From: Ingo Molnar <mingo@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Will Deacon <will.deacon@arm.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Oleg Nesterov <oleg@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: Q: schedule() and implied barriers on arm64
Date: Mon, 19 Oct 2015 09:06:05 +0200 [thread overview]
Message-ID: <20151019070604.GA17855@gmail.com> (raw)
In-Reply-To: <20151016190648.GC3816@twins.programming.kicks-ass.net>
* Peter Zijlstra <peterz@infradead.org> wrote:
> In any case, its all moot now, since Paul no longer requires schedule() to imply
> a full barrier.
>
> [...]
Nevertheless from a least-surprise POV it might be worth guaranteeing it, because
I bet there's tons of code that assumes that schedule() is a heavy operation and
it's such an easy mistake to make. Since we are so close to having that guarantee,
we might as well codify it?
Just like system calls are assumed to be barriers in general - and system calls
are more lightweight than schedule() ...
Thanks,
Ingo
next prev parent reply other threads:[~2015-10-19 7:06 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-16 15:18 Q: schedule() and implied barriers on arm64 Peter Zijlstra
2015-10-16 16:04 ` Paul E. McKenney
2015-10-16 16:16 ` Peter Zijlstra
2015-10-16 16:28 ` Paul E. McKenney
2015-10-16 16:39 ` Peter Zijlstra
2015-10-16 16:55 ` Catalin Marinas
2015-10-16 17:28 ` Paul E. McKenney
2015-10-16 19:07 ` Peter Zijlstra
2015-10-16 19:20 ` Paul E. McKenney
2015-10-19 15:18 ` Catalin Marinas
2015-10-16 19:06 ` Peter Zijlstra
2015-10-19 7:06 ` Ingo Molnar [this message]
2015-10-19 9:04 ` Peter Zijlstra
2015-10-19 15:21 ` Catalin Marinas
2015-10-19 16:24 ` Peter Zijlstra
2015-10-20 8:37 ` Ingo Molnar
2015-10-27 16:19 ` Will Deacon
2015-10-27 18:40 ` Peter Zijlstra
2015-10-28 10:39 ` Will Deacon
2015-10-16 17:11 ` Catalin Marinas
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