From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f177.google.com (mail-il1-f177.google.com [209.85.166.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 25F6A26E176 for ; Wed, 21 May 2025 13:05:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.177 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747832716; cv=none; b=M9HOlNe7ecOVhFF0pDgbqwm7SJdYVH+G7LXzWDhOmf7+7Zm5IDTDFeF87A3bk6Hse2m5KfOhleyqAjCOfp+dfBTrKxb33VLd6my6bnnHiem7d0MFcoedxR8bCdYUlzRHlFtLxlkXYVr9yFsSO4h/TCX+zj+0aW+9p1nays8lSEA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747832716; c=relaxed/simple; bh=Lfpf9KYeMfA5ceSYrwIBAnFuALvnl9+DKzgJ8mT4MWM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Um+cfWGU3kNoinOSq1DGnu/jU3cH1bIDJOJrakdSv+MmbWf4Wl9w75bQQtfc6kud6tzriT6ti9YjlFmKZAtvf9sYR+r20EWmL7sBLd1MXfqv8SC9yGLFzDipikLw7W7//A0hONx6SFAF5ghzab41r+oi0hbBRc4UmGuPlxapvwg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk; spf=pass smtp.mailfrom=kernel.dk; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b=lJv3nP45; arc=none smtp.client-ip=209.85.166.177 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kernel.dk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b="lJv3nP45" Received: by mail-il1-f177.google.com with SMTP id e9e14a558f8ab-3dc82baf4eeso3641135ab.3 for ; Wed, 21 May 2025 06:05:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20230601.gappssmtp.com; s=20230601; t=1747832711; x=1748437511; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=35BrxOOcfaPPTAO1IzcPRUrzrlbknsK0t0CSqi8oBRE=; b=lJv3nP451V3brqjdYQ0sNtrSdPfHwZaX14mdboLjHnmztxy0e3mGdA/C+Uw7jiI86n 6iz5v9aTds9+13OxdG3bxORraVKewI9IogE4r1yCTatxT9sznTqwRjt+THlxduAtuw2s Fb1VQx9EEkk2UNRw/J52NBRnY5MGGmnNANX/0MMqig2uOFOpSO+Bq2PwWQp5/yQkaAYj EG7rEQEnjgFTYg3CrPELga/DznRE6HS/cqXdQNW46R9WStFKaoZqnwGx5vJkgyIsQsxQ c2imLcg+n9S5ht8A8VLGCRLthb2hdvvq1ZtjD/GrrN7qPHN3XvUXFUKIPPyb/QfVX5Dw fX6A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1747832711; x=1748437511; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=35BrxOOcfaPPTAO1IzcPRUrzrlbknsK0t0CSqi8oBRE=; b=Fc080S1zbpzd7pD8UOW6/OvRjc7sBr7jnwznu4iHvwJyD5w3V4DAu+J4WPPWwyYwrp zwYXL7UnacrGgvVKbFIYIrRM3y78PE3TpjWEmhxSLY6EE2wISjLtYEU3uRaT1JrhJR3J A1GJc3bdx95RIcV4zyv09OSyP5pYnlnPuQwzJvt/0sSsbmYISWJLyYQ6VQFIrPv6H36A RdHdHyxAY/V4PDZiVFapW30QIs8w+aZuuIFstaYZmUjqHPEWusfvu8xhdWzXAhwJU8pn 9M7LLdEKESTe4QQYUdqyNJu4y8WR9XLBAfCWyz8mihRUlhhjpUH9rLP1/rbVL3ht2V3s RgFA== X-Forwarded-Encrypted: i=1; AJvYcCVZBhuio+1TwFB94HeDyueTRPlT7VqdzFhEXwgi3qnRbELOMLwI54mK42lb+XIJNM/BZp9wsyLx0XriZsE=@vger.kernel.org X-Gm-Message-State: AOJu0Ywjpgixx593HPAbexA0q2TH0Pavkgw41w48VGE805rHt7SK8YiT Q4zwEhw/Guydp0XjCuMhIG0oOcQbZVltnvThsl71yHTUdgXsEFwNxlzJ6SqhyyH+Az0= X-Gm-Gg: ASbGncubccpmzTXn8D/Ql6BMGK3rW3kigNvqHwL5OUqP84sid1lZ8/pr4Ih1YetozVw u8vIBA4EnyJwcIQMgzraiK8X/OyWTkyUig2snvJuOCLPEcAyteJ1HtCgeuSdi+ttlxPBHJBtaHF