From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f199.google.com (mail-pf0-f199.google.com [209.85.192.199]) by kanga.kvack.org (Postfix) with ESMTP id 536A96B0261 for ; Wed, 20 Apr 2016 04:10:31 -0400 (EDT) Received: by mail-pf0-f199.google.com with SMTP id u190so74244870pfb.0 for ; Wed, 20 Apr 2016 01:10:31 -0700 (PDT) Received: from lgeamrelo13.lge.com (LGEAMRELO13.lge.com. [156.147.23.53]) by mx.google.com with ESMTP id u184si4209166pfu.78.2016.04.20.01.10.29 for ; Wed, 20 Apr 2016 01:10:30 -0700 (PDT) Date: Wed, 20 Apr 2016 17:13:45 +0900 From: Joonsoo Kim Subject: Re: linux-next crash during very early boot Message-ID: <20160420081345.GC7071@js1304-P5Q-DELUXE> 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: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <58269.1460729433@turing-police.cc.vt.edu> Sender: owner-linux-mm@kvack.org List-ID: To: Valdis.Kletnieks@vt.edu Cc: Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org On Fri, Apr 15, 2016 at 10:10:33AM -0400, Valdis.Kletnieks@vt.edu wrote: > 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... Hello, Do you try to test the patch in following link on top of my fix for "mm/slab: factor out kmem_cache_node initialization code"? https://lkml.org/lkml/2016/4/10/703 I mentioned it in another thread but you didn't reply it so I'm curious. Thanks. -- 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