From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qg0-f70.google.com (mail-qg0-f70.google.com [209.85.192.70]) by kanga.kvack.org (Postfix) with ESMTP id 6F43E8308B for ; Wed, 20 Apr 2016 23:14:29 -0400 (EDT) Received: by mail-qg0-f70.google.com with SMTP id c6so91333490qga.0 for ; Wed, 20 Apr 2016 20:14:29 -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 q77si288825qkl.244.2016.04.20.20.14.28 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 20 Apr 2016 20:14:28 -0700 (PDT) Subject: Re: linux-next crash during very early boot From: Valdis.Kletnieks@vt.edu In-Reply-To: <58269.1460729433@turing-police.cc.vt.edu> References: <3689.1460593786@turing-police.cc.vt.edu> <20160414013546.GA9198@js1304-P5Q-DELUXE> <58269.1460729433@turing-police.cc.vt.edu> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1461208466_7324P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Date: Wed, 20 Apr 2016 23:14:26 -0400 Message-ID: <18440.1461208466@turing-police.cc.vt.edu> Sender: owner-linux-mm@kvack.org List-ID: Cc: Joonsoo Kim , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org --==_Exmh_1461208466_7324P Content-Type: text/plain; charset=us-ascii On Fri, 15 Apr 2016 10:10:33 -0400, Valdis.Kletnieks@vt.edu said: > 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 will > > > 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. Following up some more - next-20160420 seems to work just fine, even with no sign in 'git log -- mm/slab.c' of the fix-patch.... I'm obviously having a very bad "things that go bump in the night" with kernels lately - this makes 3 different "makes no sense" things I've posted in the last 6 hours... :) --==_Exmh_1461208466_7324P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Exmh version 2.5 07/13/2001 iQIVAwUBVxhFkgdmEQWDXROgAQJwGw/7BV8/GM2P5HTzd9P850EWuiTLc7rjjeGQ GG3p23BjpGPZkmzMOd1BC6urNv6YH3y11umdpd76P7eK8+fiRE4DsoxFSGqRZqGX um1ccR28RnFG/1b73FjZMga+To/s85hMi0guD7rGIVmYen0xZkc6Isldk6El9rv+ YcCbs5I2ldwkIpg6fSEHcnFwWk+oyk4aPYnv0kOQZVf/RmjFBhusWZVDnQQaZpwU SAxwL9odaAuFOh6gdLUVPkqgVbZ4EpR1HOu25+zlq8D+NtUWz4tNvxp9HLO5Nmu8 hV7mXU/7ErEWFwIFr9+6kXoWS7Lz3x9iezk48CL5PpDVRjBAvukWkHDkFcX/yfne JAUCOwkd01hxoe3I9RkCHQhaswYTtVMkY4KyXXNLcQ/1qHX/DLDK/1NAxODogkjd YNuxo7Gzxhq1ZOXE28cnoeG1zDg6iPt+6I4guVLZRWzlDtCWj3MmwrSXVR2DsoJg LapolImmkHLwcYpOTpJj0znSS1jV1HYHr1gUT3xFtOFoFt/VJwJeeJ1xgnWs28gm PWH14cK8yUuCcnmJVqsNk5zp40u8tA2Viu0x3YJ+PIeYmuOusx9p8Xn4WQe/TvO8 btmXpNVGwqdCzBRrEvdEHyfYOmBEGxJyCcxYUN60LoOl2OpUwvzEwoPRmqpSY+ST GMugqoVpc7o= =5KeX -----END PGP SIGNATURE----- --==_Exmh_1461208466_7324P-- -- 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