IzOXt5XCU/4RuN0DGpOTBbGif3rJQrl9iZpblEOTCOB/I2I3HVkVzkEzvITLNf/nDBeQVyaUPQV ueMeunmxLtaoRFLHZbIEiVfilYgn4EZWsml+k+EnBd7dErpY0WdPMoQXCehIuOQ6+W2cMI6+Gcs Q+Hb+WVdITQQ4hNTXHifHFqSOSnCnTnqMt57AV4O96g1XK0= X-Google-Smtp-Source: AGHT+IGcH4WluxWWC65gYTzjzjjMrU1aL2mLMIRkk+Pdgbz31x5IxzPpCwTODkjM4dvMG/o0xVSNlg== X-Received: by 2002:a05:6e02:3309:b0:3dc:7cc1:b74b with SMTP id e9e14a558f8ab-3dc7cc1b9e8mr62729035ab.1.1747832711001; Wed, 21 May 2025 06:05:11 -0700 (PDT) Received: from [192.168.1.116] ([96.43.243.2]) by smtp.gmail.com with ESMTPSA id e9e14a558f8ab-3db8443a37dsm28496795ab.53.2025.05.21.06.05.10 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 21 May 2025 06:05:10 -0700 (PDT) Message-ID: <0779b400-b99e-4fa2-8b18-de06fb4e77cc@kernel.dk> Date: Wed, 21 May 2025 07:05:09 -0600 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: printk NMI splat on boot To: paulmck@kernel.org Cc: John Ogness , LKML , Petr Mladek , Steven Rostedt , "senozhatsky@chromium.org" References: <84a577t590.fsf@jogness.linutronix.de> <36ccb46d-5041-47ce-b419-f49ccaeece9b@kernel.dk> Content-Language: en-US From: Jens Axboe In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/21/25 12:06 AM, Paul E. McKenney wrote: > On Tue, May 20, 2025 at 02:41:40PM -0600, Jens Axboe wrote: >> On 5/20/25 2:18 PM, Jens Axboe wrote: >>>> What values are you using for CONFIG_RCU_EXP_CPU_STALL_TIMEOUT and >>>> CONFIG_RCU_CPU_STALL_TIMEOUT? >>> >>> CONFIG_RCU_CPU_STALL_TIMEOUT=21 >>> CONFIG_RCU_EXP_CPU_STALL_TIMEOUT=2 >> >> This was =20 btw, guess it could cut a bit too much... > > Just confirming that setting CONFIG_RCU_EXP_CPU_STALL_TIMEOUT to two > milliseconds is more than a bit on the aggressive side. ;-) Sorry guess I wasn't clear - I had pasted in =2, but the setting in my config was =20. > Setting it to 20 milliseconds is OK for smartphone-class devices, but > to the best of my knowledge, setting it less than 21 seconds (as in > 21,000 milliseconds) has not been tested on any other platform. > >> Changed them to: >> >> CONFIG_RCU_CPU_STALL_TIMEOUT=100 >> CONFIG_RCU_EXP_CPU_STALL_TIMEOUT=0 >> >> and complaining is gone. > > This makes it take the default, which in this case would be the specified > CONFIG_RCU_CPU_STALL_TIMEOUT value of 100 seconds. Which is an unusually > long timeout -- mainline these days is 21 seconds and some distros still > use the old value of 60 seconds. IMHO the settings for these are very odd. Which I guess is fine for debugging kind of infrastructure, but fairly nonsensical in any case. But not really that important - looks like RCU_EXP_CPU_STALL_TIMEOUT has a default of '0' so not sure how on earth I ended up with 20 in that one. Most likely from not reading the help entry and hence setting it similarly to RCU_CPU_STALL_TIMEOUT. -- Jens Axboe