Uu2jxGVvr9yy4/Bmw+0yKrFUsg/RdaM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726102463; c=relaxed/simple; bh=G7GLqn0KRULSA/DzBkbf6bmbo4/NSkTPF7BwhLKPfZc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=kd2mjeb0vWO2na7LcrGgD+pcGLbsLsd8tDM3NnvltrUM9aRdnqioJg1PRSplWZ3UhKGnOq9KaeFMVWsTVeCZaUfdCysCZ7tIurOFaEt7i9wVzR5JIrY97vEDx57KZHndv7tMEaoCUcZm2GDzAV9jn9QpfuKPEulMRB+JD3+GfIk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=McZcCbfg; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="McZcCbfg" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1726102459; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=b68u0e0/6l3aTcwgwyF4H+GXM1gl+kB/qAh1zau1jhw=; b=McZcCbfg5Nd7nNng1NNW0LxHndGbch2wfLdAdMGKRwvy9vf6MfmJrYr+val5XRcc2Vr8sR +On6Fd512aFCXKhvpNgNbsizlShd4CVJMxgRYwpy11dd94ICiZYY5EmX4hnrk9YOy2hBl4 2pH/eb0rwcYSb2QnmQjhd/R2psIKwTk= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-18-xjkabQI1MU-6C18y-nGYWQ-1; Wed, 11 Sep 2024 20:54:15 -0400 X-MC-Unique: xjkabQI1MU-6C18y-nGYWQ-1 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 471501955F68; Thu, 12 Sep 2024 00:54:12 +0000 (UTC) Received: from localhost (unknown [10.72.112.58]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id DF62F19560A3; Thu, 12 Sep 2024 00:54:07 +0000 (UTC) Date: Thu, 12 Sep 2024 08:54:02 +0800 From: Baoquan He To: "Guilherme G. Piccoli" Cc: kexec@lists.infradead.org, linux-doc@vger.kernel.org, vgoyal@redhat.com, dyoung@redhat.com, corbet@lwn.net, linux-kernel@vger.kernel.org, linux-debuggers@vger.kernel.org, stephen.s.brennan@oracle.com, kernel@gpiccoli.net, kernel-dev@igalia.com Subject: Re: [PATCH V2] Documentation: Improve crash_kexec_post_notifiers description Message-ID: References: <20240830182219.485065-1-gpiccoli@igalia.com> Precedence: bulk X-Mailing-List: linux-debuggers@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 On 09/11/24 at 05:09pm, Guilherme G. Piccoli wrote: > On 02/09/2024 05:05, Baoquan He wrote: > > On 08/30/24 at 03:21pm, Guilherme G. Piccoli wrote: > >> Be more clear about the downsides, the upsides (yes, there are some!) > >> and about code that unconditionally sets that. > >> > >> Reviewed-by: Stephen Brennan > >> Signed-off-by: Guilherme G. Piccoli > >> > >> --- > >> > >> V2: Some wording improvements from Stephen, thanks! > >> Also added his review tag. > >> > >> V1 link: https://lore.kernel.org/r/20240830140401.458542-1-gpiccoli@igalia.com/ > >> > >> > >> Documentation/admin-guide/kernel-parameters.txt | 16 ++++++++++------ > >> 1 file changed, 10 insertions(+), 6 deletions(-) > >> > >> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > >> index efc52ddc6864..351730108c58 100644 > >> --- a/Documentation/admin-guide/kernel-parameters.txt > >> +++ b/Documentation/admin-guide/kernel-parameters.txt > >> @@ -913,12 +913,16 @@ > >> the parameter has no effect. > >> > >> crash_kexec_post_notifiers > >> - Run kdump after running panic-notifiers and dumping > >> - kmsg. This only for the users who doubt kdump always > >> - succeeds in any situation. > >> - Note that this also increases risks of kdump failure, > >> - because some panic notifiers can make the crashed > >> - kernel more unstable. > >> + Only jump to kdump kernel after running the panic > >> + notifiers and dumping kmsg. This option increases the > >> + risks of a kdump failure, since some panic notifiers > >> + can make the crashed kernel more unstable. In the > >> + configurations where kdump may not be reliable, > >> + running the panic notifiers can allow collecting more > >> + data on dmesg, like stack traces from other CPUS or > >> + extra data dumped by panic_print. Notice that some > >> + code enables this option unconditionally, like > >> + Hyper-V, PowerPC (fadump) and AMD SEV. > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > I know Hyper-V enable panic-notifiers by default, but don't remember how > > PowerPC and AMD SEC behave in this aspect. While at it, can you add a > > little more words to state them in log so that people can learn it? > > Thanks. > > > Hi Baoquan, tnx for the suggestion! You mean mention that in the commit > message? If so, I can certainly do - will sent a new version soon(tm) > and include it =) You are right, thanks for the effort.