Re: [PATCH] Documentation: Remove misleading examples of the barriers in wake_*()

From: Peter Zijlstra <peterz@infradead.org>
To: Boqun Feng <boqun.feng@gmail.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
	Oleg Nesterov <oleg@redhat.com>,
	linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
	Jonathan Corbet <corbet@lwn.net>,
	Michal Hocko <mhocko@kernel.org>,
	David Howells <dhowells@redhat.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Will Deacon <will.deacon@arm.com>
Subject: Re: [PATCH] Documentation: Remove misleading examples of the barriers in wake_*()
Date: Mon, 12 Oct 2015 13:54:38 +0200	[thread overview]
Message-ID: <20151012115438.GM3816@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <20151012090636.GF27351@fixme-laptop.cn.ibm.com>

On Mon, Oct 12, 2015 at 05:06:36PM +0800, Boqun Feng wrote:
> Understood.
> 
> But, IMO, the position of this section is already misleading:
> 
> (*) Implicit kernel memory barriers.
>      - Locking functions.
>      - Interrupt disabling functions.
>    ->- Sleep and wake-up functions.<-
>      - Miscellaneous functions.
> 
> I read it as that sleep and wake-up functions provide some kernel memory
> barriers which we can use *externally*(outside sleep/wakeup themselves).

I think it is useful to state that the primitives handle the ordering
between the waker and wakee wrt the 'blocking' state.

But I've not put much thought into wording. I wanted to finish process
order 'comment' patch first.