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Date: Fri, 5 Apr 2013 12:05:26 -0500
From: Nathan Zimmer <nzimmer@sgi.com>
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To: Al Viro <viro@ZenIV.linux.org.uk>
CC: <akpm@linux-foundation.org>, <linux-kernel@vger.kernel.org>,
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        "Eric W. Biederman" <ebiederm@xmission.com>,
        David Woodhouse <dwmw2@infradead.org>, <stable@vger.kernel.org>
Subject: Re: [PATCH resend] fs/proc: Move kfree outside pde_unload_lock
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On 04/04/2013 03:44 PM, Al Viro wrote:
> On Thu, Apr 04, 2013 at 12:12:05PM -0500, Nathan Zimmer wrote:
>
>> Ok I am cloning the tree now.
>> It does look like the patches would conflict.
>> I'll run some tests and take a deeper look.
> FWIW, I've just pushed there a tentative patch that switches to hopefully
> saner locking (head should be at cb673c115c1f99d3480471ca5d8cb3f89a1e3bee).
> Is that more or less what you want wrt spinlock contention?
>
> One note: for any given pde_opener, close_pdeo() can be called at most
> by two threads - final fput() and remove_proc_entry() resp.  I think
> the use of completion + flag is safe there; pde->pde_unload_lock
> should serialize the critical areas.

Something isn't quite right.  I keep getting hung during boot.
dracut: Mounted root filesystem /dev/sda8
dracut: Switching root

I'll try to get some more info on a smaller box.