Re: [PATCH v3 1/2] memcg: Prevent memcg caches to be both OFF_SLAB & OBJFREELIST_SLAB

[Andrew Morton]

On Mon, 7 Nov 2016 14:32:56 -0800 Thomas Garnier <thgarnie@xxxxxxxxxx> wrote:

> On Mon, Nov 7, 2016 at 2:19 PM, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> > On Mon,  7 Nov 2016 13:11:14 -0800 Thomas Garnier <thgarnie@xxxxxxxxxx> wrote:
> >
> >> From: Greg Thelen <gthelen@xxxxxxxxxx>
> >>
> >> While testing OBJFREELIST_SLAB integration with pagealloc, we found a
> >> bug where kmem_cache(sys) would be created with both CFLGS_OFF_SLAB &
> >> CFLGS_OBJFREELIST_SLAB.
> >>
> >> The original kmem_cache is created early making OFF_SLAB not possible.
> >> When kmem_cache(sys) is created, OFF_SLAB is possible and if pagealloc
> >> is enabled it will try to enable it first under certain conditions.
> >> Given kmem_cache(sys) reuses the original flag, you can have both flags
> >> at the same time resulting in allocation failures and odd behaviors.
> >
> > Can we please have a better description of the problems which this bug
> > causes?  Without this info it's unclear to me which kernel version(s)
> > need the fix.
> >
> > Given that the bug is 6 months old I'm assuming "not very urgent".
> >
> 
> I will add more details and send another round.

Please simply send the additional changelog text in this thread -
processing an entire v4 patch just for a changelog fiddle is rather
heavyweight.