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From: Peter Zijlstra <peterz@infradead.org>
To: Ingo Molnar <mingo@elte.hu>
Cc: Frederic Weisbecker <fweisbec@gmail.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Arnaldo Carvalho de Melo <acme@redhat.com>,
	Paul Mackerras <paulus@samba.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Masami Hiramatsu <mhiramat@redhat.com>,
	Jason Baron <jbaron@redhat.com>
Subject: Re: [PATCH 1/4] tracing: Use the perf recursion protection from trace event
Date: Sun, 22 Nov 2009 12:24:53 +0100	[thread overview]
Message-ID: <1258889093.28730.380.camel@laptop> (raw)
In-Reply-To: <20091122112259.GA24741@elte.hu>

On Sun, 2009-11-22 at 12:22 +0100, Ingo Molnar wrote:

> > > +void perf_swevent_put_recursion_context(int *recursion)
> > >  {
> > > -       struct perf_cpu_context *cpuctx = &get_cpu_var(perf_cpu_context);
> > > -       int *recursion = perf_swevent_recursion_context(cpuctx);
> > > -       struct perf_event_context *ctx;
> > > -
> > > -       if (*recursion)
> > > -               goto out;
> > > +       (*recursion)--;
> > > +}
> > 
> > And here as well.
> 
> Global functions are in essence a barrier() to GCC but yeah.

Can't rely on that, because if the thing decides to inline this function
it looses that barrier semantic.

And it being such a small function with a few callsites in the same
translation unit, there's a fair chance it will actually inline.


  reply	other threads:[~2009-11-22 11:25 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-11-22  4:21 [PATCH 1/4] tracing: Use the perf recursion protection from trace event Frederic Weisbecker
2009-11-22  4:21 ` [PATCH 2/4] tracing: Forget about the nmi buffer from syscall events Frederic Weisbecker
2009-11-22  8:43   ` [tip:perf/core] tracing: Forget about the NMI buffer for " tip-bot for Frederic Weisbecker
2009-11-22  4:21 ` [PATCH 3/4] hw-breakpoints: Remove x86 specific headers from core file Frederic Weisbecker
2009-11-22  8:43   ` [tip:perf/core] " tip-bot for Frederic Weisbecker
2009-11-22  4:21 ` [PATCH 4/4] hw-breakpoints: Separate the kernel part from breakpoint headers Frederic Weisbecker
2009-11-22  8:43   ` [tip:perf/core] " tip-bot for Frederic Weisbecker
2009-11-22  4:26 ` [PATCH 1/4 v2] tracing: Use the perf recursion protection from trace event Frederic Weisbecker
2009-11-22  8:42   ` [tip:perf/core] " tip-bot for Frederic Weisbecker
2009-11-22 11:24   ` [tip:perf/core] perf_events: Fix modular build tip-bot for Ingo Molnar
2009-11-22 11:00 ` [PATCH 1/4] tracing: Use the perf recursion protection from trace event Peter Zijlstra
2009-11-22 11:22   ` Ingo Molnar
2009-11-22 11:24     ` Peter Zijlstra [this message]
2009-11-22 16:37   ` Frederic Weisbecker
2009-11-22 16:50     ` Peter Zijlstra

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