From: Chen Gang <gang.chen@asianux•com>
To: "Srivatsa S. Bhat" <srivatsa.bhat@linux•vnet.ibm.com>
Cc: chenhui.zhao@freescale•com, "paulus@samba•org" <paulus@samba•org>,
Thomas Gleixner <tglx@linutronix•de>,
"linuxppc-dev@lists•ozlabs.org" <linuxppc-dev@lists•ozlabs.org>
Subject: Re: [PATCH] powerpc: kernel: remove useless code which related with 'max_cpus'
Date: Mon, 22 Jul 2013 14:27:11 +0800 [thread overview]
Message-ID: <51ECD0BF.8080605@asianux.com> (raw)
In-Reply-To: <51ECCEA8.5040406@linux.vnet.ibm.com>
On 07/22/2013 02:18 PM, Srivatsa S. Bhat wrote:
> On 07/22/2013 11:28 AM, Chen Gang wrote:
>> > Since not need 'max_cpus' after the related commit, the related code
>> > are useless too, need be removed.
>> >
>> > The related commit:
>> >
>> > c1aa687 powerpc: Clean up obsolete code relating to decrementer and timebase
>> >
>> > The related warning:
>> >
>> > arch/powerpc/kernel/smp.c:323:43: warning: parameter �max_cpus� set but not used [-Wunused-but-set-parameter]
>> >
>> > Signed-off-by: Chen Gang <gang.chen@asianux•com>
>> > ---
>> > arch/powerpc/kernel/smp.c | 8 --------
>> > 1 files changed, 0 insertions(+), 8 deletions(-)
>> >
>> > diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
>> > index 38b0ba6..8c2bae4 100644
>> > --- a/arch/powerpc/kernel/smp.c
>> > +++ b/arch/powerpc/kernel/smp.c
>> > @@ -345,14 +345,6 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
>> >
>> > cpumask_set_cpu(boot_cpuid, cpu_sibling_mask(boot_cpuid));
>> > cpumask_set_cpu(boot_cpuid, cpu_core_mask(boot_cpuid));
>> > -
>> > - if (smp_ops)
>> > - if (smp_ops->probe)
>> > - max_cpus = smp_ops->probe();
> No, you can't just remove the call to ->probe(). Its essential.
> For example, one such ->probe() routine, xics_smp_probe() does some
> pretty important stuff, such as populating the ->cause_ipi function
> pointer etc, see below:
>
> 143 int __init xics_smp_probe(void)
> 144 {
> 145 /* Setup cause_ipi callback based on which ICP is used */
> 146 smp_ops->cause_ipi = icp_ops->cause_ipi;
> 147
> 148 /* Register all the IPIs */
> 149 xics_request_ipi();
> 150
> 151 return cpumask_weight(cpu_possible_mask);
> 152 }
>
OK, thanks.
>> > - else
>> > - max_cpus = NR_CPUS;
>> > - else
>> > - max_cpus = 1;
>> > }
>> >
> Yes, max_cpus is unused, but you have to be careful while removing
> code.
I should send patch v2, soon. :-)
> Regards,
> Srivatsa S. Bhat
>
>
>
Thanks.
--
Chen Gang
next prev parent reply other threads:[~2013-07-22 6:28 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-22 5:58 [PATCH] powerpc: kernel: remove useless code which related with 'max_cpus' Chen Gang
2013-07-22 6:18 ` Srivatsa S. Bhat
2013-07-22 6:27 ` Chen Gang [this message]
2013-07-22 6:40 ` [PATCH v2] " Chen Gang
2013-07-22 6:51 ` Srivatsa S. Bhat
2013-07-22 7:03 ` Chen Gang
2013-07-23 13:44 ` Michael Ellerman
2013-07-24 0:28 ` Chen Gang
2013-07-24 1:16 ` Michael Ellerman
2013-07-24 2:09 ` Chen Gang
2013-07-25 3:15 ` Michael Ellerman
2013-07-25 4:02 ` Chen Gang
2013-07-25 5:16 ` Benjamin Herrenschmidt
2013-07-25 5:24 ` Chen Gang
2013-07-25 5:51 ` Benjamin Herrenschmidt
2013-07-25 6:03 ` Benjamin Herrenschmidt
2013-07-25 6:30 ` Chen Gang
2013-07-25 6:17 ` Chen Gang
2013-07-25 7:33 ` Benjamin Herrenschmidt
2013-07-25 7:59 ` Chen Gang
2013-07-25 8:06 ` Benjamin Herrenschmidt
2013-07-25 8:22 ` Chen Gang
2013-07-25 8:28 ` Benjamin Herrenschmidt
2013-07-25 8:36 ` Chen Gang
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