[PATCH] thermal: Add missing cpumask_clear
Tomasz Figa
tomasz.figa at gmail.com
Fri Jul 4 17:34:07 PDT 2014
Hi Jonghwan,
On 05.07.2014 01:37, Jonghwan Choi wrote:
> On Fri, Jul 4, 2014 at 8:23 PM, Sachin Kamat <spk.linux at gmail.com> wrote:
>
>>> Cpumasks should be cleared before using.
>>
>> Please explain why and what is issue observed without this.
>>
>
> -> When I checked the mask value, I knew that unwanted bit is set.
>
> Test code without cpumask_clear.
>
> + cpumask_set_cpu(0, &mask_val);
> + cpulist_scnprintf(buf, 64, &mask_val);
> + printk("--ID [ %d] = %s \n", id, buf);
> + th_zone->cool_dev[id] = cpufreq_cooling_register(&mask_val);
>
>
> Console message-> 4.861157] [c6] --ID [ 1] = 0,4-5,7 (4,5,7 cpu bit was set.)
>
> And when I tried to register two cooling devices with cpumask_set_cpu(0, &mask_val) and cpumask_set_cpu(4, &mask_val).
>
> I found that cpu 0 bit is also set in latter cpumask. (I hope latter cpumask has a cpu 4 bit.)
>
> So I think that cpumask_clear should be inserted.
I believe Sachin's concern was related to your patch description. A good
description should say what the patch changes and what is the rationale
behind this change. Also for fixes it is a good practice to specify
observed issues in patch description as well.
Best regards,
Tomasz
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