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 1BBD53EB81E for ; Tue, 17 Mar 2026 14:41:44 +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=1773758506; cv=none; b=l+Zxl3edU9ZDFqiGRwLCXo0bMv80E9YPUHR9EszR84JU38O9dnn6QNsbuAe0AqHLHyKUHP4z2Blk5cFOx8NCwptS/9TCix1pKoTddCndVaS4uQtiWId1KMaGWZISSQZQ7tlkUBTn2oiKkiOR5T79ruGlabFaOCe2ZBSAj6OFB/I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773758506; c=relaxed/simple; bh=zkCvbsdIhKl9UZnE8fSX71dB2nU9XiGjYqAANt5dRZc=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=YHWMk+ixxK/0L9iAYKEznXGf+nGeGIImaV9FLDNGR/k2AHNBFsF5RKxCI6BPnAXrEIbKCfn1PAKl/FnHDoplqemdm+s81peuPl3YJrgS58cy6w0ewEBo7RMqFID+SoSWpgBnqvvwA6BOunUj8oLOzx3JljYb7uBGg0eEqidMwRk= 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=fBYDTSxY; 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="fBYDTSxY" DKIM-Filter: OpenDKIM Filter v2.11.0 ms.lwn.net 3462040C7C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lwn.net; s=20201203; t=1773758504; bh=zkCvbsdIhKl9UZnE8fSX71dB2nU9XiGjYqAANt5dRZc=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=fBYDTSxYHvdJbQTZvcGiB3I5ZA+0xxn+e/JQ4F/3F7FftPqW9Bh/zUe68PhJVg9rv MkNY/k1YVTg5RaGyr2MxXSRhDv6fqOn35QT2ioJiROof1Z4ZlgpBOQJfhfi7S/d//i 5j4CyzOa857lOIXfR0BFPgPr9mLjL4iAWt8hq4rGNK65m07WNypX2QzeOymoZ9Uo8T e0KVONVTpz6EbyfrhuBLoSZ9KmsackpAf9vNNAdwo8EW2mJClcZt6wPzCIxeS8m3nb D3uWXoUFve2Wx0rFUShaY+GlsRiINL2HNQ0Ma7pHQSLXhfPZk3RHFuiD9nrxGVoAZP 0IQUcQbCu5pQw== Received: from localhost (c-71-229-227-126.hsd1.co.comcast.net [71.229.227.126]) (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 3462040C7C; Tue, 17 Mar 2026 14:41:44 +0000 (UTC) From: Jonathan Corbet To: John Ogness , h3288824963 <3288824963@qq.com>, linux-doc@vger.kernel.org Cc: pmladek@suse.com, senozhatsky@chromium.org, rostedt@goodmis.org, qujingling@huawei.com, zhangjiaji1@huawei.com, xushuangxing@huawei.com, hujinfei3@huawei.com, h3288824963 <3288824963@qq.com> Subject: Re: [PATCH v2] Documentation: printk: Add section about avoiding lockups In-Reply-To: <87341yd79c.fsf@jogness.linutronix.de> References: <87341yd79c.fsf@jogness.linutronix.de> Date: Tue, 17 Mar 2026 08:41:43 -0600 Message-ID: <87a4w6ecwo.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 John Ogness writes: > On 2026-03-17, h3288824963 <3288824963@qq.com> wrote: >> Add a section 'Avoiding lockups from excessive printk() use' to >> printk-basics.rst, explaining the risk of calling printk() in hot paths >> with legacy consoles and suggesting alternatives. >> >> The section covers: >> - Rate-limited and one-time printing variants >> - Log level filtering >> - printk_deferred() for legacy consoles >> - Porting to nbcon API (preferred solution) >> - Using tracepoints for permanent debugging >> >> This documentation is relevant only for legacy console drivers and >> !PREEMPT_RT kernels. >> >> Suggested-by: Petr Mladek >> Suggested-by: John Ogness >> Signed-off-by: h3288824963 <3288824963@qq.com> > > Thanks for addressing my concerns. > > Reviewed-by: John Ogness Applied, thanks. jon