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Date: Wed, 20 Feb 2013 17:32:58 +0100
From: Borislav Petkov <bp@alien8.de>
To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
        Alessio Igor Bogani <abogani@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Chris Metcalf <cmetcalf@tilera.com>, Christoph Lameter <cl@linux.com>,
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        Gilad Ben Yossef <gilad@benyossef.com>,
        Hakan Akkan <hakanakkan@gmail.com>, Ingo Molnar <mingo@kernel.org>,
        Li Zhong <zhong@linux.vnet.ibm.com>,
        Namhyung Kim <namhyung.kim@lge.com>,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Paul Gortmaker <paul.gortmaker@windriver.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH 07/33] nohz: Basic full dynticks interface
Message-ID: <20130220163258.GB16780@pd.tnic>
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 <20130211143529.GB2749@pd.tnic>
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On Mon, Feb 11, 2013 at 03:35:29PM +0100, Borislav Petkov wrote:
> > +/* Parse the boot-time nohz CPU list from the kernel parameters. */
> > +static int __init tick_nohz_full_setup(char *str)
> > +{
> > +	alloc_bootmem_cpumask_var(&full_nohz_mask);
> > +	have_full_nohz_mask = true;
> > +	cpulist_parse(str, full_nohz_mask);
> 
> Don't you want to check retval of cpulist_parse first here before
> assigning have_full_nohz_mask and allocating cpumask var?
> 
> We don't trust userspace, you know.
> 
> > +	return 1;
> > +}
> > +__setup("full_nohz=", tick_nohz_full_setup);

One more thing. AFAICT, full_nohz requires rcu_nocbs to pass in the same
mask, right?

Maybe tick_nohz_full_setup() could be made to call rcu_nocb_setup()
without the need to pass "rcu_nocbs=" option on the cmd line; in the
sense that if user supplies a full_nohz mask, she wants the same mask
for rcu_nocbs...

Thanks.

-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
--