From: Chen Gang <gang.chen@asianux•com>
To: Benjamin Herrenschmidt <benh@kernel•crashing.org>
Cc: chenhui.zhao@freescale•com, "paulus@samba•org" <paulus@samba•org>,
"Srivatsa S. Bhat" <srivatsa.bhat@linux•vnet.ibm.com>,
Thomas Gleixner <tglx@linutronix•de>,
"linuxppc-dev@lists•ozlabs.org" <linuxppc-dev@lists•ozlabs.org>
Subject: Re: [PATCH v2] powerpc: kernel: remove useless code which related with 'max_cpus'
Date: Thu, 25 Jul 2013 15:59:45 +0800 [thread overview]
Message-ID: <51F0DAF1.9060702@asianux.com> (raw)
In-Reply-To: <1374737592.6142.67.camel@pasglop>
On 07/25/2013 03:33 PM, Benjamin Herrenschmidt wrote:
> On Thu, 2013-07-25 at 14:17 +0800, Chen Gang wrote:
>> >
>> > Hmm... for an extern function (espeically have been implemented in
>> > various modules), normally, we can assume it may fail in some cases
>> > (although now, we don't know what cases can cause its failure).
>> >
>> > If "we don't have a good way to handle the failure", "print the related
>> > warning message" is an executable choice (or "BUG_ON()", if it is critical).
>> >
>> > So, if the performance is not sensible, I still suggest to let extern
>> > function have return value.
> This is not a module function. We are not doing a uni course on how to
> write C code here. Be real.
In our case, 'module' points to various sub directories of arch/powerpc
(maybe 'module' is not quite precise, it is easy misunderstand).
The real world is not conflict with "how to write C code".
For my opinion: one fix may like below (assume have removed max_cpus)
which is more reasonable for code readers.
-----------------------------diff begin------------------------------
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 7edbd5b..53155f4 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -347,7 +347,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
cpumask_set_cpu(boot_cpuid, cpu_core_mask(boot_cpuid));
if (smp_ops && smp_ops->probe)
- smp_ops->probe();
+ BUG_ON(smp_ops->probe() < 0);
}
void smp_prepare_boot_cpu(void)
-----------------------------diff end--------------------------------
Thanks
--
Chen Gang
next prev parent reply other threads:[~2013-07-25 8:00 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
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 [this message]
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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