From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Fastabend Subject: Re: [PATCH net] dcbnl : Fix lock initialization Date: Thu, 06 Nov 2014 12:16:32 -0800 Message-ID: <545BD720.6050008@gmail.com> References: <1415297355-27282-1-git-send-email-anish@chelsio.com>,<545BC5F4.9070501@gmail.com> <525DB349B3FB5444AE057A887CB2A8D8935DCF@nice.asicdesigners.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: "netdev@vger.kernel.org" , "davem@davemloft.net" , "john.r.fastabend@intel.com" , "ying.xue@windriver.com" , "jeffrey.t.kirsher@intel.com" , "ebiederm@xmission.com" To: Anish Bhatt Return-path: Received: from mail-oi0-f52.google.com ([209.85.218.52]:49163 "EHLO mail-oi0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751052AbaKFUQq (ORCPT ); Thu, 6 Nov 2014 15:16:46 -0500 Received: by mail-oi0-f52.google.com with SMTP id u20so1322334oif.25 for ; Thu, 06 Nov 2014 12:16:45 -0800 (PST) In-Reply-To: <525DB349B3FB5444AE057A887CB2A8D8935DCF@nice.asicdesigners.com> Sender: netdev-owner@vger.kernel.org List-ID: On 11/06/2014 11:12 AM, Anish Bhatt wrote: > Yes, without this kernel is complaining about inconsitent lock state > when lock debugging is enabled. Unfortunately I do not have the trace > lying around right now. > If you have the trace that might help. I can't recall seeing any splats in these code paths. Also as far as I can tell you shouldn't need to do an init after the define. There are lots of examples in ./net/core where this is done. So we need to sort out why the init resolves the issue. > If you wish, you can reject this patch, I'll resend it when I get the trace again, with trace included. > -Anish > ________________________________________ > From: John Fastabend [john.fastabend@gmail.com] > Sent: Thursday, November 06, 2014 11:03 AM > To: Anish Bhatt > Cc: netdev@vger.kernel.org; davem@davemloft.net; john.r.fastabend@intel.com; ying.xue@windriver.com; jeffrey.t.kirsher@intel.com; ebiederm@xmission.com > Subject: Re: [PATCH net] dcbnl : Fix lock initialization > > On 11/06/2014 10:09 AM, Anish Bhatt wrote: >> dcb_lock was being used uninitialized in dcbnl and is infact missing >> initialization code. Fixed >> > > Are you trying to resolve a bug? It is initialized with > > static DEFINE_SPINLOCK(dcb_lock); > > and if you follow the code far enough you get to this in > spinlock_types.h: > > > #ifdef CONFIG_DEBUG_SPINLOCK > # define SPIN_DEBUG_INIT(lockname) \ > .magic = SPINLOCK_MAGIC, \ > .owner_cpu = -1, \ > .owner = SPINLOCK_OWNER_INIT, > #else > # define SPIN_DEBUG_INIT(lockname) > #endif > > #define __RAW_SPIN_LOCK_INITIALIZER(lockname) \ > { \ > .raw_lock = __ARCH_SPIN_LOCK_UNLOCKED, \ > SPIN_DEBUG_INIT(lockname) \ > SPIN_DEP_MAP_INIT(lockname) } > > [...] > > > > -- > John Fastabend Intel Corporation > -- John Fastabend Intel Corporation