From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from ms.lwn.net (ms.lwn.net [45.79.88.28]) (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 DAF9235677C; Mon, 24 Aug 2026 17:13:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.79.88.28 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787591621; cv=none; b=qbE/2TAkXuoDmMeM3j916pEHW00q5fEI/I845K8Z1hv7veDQYgWo1glr/00plq49tSzEru0zuiTQqgbmAnn5LSbe6EZLOmEjWHyOv+PbnO7zpmrFSN9qB6LZtzbO8NyV6G3XBeTVFpsM7ZXrMlRqxEWwIZVm4xYWyI6xV/PctdQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787591621; c=relaxed/simple; bh=WHwmqYZuEwhWcNjwwZlZRtHvZEY3zxBrShHl9ejLdyU=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=pZWeobiVIr7Iax9i47Iq4MyaSiMdsj499I2ala/Br8Mzcalj8iiYNOUPrZ1gplUnxbUrx3QL0KhXMlw8fy6vCGg6vgaIJSiCt4T4cQGl2qUmtr4XFU1y3f4PyTsUW/H+rRwXbcxJu55XV4L/qCcvFQZ8ma4J2vcrhRwiCXTTRog= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lwn.net; spf=pass smtp.mailfrom=lwn.net; dkim=pass (2048-bit key) header.d=lwn.net header.i=@lwn.net header.b=I5XMCCzr; arc=none smtp.client-ip=45.79.88.28 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lwn.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lwn.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=lwn.net header.i=@lwn.net header.b="I5XMCCzr" DKIM-Filter: OpenDKIM Filter v2.11.0 ms.lwn.net 2B185408F8 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lwn.net; s=20201203; t=1787591619; bh=GrjBxMDLFvDI4bL59EmOEI2m/q8sLn68ShjwW49xN88=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=I5XMCCzrLbpqyIsm8vQOdWPspSuMSgJJfld7F57ffW8zH+JOhYY03arv+x2aBPnoS lW6e606538m3WcrJWeIyjYBNoh6RXumPhfIqIAvoNmo7h0DcMj7wHGdegHK84oE01W nKRVLiEDoTjxSctj5K7OV9yzGD0DldDlM2ZAddpD9kRrNAQcyOq+A40whnn2PLVvf8 eeo49eSsh6LfH2xeADWDupWt7TuI6Rc9rei/hlHlMaItuDmMc9qFP0mrLGObcnPi7T /fRk1MrF0ztsYGFecLsuHZLQW5CsBS3rXGJj9854e25KOzpApem8VVBdvD3oySAHxR u2/7Sbp9fmJlw== Received: from localhost (unknown [IPv6:2601:280:4600:814::1fe]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (prime256v1) server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by ms.lwn.net (Postfix) with ESMTPSA id 2B185408F8; Mon, 24 Aug 2026 17:13:39 +0000 (UTC) From: Jonathan Corbet To: "Guilherme G. Piccoli" , linux-doc@vger.kernel.org, feng.tang@linux.alibaba.com, pmladek@suse.com, include@grrlz.net Cc: skhan@linuxfoundation.org, rdunlap@infradead.org, andriy.shevchenko@linux.intel.com, kees@kernel.org, tony.luck@intel.com, linux-kernel@vger.kernel.org, kernel-dev@igalia.com, kernel@gpiccoli.net, gpiccoli@igalia.com Subject: Re: [PATCH V2] docs: panic: Disclaimer about console verbosity when using panic_print with pstore In-Reply-To: <20260819183419.2203903-1-gpiccoli@igalia.com> References: <20260819183419.2203903-1-gpiccoli@igalia.com> Date: Mon, 24 Aug 2026 11:13:38 -0600 Message-ID: <87pkz7xwzh.fsf@trenco.lwn.net> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain "Guilherme G. Piccoli" writes: > Users of panic_print / panic_sys_info are usually aware of the potentially > huge amount of information displayed with such options - their goal by > using them is indeed to dump more information during panic! > > What might come unnoticed at first is the impact that the console_verbose() > call on panic path has, specially in cases that users rely on pstore as > a means to collect the panic logs. Recent experience shows that dumping > all tasks in an ARM64 system (with qcom_geni tty driver) gets a 2 minute > delay on panic time due to writing such information to console. But in > that case, pstore was used, so there was no need for console printing, > and suppressing that reduced the full time to less than 0.5 second. > > The option "printk.console_no_auto_verbose" aims exactly at this use > case: avoid automatically increasing the loglevel during panic path. > So, let's officially document this to avoid users wasting their time > either on long panic printing or debugging the panic delays. > > While at it, improve the readability of the panic_print text, by > adding some line breaks. > > Suggested-by: Petr Mladek > Reviewed-by: Bradley Morgan > Reviewed-by: Feng Tang > Signed-off-by: Guilherme G. Piccoli > --- > > > V2: > - Added line breaks as per Petr's suggestion (with some text improvements > as well) - thanks Petr! > > - Added review tags - thanks Feng Tang and Bradley, feel free to check > again given we added the line breaks, etc. > > V1 link: https://lore.kernel.org/r/20260805205026.1699568-1-gpiccoli@igalia.com/ > > > .../admin-guide/kernel-parameters.txt | 19 ++++++++++++++----- > 1 file changed, 14 insertions(+), 5 deletions(-) Applied, thanks. jon