From: Oleg Nesterov <oleg@redhat.com>
To: Boqun Feng <boqun.feng@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
LKML <linux-kernel@vger.kernel.org>,
David Howells <dhowells@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Jonathan Corbet <corbet@lwn.net>
Subject: Re: wake_up_process implied memory barrier clarification
Date: Mon, 31 Aug 2015 20:33:35 +0200 [thread overview]
Message-ID: <20150831183335.GA26333@redhat.com> (raw)
In-Reply-To: <20150831003719.GC924@fixme-laptop.cn.ibm.com>
On 08/31, Boqun Feng wrote:
>
> Fair enough, I went too far. How about just a single paragraph saying
> that:
>
> The wake_up(), wait_event() and their friends have proper barriers in
> them, but these implicity barriers are only for the correctness for
> sleep and wakeup. So don't rely on these barriers for things that are
> neither wait-conditons nor task states.
>
> Is that OK to you?
Ask Paul ;) but personally I agree.
To me, the only thing a user should know about wake_up/try_to_wake_up
and barriers is that you do not need another barrier between setting
condition and waking up.
Oleg.
next prev parent reply other threads:[~2015-08-31 18:36 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-27 12:27 wake_up_process implied memory barrier clarification Michal Hocko
2015-08-27 12:43 ` Peter Zijlstra
2015-08-27 13:14 ` Michal Hocko
2015-08-27 18:26 ` Oleg Nesterov
2015-08-28 14:51 ` Michal Hocko
2015-08-28 16:06 ` Oleg Nesterov
2015-08-29 9:25 ` Boqun Feng
2015-08-29 14:27 ` Oleg Nesterov
2015-08-31 0:37 ` Boqun Feng
2015-08-31 18:33 ` Oleg Nesterov [this message]
2015-08-31 20:37 ` Paul E. McKenney
2015-09-01 3:40 ` Boqun Feng
2015-09-01 4:03 ` Paul E. McKenney
2015-09-01 9:59 ` Oleg Nesterov
2015-09-01 14:50 ` Boqun Feng
2015-09-01 16:39 ` Oleg Nesterov
2015-09-02 1:10 ` Boqun Feng
2015-09-07 17:06 ` Oleg Nesterov
2015-09-08 0:22 ` Boqun Feng
2015-09-01 9:41 ` Oleg Nesterov
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