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Date: Tue, 12 Nov 2013 17:41:47 +0800
From: Fengguang Wu <fengguang.wu@intel.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>, Ingo Molnar <mingo@kernel.org>,
        linux-kernel@vger.kernel.org, Vivek Goyal <vgoyal@redhat.com>,
        Jens Axboe <axboe@kernel.dk>
Subject: Re: [seqcount] INFO: trying to register non-static key.
Message-ID: <20131112094147.GA32441@localhost>
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On Mon, Nov 11, 2013 at 04:45:51PM +0100, Peter Zijlstra wrote:
> On Mon, Nov 11, 2013 at 09:29:27AM +0800, Fengguang Wu wrote:
> > Greetings,
> > 
> > I got the below dmesg and the first bad commit is
> > 
> > commit 1ca7d67cf5d5a2aef26a8d9afd789006fa098347
> > Author: John Stultz <john.stultz@linaro.org>
> > Date:   Mon Oct 7 15:51:59 2013 -0700
> > 
> >     seqcount: Add lockdep functionality to seqcount/seqlock structures
> >
> 
> > [    4.124336] uli526x: ULi M5261/M5263 net driver, version 0.9.3 (2005-7-29)
> > [    4.128027] Call Trace:
> > [    4.128027]  [<7908e744>] ? console_unlock+0x353/0x380
> > [    4.128027]  [<79dc7cf2>] dump_stack+0x48/0x60
> > [    4.128027]  [<7908953e>] __lock_acquire.isra.26+0x7e3/0xceb
> > [    4.128027]  [<7908a1c5>] lock_acquire+0x71/0x9a
> > [    4.128027]  [<794079aa>] ? blk_throtl_bio+0x1c3/0x485
> > [    4.128027]  [<7940658b>] throtl_update_dispatch_stats+0x7c/0x153
> 
> The below seems to compile with i386-defconfig + CONFIG_CFQ_GROUP_IOSCHED=y
> 
> No idea if it runs properly or not; I seem to have misplaced my i386
> root filesystem.
> 
> ---
> Subject: block: Employ u64_stats_init()
> 
> Now that seqcounts are lockdep tracked thingies, we need to properly
> initialize them, otherwise bad stuff happens.

FYI the warning is still there:

/kernel/i386-randconfig-j7-11082318/d3516a7318f8e22f5462888fdf9edc8f0f128024

+-------------------------------------------------+-------+--------------+--------------+
|                                                 | v3.12 | 838cc7b488f8 | d3516a7318f8 |
+-------------------------------------------------+-------+--------------+--------------+
| boot_successes                                  | 129   | 0            | 0            |
| boot_failures                                   | 1     | 100          | 100          |
| BUG:kernel_early_hang_without_any_printk_output | 1     |              |              |
| INFO:trying_to_register_non-static_key          | 0     | 100          | 100          |
+-------------------------------------------------+-------+--------------+--------------+

Thanks,
Fengguang