lkml.org 
[lkml]   [2021]   [Dec]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v2 1/1] mm/vmscan.c: Prevent allocating shrinker_info on offlined nodes
On Tue 07-12-21 17:26:32, Yang Shi wrote:
> On Tue, Dec 7, 2021 at 5:23 PM Yang Shi <shy828301@gmail.com> wrote:
> >
> > On Tue, Dec 7, 2021 at 4:33 PM Nico Pache <npache@redhat.com> wrote:
> > >
> > >
> > >
> > > On 12/7/21 19:26, Yang Shi wrote:
[...]
> > > > AFAICT, we have not reached agreement on how to fix it yet. I saw 3
> > > > proposals at least:
> > > >
> > > > 1. From Michal, allocate node data for all possible nodes.
> > > > https://lore.kernel.org/all/Ya89aqij6nMwJrIZ@dhcp22.suse.cz/T/#u
> > > >
> > > > 2. What this patch does. Proposed originally from
> > > > https://lore.kernel.org/all/20211108202325.20304-1-amakhalov@vmware.com/T/#u
> > >
> > > Correct me if im wrong, but isn't that a different caller? This patch fixes the
> > > issue in expand_one_shrinker_info.
> >
> > Yes, different caller, but same approach. The cons with this approach
>
> And the same underlying problem.
>
> > is we have to fix all the places. It seems Michal and David are not
> > fans for this approach IIRC.

Yes, agreed. We definitely do not want to spread this node_offline
oddity all over the place. There are two different way to approach this.
Either we handle node_offline nodes at the page allocator level when
setting the proper zonelist (ideally protect that by a static key for
setups which have these nodes) or we allocate pgdat for all possible
nodes. I would prefer the second because that is more robust (less
likely to blow up when somebody does
for_each_node(nid)
something(NODE_DATA(nid))

The discussion is ongoing at the original thread where Alexey Makhalov
reported a similar problem (the subthread is
http://lkml.kernel.org/r/Ya89aqij6nMwJrIZ@dhcp22.suse.cz)
--
Michal Hocko
SUSE Labs

\
 
 \ /
  Last update: 2021-12-08 09:00    [W:0.038 / U:1.024 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site