Re: A udev rule to serve the change event of ACPI container?

Date: Thu Aug 03 2017 - 11:37:47 EST

On 08/02/2017 01:49 AM, joeyli wrote:
> On Tue, Aug 01, 2017 at 03:21:38PM -0400, YASUAKI ISHIMATSU wrote:
>> Hi Joey,
>> On 07/23/2017 05:18 AM, joeyli wrote:
> [...snip]
>>>> At least Yasuaki raised similar behavior for container in 2013.
>>>> It's similar to the DVD player case, user space application needs
>>>> to do something then trigger children offline and ejection of
>>>> container.
>>>> Base on Yasuaki's explanation, the reason of that he requested the
>>>> userland ejection approach is that he got memory hot-remove problem
>>>> in 2013. Maybe his problem is already fixed by your patches in current
>>>> mainline.
>>>> Hi Yasuaki, could you please check that your memory hot-remove problem
>>>> is fixed on mainline kernel?
>> I cannot remember what I mentioned in 2013. Could you tell me url of lkml archive.

> Here:

Thank you for specifying the URL. In the URL, I wrote the following problems:

> 1. easily fail
> My container device has CPU device and Memory device, and maximum size of
> memory is 3Tbyte. In my environment, hot removing container device fails
> on offlining memory if memory is used by application.
> I think if offlininig memory, we must retly to offline memory several
> times.

I think the issue still remains. If process keeps accessing memory, offlining
the memory easily fails with EBUSY.

Yasuaki Ishimatsu

> In the mail, you mentioned two problems. But there have no detail about
> those issues, and no root causes. We don't know why kernel should relies
> on user space to complete the hot removing process for container.
> Thank a lot!
> Joey Lee