From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754561AbcEPR5k (ORCPT ); Mon, 16 May 2016 13:57:40 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:34071 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753856AbcEPR5j (ORCPT ); Mon, 16 May 2016 13:57:39 -0400 Date: Mon, 16 May 2016 19:57:35 +0200 From: Peter Zijlstra To: Sedat Dilek Cc: Ingo Molnar , David Miller , Eric Dumazet , "Paul E. McKenney" , "netdev@vger.kernel.org" , the arch/x86 maintainers , LKML , Linus Torvalds Subject: Re: [v4.6-rc7-183-g1410b74e4061] Message-ID: <20160516175735.GS3193@twins.programming.kicks-ass.net> References: <20160516105045.GA19189@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 16, 2016 at 07:42:35PM +0200, Sedat Dilek wrote: > Unfortunately, I could not reproduce this again with none of my 183-kernels. > When I first hit a "chain_key collision" issue, it was hard to redproduce, so. > Any idea, how I can "force" this? Nope; I wish I knew, that'd be so much easier to work with :/ I'm hoping someone will report a reproducer, even something that triggers once every 5-10 runs would be awesome. In any case, like I've explained before, nothing regressed as such, we only added this new warning under DEBUG_LOCKDEP because we want to better understand the condition that triggers it. If it bothers you, just turn off DEBUG_LOCKDEP and know that your kernel is as reliable as it was before. OTOH, if you do keep it on, please let me know if you can (semi) reliably trigger this, as I'd really like to have a better understanding.