From: Peter Zijlstra <peterz@infradead.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: jkosina@suse.cz, masami.hiramatsu.pt@hitachi.com,
hpa@linux.intel.com, linux-kernel@vger.kernel.org,
x86@kernel.org
Subject: Re: [RFC][PATCH]: x86: clarify/fix no-op barriers for text_poke_bp()
Date: Mon, 31 Jul 2017 17:04:11 +0200 [thread overview]
Message-ID: <20170731150411.wff4c5qyanv7xtfy@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20170731102323.096376f5@gandalf.local.home>
On Mon, Jul 31, 2017 at 10:23:23AM -0400, Steven Rostedt wrote:
> > - smp_wmb();
>
> Heh, I think this was a "lets not leak bp_patching_in_progress" out of
> this function. But I don't see any harm if it happens.
>
> As this function was a *very* slow path, that smp_wmb() was a "it's not
> really needed, but it wont hurt anything to slap it in there just in
> case".
Well, this is x86, its a NO-OP. The only reason to write barriers like
that is for documentation purposes and in that regard is confuses. IOW
has negative value.
next prev parent reply other threads:[~2017-07-31 15:04 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-31 10:21 Peter Zijlstra
2017-07-31 14:23 ` Steven Rostedt
2017-07-31 15:04 ` Peter Zijlstra [this message]
2017-07-31 15:16 ` Steven Rostedt
2017-07-31 15:26 ` Peter Zijlstra
2017-08-01 9:12 ` Jiri Kosina
2017-08-10 16:42 ` [tip:x86/asm] x86: Clarify/fix " tip-bot for Peter Zijlstra
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