Re: [PATCH] ipc/msg: Implement lockless pipelined wakeups

From: Sebastian Andrzej Siewior
Date: Tue Nov 03 2015 - 09:15:35 EST


On 10/31/2015 08:06 PM, Davidlohr Bueso wrote:
> On Sat, 31 Oct 2015, Bueso wrote:
>
>> Yes, and this confirms that we still rely on the implicit barrier
>> from the cmpxchg as tglx mentioned. As such, we also need to keep
>> the pairing when reading 'r_msg' in do_msgrcv(), instead of dropping
>> the comments.
>
> Hmm having r_msg as volatile seems even less needed now, we should
> drop it. I imagine it was there initially for the busy-wait on the variable
> becoming non-nil, but we had cpu_relax _anyway_, so ...

Didn't noticed that. So that volatile part and the casts are gone, too.

Sebastian
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