2020년 7월 24일 (금) 오후 12:14, Andrew Morton <a...@linux-foundation.org>님이 작성:
>
> On Fri, 24 Jul 2020 12:04:02 +0900 Joonsoo Kim <js1...@gmail.com> wrote:
>
> > 2020년 7월 24일 (금) 오전 11:36, Andrew Morton <a...@linux-foundation.org>님이 작성:
> > >
> > > On Fri, 24 Jul 2020 11:23:52 +0900 Joonsoo Kim <js1...@gmail.com> wrote:
> > >
> > > > > > Second, clearing __GFP_MOVABLE in current_gfp_context() has a side
> > > > > > effect
> > > > > > to exclude the memory on the ZONE_MOVABLE for allocation target.
> > > > >
> > > > > More whoops.
> > > > >
> > > > > Could we please have a description of the end-user-visible effects of
> > > > > this change? Very much needed when proposing a -stable backport, I
> > > > > think.
> > > >
> > > > In fact, there is no noticeable end-user-visible effect since the
> > > > fallback would
> > > > cover the problematic case. It's mentioned in the commit description.
> > > > Perhap,
> > > > performance would be improved due to reduced retry and more available
> > > > memory
> > > > (we can use ZONE_MOVABLE with this patch) but it would be neglectable.
> > > >
> > > > > d7fefcc8de9147c is over a year old. Why did we only just discover
> > > > > this? This makes one wonder how serious those end-user-visible
> > > > > effects
> > > > > are?
> > > >
> > > > As mentioned above, there is no visible problem to the end-user.
> > >
> > > OK, thanks. In that case, I don't believe that a stable backport is
> > > appropriate?
> > >
> > > (Documentation/process/stable-kernel-rules.rst)
> >
> > Thanks for the pointer!
> >
> > Hmm... I'm not sure the correct way to handle this patch. I thought that
> > memalloc_nocma_{save,restore} is an API that is callable from the module.
> > If it is true, it's better to regard this patch as the stable candidate
> > since
> > out-of-tree modules could use it without the fallback and it would cause
> > a problem. But, yes, there is no visible problem to the end-user, at least,
> > within the mainline so it is possibly not a stable candidate.
> >
> > Please share your opinion about this situation.
>
> We tend not to care much about out-of-tree modules. I don't think a
> theoretical concern for out-of-tree code justifies risking the
> stability of -stable kernels.
Okay. It's appreciated if you remove the stable tag. Or, I will send it again
without the stable tag.
Thanks.
