Re: [PATCH] time: add an offline-cpu check in add_timer_on()

[Andi Kleen <andi@firstfloor.org>]

Miao Xie <miaox@cn.fujitsu.com> writes:

> Hi everyone,
>   I think we need a check in the function add_timer_on() to avoid adding a
> timer into the timer list of an offline cpu.
>
> This patch fixes this problem in add_timer_on().

No it doesn't -- it will just crash if a caller does that. If it's a real 
problem then you either need to fix the callers or change add_timer_on()
to transparently put it onto another CPU.

I don't think it's a real problem though because CPU offlining does
a stop machine and that should take care of most such races.

-Andi