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

[Michal Hocko]

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?

-- 
Michal Hocko
SUSE Labs