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

From: KOSAKI Motohiro
Date: Wed Jul 27 2011 - 01:20:18 EST


(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".

>> 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?


--
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/