From nobody Fri Dec 19 07:21:41 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 64C631B2509; Fri, 30 Aug 2024 14:04:20 +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=1725026672; cv=none; b=MbPeAyQxuvkroFHoIn5yDErtuyPu0iwXaHpZytnjSa+qbPlYkffxjW+/3MOn2zJOW4eH9qJumFLfWKmPcDU2EY/M03RMCK0TD5PwM68IGvvOhU+eyAO78pthlto4ilspos1Y4hdEGWnlTQZXn6irIOhAXbYO7e765s5bx8hHbCw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725026672; c=relaxed/simple; bh=ordtzeKGfZ9tzbNzAMjuXb1IZc/l+GZwq+W62hzwnn4=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=FJVmP0+phHmPcxAJpS6R/1QBJfPG/Z57XeM0RC/jHnRRfK4gpm8g/sHiahIdvZfxGtCfGFLypS7+GIKbnennwzVxGgLV3KA8ROoyW+kTcKmAKPTO6X8iHosqWTjhxDPSXmsMP7wUTXP903sYCNtXt03cbWPF7xP9dS5kT+DISWE= 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=oV0O0fTB; 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="oV0O0fTB" 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=g7u3JY1dUMc3W4JVQxtJZrZEzcHPVuAghUUeOne4iAY=; b=oV0O0fTBZZfPvlMEar3HxRPa0R 60yLSGtHnZeL//MGhGu2vHwUSUo5HxT8qquoOyBGnBJNR7LJE1NUbQ05R0hqFX+0Fi/e1l1wa/ctr G8fnCLEOVdVU2mg3Dnc3k7sAP1m2w0+tnKWn+lFobslVpqkPbK2uPvDm3wmQgxMBnbntetzGHLqiD +oiuRhbx7V/x2BisNbLierYpDp154lb/OHLrlQgI46cSo8M9hj/zPAiXTCmZz4bZVOhI8CeNi7b3l XcKv2NoG3gg0a2k/b1ezD4vA3ZLg6YmD7aRuiBwc4eZ5ixf21Q4aNuCakkxZDC6BvpILj+qISMj/v gK6Dsy4Q==; 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 1sk2Ea-007AjX-Ae; Fri, 30 Aug 2024 16:04:16 +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] Documentation: Improve crash_kexec_post_notifiers description Date: Fri, 30 Aug 2024 11:03:22 -0300 Message-ID: <20240830140401.458542-1-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. Signed-off-by: Guilherme G. Piccoli Reviewed-by: Stephen Brennan --- 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..cb25dc5cbe9a 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. As a bright + side, it might allow to collect more data on dmesg like + stack traces from other CPUs or extra data dumped by + panic_print. This is usually only for users who doubt + kdump will succeed every time. 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