Re: [PATCH] Hibernation: Fix lockdep report (v2)

[Pavel Machek]

On Wed 2007-11-14 22:25:57, Rafael J. Wysocki wrote:
> [Andrew, please consider this as 2.6.24 material, thanks.]
> ---
> From: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
> 
> Lockdep reports a circular locking dependency in the hibernate code
> because
>  - during system boot hibernate code (from an initcall) locks pm_mutex
>    and then a sysfs buffer mutex via name_to_dev_t
>  - during regular operation hibernate code locks pm_mutex under a
>    sysfs buffer mutex because it's called from sysfs methods.
> 
> The deadlock can never happen because during initcall invocation nothing
> can write to sysfs yet. This removes the lockdep report by marking the
> initcall locking as being in a different class.
> 
> Signed-off-by: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
> Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
> Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> Cc: Pavel Machek <pavel@xxxxxx>

ACK...

-- 
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