From: Davidlohr Bueso <dave@stgolabs.net>
To: George Spelvin <linux@horizon.com>
Cc: bigeasy@linutronix.de, tglx@linutronix.de,
akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
manfred@colorfullife.com, peterz@infradead.org
Subject: Re: [PATCH] ipc/msg: Implement lockless pipelined wakeups
Date: Sat, 31 Oct 2015 12:06:33 -0700 [thread overview]
Message-ID: <20151031190633.GA1707@linux-uzut.site> (raw)
In-Reply-To: <20151031185457.GC7947@linux-uzut.site>
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 ...
next prev parent reply other threads:[~2015-10-31 19:06 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-30 11:26 [PATCH] ipc/msg: Implement lockless pipelined wakeups Sebastian Andrzej Siewior
2015-10-30 22:30 ` George Spelvin
2015-11-03 14:01 ` Sebastian Andrzej Siewior
2015-10-31 10:31 ` Thomas Gleixner
2015-10-31 13:02 ` George Spelvin
2015-10-31 15:17 ` Thomas Gleixner
2015-10-31 18:54 ` Davidlohr Bueso
2015-10-31 19:06 ` Davidlohr Bueso [this message]
2015-11-03 14:15 ` Sebastian Andrzej Siewior
2015-11-03 14:11 ` Sebastian Andrzej Siewior
2015-11-01 4:32 ` Manfred Spraul
2015-11-03 14:51 ` Sebastian Andrzej Siewior
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