Re: [PATCH 2/2] mm, memory_hotplug: remove timeout from __offline_memory

[Xishi Qiu]

On 2017/9/4 17:01, Michal Hocko wrote:

> On Mon 04-09-17 16:58:30, Xishi Qiu wrote:
>> On 2017/9/4 16:21, Michal Hocko wrote:
>>
>>> From: Michal Hocko <mhocko@xxxxxxxx>
>>>
>>> We have a hardcoded 120s timeout after which the memory offline fails
>>> basically since the hot remove has been introduced. This is essentially
>>> a policy implemented in the kernel. Moreover there is no way to adjust
>>> the timeout and so we are sometimes facing memory offline failures if
>>> the system is under a heavy memory pressure or very intensive CPU
>>> workload on large machines.
>>>
>>> It is not very clear what purpose the timeout actually serves. The
>>> offline operation is interruptible by a signal so if userspace wants
>>
>> Hi Michal,
>>
>> If the user know what he should do if migration for a long time,
>> it is OK, but I don't think all the users know this operation
>> (e.g. ctrl + c) and the affect.
> 
> How is this operation any different from other potentially long
> interruptible syscalls?
> 

Hi Michal,

I means the user should stop it by himself if migration always retry in endless.

Thanks,
Xishi Qiu