From nobody Fri Dec 19 07:21:14 2025 Received: from fanzine2.igalia.com (fanzine.igalia.com [178.60.130.6]) (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 148B81B3B13; Fri, 30 Aug 2024 18:22:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.60.130.6 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725042154; cv=none; b=lrqRXFjKbY1d11182G3uqwCkRVQyqQXHDMzVx12Jov2yWAVwv4Z09y7afeNdvC9hpCa8Rzug8qptc7pcEt14i8z6TT7StoIXxLYX5Na1tkYzWpopSUhYhtlR2ZYE0QZQVK5EZmDuJHUdwee6y+hSChMU4YaOeVyANmgmdqDKn0I= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725042154; c=relaxed/simple; bh=iPxydC4ULYzP46EMCs+sJA3UlXi9bBkH3ecEvdhSCGY=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=YjnvUReovYXvq/Ia22nzAi9iOeIjEYktfYsJFyaKX8B9FNbaN10/6xxvM+wqMd8hCg3k7943OVlWkoKwV5LDzlJklRlNvPd8eF6zRi/BP+jQWU6ukav9WJBYMcN5WvwGWSTNHtotu6fO/nDn1ingUSJmMXSpVtTSVSGOCPlfvqE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com; spf=pass smtp.mailfrom=igalia.com; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b=OtV0fUNI; arc=none smtp.client-ip=178.60.130.6 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=igalia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b="OtV0fUNI" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:MIME-Version:Message-ID:Date:Subject: Cc:To:From:Sender:Reply-To:Content-Type:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: In-Reply-To:References:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=XWs/60Qc8mo1giESc1/N4HmXbyxb+7YdXNX6HnpRBCU=; b=OtV0fUNIDfaWkHgpb3KMRcLC3v AzZYRTyliGxqXDzs4pqNPXKUF3ZqTR7nkzVLMdYpleK34l5IOPZkmTr2NSTWTjJQnId1xGwP8paoS tit50STIJCBGTEZzWwifFzoqa6C+nfoluKliWxi+BjzVH+uvjE2q+Bwv2dpqSr3EITFJFNX2cNFJc IGiljaaIWKOjU5TXN9tG95F+gg5JL1UO8KK/VZpY833b07KbDEEc176FkJWbRCJp8O/8GYYn7NvGx 6mczZSc8Lu7DXNpJC/DrR6lRXl2OVYzTzf5T47TuI+jhdBbjugqc+gY7FWc9bkQUFxbqVvYkLAJSU wzpbnmyg==; Received: from [177.76.152.96] (helo=localhost) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1sk6GS-007FWw-Dk; Fri, 30 Aug 2024 20:22:28 +0200 From: "Guilherme G. Piccoli" To: kexec@lists.infradead.org, linux-doc@vger.kernel.org Cc: bhe@redhat.com, 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, "Guilherme G. Piccoli" Subject: [PATCH V2] Documentation: Improve crash_kexec_post_notifiers description Date: Fri, 30 Aug 2024 15:21:00 -0300 Message-ID: <20240830182219.485065-1-gpiccoli@igalia.com> X-Mailer: git-send-email 2.46.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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/Documentatio= n/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. =20 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. =20 crashkernel=3Dsize[KMG][@offset[KMG]] [KNL,EARLY] Using kexec, Linux can switch to a 'crash kernel' --=20 2.46.0