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SubjectRe: [patch V4 02/10] rtmutex: Simplify rtmutex_slowtrylock()
On 06/12/2014 02:44 AM, Thomas Gleixner wrote:
> Oleg noticed that rtmutex_slowtrylock() has a pointless check for
> rt_mutex_owner(lock) != current.
>
> To avoid calling try_to_take_rtmutex() we really want to check whether
> the lock has an owner at all or whether the trylock failed because the
> owner is NULL, but the RT_MUTEX_HAS_WAITERS bit is set. This covers
> the lock is owned by caller situation as well.
>
> We can actually do this check lockless. trylock is taking a chance
> whether we take lock->wait_lock to do the check or not.
>
> Add comments to the function while at it.
>
> Reported-by: Oleg Nesterov <oleg@redhat.com>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> ---

Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>

Thanks,
Lai


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