From mboxrd@z Thu Jan  1 00:00:00 1970
From: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Subject: Re: [PATCH v3 09/22] kthread: Allow to cancel kthread work
Date: Tue, 24 Nov 2015 15:28:55 -0500
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To: Linus Torvalds <torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
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Hello,

On Tue, Nov 24, 2015 at 12:23:53PM -0800, Linus Torvalds wrote:
> instead (possibly just "spin_unlock_wait()" - but the explicit loop

I see.  Wasn't thinking about cache traffic.  Yeah, spin_unlock_wait()
seems a lot better.

> might be worth it if you then want to check the "canceling" flag
> independently of the lock state too).
> 
> In general, it's very dangerous to try to cook up your own locking
> rules. People *always* get it wrong.

It's either trylock on timer side or timer active spinning trick on
canceling side, so this seems the lesser of the two evils.

Thanks.

-- 
tejun