Re: [PATCH 1/2] proc/insterrupts: make it cpu hotplug safe

[Yong Zhang]

2011/7/27 KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>:
> (2011/07/27 13:56), Yong Zhang wrote:
>> KOSAKI Motonhiro noticed that the reader of /proc/interrupts
>> could be preempted by cpu hotplug, thus the reader can get
>> broken result due to show_interrupts() iterate every online
>> cpu without any protection.
>>
>> Signed-off-by: Yong Zhang <yong.zhang0@xxxxxxxxx>
>> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
>> Cc: Keika Kobayashi <kobayashi.kk@xxxxxxxxxxxxxx>
>> Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
>> Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
>
> Looks good. but I have a question. On last thread, kobayashi-san
> suggested to use for_each_possible_cpu() and you wrote "+1".

Yeah, for_each_possible_cpu() will make code more cleaner.
so I give it my support.

>
>>> At that time, I suggested to change
>>> from for_each_online_cpu() to for_each_possible_cpu(),
>>> in /proc/interrupts.
>>+1
>>Thus we could also avoid the issue pointed by KOSAKI Motonhiro.
>
> Why do you decide to use another way?

But, as kobayashi-san has also said:
In conclusion, we decided to remain /proc/interrupts.
because it had been the way for a long time.

So I don't want to raise an argument again :)

Thanks,
Yong


-- 
Only stand for myself
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/