From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-vk0-f72.google.com (mail-vk0-f72.google.com [209.85.213.72]) by kanga.kvack.org (Postfix) with ESMTP id C71DF6B0253 for ; Fri, 15 Apr 2016 10:10:36 -0400 (EDT) Received: by mail-vk0-f72.google.com with SMTP id h185so204561478vkg.0 for ; Fri, 15 Apr 2016 07:10:36 -0700 (PDT) Received: from omr1.cc.vt.edu (omr1.cc.ipv6.vt.edu. [2607:b400:92:8300:0:c6:2117:b0e]) by mx.google.com with ESMTPS id s66si36691347qgs.69.2016.04.15.07.10.35 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 15 Apr 2016 07:10:35 -0700 (PDT) Subject: Re: linux-next crash during very early boot From: Valdis.Kletnieks@vt.edu In-Reply-To: <20160414013546.GA9198@js1304-P5Q-DELUXE> References: <3689.1460593786@turing-police.cc.vt.edu> <20160414013546.GA9198@js1304-P5Q-DELUXE> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1460729433_2433P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Date: Fri, 15 Apr 2016 10:10:33 -0400 Message-ID: <58269.1460729433@turing-police.cc.vt.edu> Sender: owner-linux-mm@kvack.org List-ID: To: Joonsoo Kim Cc: Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org --==_Exmh_1460729433_2433P Content-Type: text/plain; charset=us-ascii On Thu, 14 Apr 2016 10:35:47 +0900, Joonsoo Kim said: > On Wed, Apr 13, 2016 at 08:29:46PM -0400, Valdis Kletnieks wrote: > > I'm seeing my laptop crash/wedge up/something during very early > > boot - before it can write anything to the console. Nothing in pstore, > > need to hold down the power button for 6 seconds and reboot. > > > > git bisect points at: > > > > commit 7a6bacb133752beacb76775797fd550417e9d3a2 > > Author: Joonsoo Kim > > Date: Thu Apr 7 13:59:39 2016 +1000 > > > > mm/slab: factor out kmem_cache_node initialization code > > > > It can be reused on other place, so factor out it. Following patch wil l > > use it. > > > > > > Not sure what the problem is - the logic *looks* ok at first read. The > > patch *does* remove a spin_lock_irq() - but I find it difficult to > > believe that with it gone, my laptop is able to hit the race condition > > the spinlock protects against *every single boot*. > > > > The only other thing I see is that n->free_limit used to be assigned > > every time, and now it's only assigned at initial creation. > > Hello, > > My fault. It should be assgined every time. Please test below patch. > I will send it with proper SOB after you confirm the problem disappear. > Thanks for report and analysis! Following up - I verified that it was your patch series and not a bad bisect by starting with a clean next-20160413 and reverting that series - and the resulting kernel boots fine. Will take a closer look at your fix patch and figure out what's still changed afterwards - there's obviously some small semantic change that actually matters, but we're not spotting it yet... --==_Exmh_1460729433_2433P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Exmh version 2.5 07/13/2001 iQIVAwUBVxD2WQdmEQWDXROgAQLtfhAAsVE1c//k3n7hQuBCdmloQxuUoG/YvvWW SKeL/vnlUpL2fKqcBdeFOMNzA8ohZ9G0ON7X3MtWDoMsbOAB1O1EnzoS75xuevW9 J0mnBk5Exog2Txn3s/cjgyxqcAfHoW/VT9q/jt40qr8uFxcFV8H9dnycnURIkCzW yTMMvwNT8TmRlwx0yTuIdA8SSOVzxj3BoOkdurf7AWMBd7oFEvYcj7mDcfieqQsI ZpS41p0l64TN7C/ahdXB9H91ogCFzLuaqFfL29GnuXdbzfNY/j3QhuD+7nCj/lT9 bPW4fr+rI/gLTFGLBtjAJv9cQopgs/OpQjpG/eWAHE9v6kn5YV88h1HcQHTyJoLS UYmuVN1o8LouJ35kTJIZXfKq7tzZDh3itQAnH9lLla9sXvMrQlech7B0Cssa2vvn Qwu6E/N/tR76YHgY7JNvIH1sjFK+eagVkDSY7rqbkWhJf8EGeVNfOqdtT/YvOPuB CxhIMbZ6/GHeHI5TIVE0RxSnnjGLlSY1MqCz/cxx1HOwgG1KtGU9HWq7t3536ujS lljpsDc9QmqS004QNgnreZJytV59fbyvW6I0upoZJiDHek8hJTI33JTnIjBfKkus 32OQsmwj3rXUyY81bSLXr4pUbDE13JVKRqzRvBFtiCl+yiaNVCUAUrAjF3gB5S+b ZQMhuKbVtJ0= =L2vc -----END PGP SIGNATURE----- --==_Exmh_1460729433_2433P-- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org