Re: Still OOM problems with 4.9er/4.10er kernels

[Gerhard Wiesinger]

On 27.02.2017 09:27, Michal Hocko wrote:
> On Sun 26-02-17 09:40:42, Gerhard Wiesinger wrote:
> > On 04.01.2017 10:11, Michal Hocko wrote:
> > > > The VM stops working (e.g. not pingable) after around 8h (will be restarted
> > > > automatically), happened serveral times.
> > > >
> > > > Had also further OOMs which I sent to Mincham.
> > > Could you post them to the mailing list as well, please?
> > Still OOMs on dnf update procedure with kernel 4.10: 4.10.0-1.fc26.x86_64 as
> > well on 4.9.9-200.fc25.x86_64
> >
> > On 4.10er kernels:
> [...]
> > kernel: Node 0 DMA32 free:5012kB min:2264kB low:2828kB high:3392kB
> > active_anon:143580kB inactive_anon:143300kB active_file:2576kB
> > inactive_file:2560kB unevictable:0kB writepending:0kB present:376688kB
> > managed:353968kB mlocked:0kB slab_reclaimable:13708kB
> > slab_unreclaimable:18064kB kernel_stack:2352kB pagetables:12888kB bounce:0kB
> > free_pcp:412kB local_pcp:88kB free_cma:0kB
> [...]
>
> > On 4.9er kernels:
> [...]
> > kernel: Node 0 DMA32 free:3356kB min:2668kB low:3332kB high:3996kB
> > active_anon:122148kB inactive_anon:112068kB active_file:81324kB
> > inactive_file:101972kB unevictable:0kB writepending:4648kB present:507760kB
> > managed:484384kB mlocked:0kB slab_reclaimable:17660kB
> > slab_unreclaimable:21404kB kernel_stack:2432kB pagetables:10124kB bounce:0kB
> > free_pcp:120kB local_pcp:0kB free_cma:0kB
> In both cases the amount if free memory is above the min watermark, so
> we shouldn't be hitting the oom. We might have somebody freeing memory
> after the last attempt, though...
>
> [...]
> > Should be very easy to reproduce with a low mem VM (e.g. 192MB) under KVM
> > with ext4 and Fedora 25 and some memory load and updating the VM.
> >
> > Any further progress?
> The linux-next (resp. mmotm tree) has new tracepoints which should help
> to tell us more about what is going on here. Could you try to enable
> oom/reclaim_retry_zone and vmscan/mm_vmscan_direct_reclaim_{begin,end}

Is this available in this version?

https://koji.fedoraproject.org/koji/buildinfo?buildID=862775

kernel-4.11.0-0.rc0.git5.1.fc26

How to enable?


Thnx.

Ciao,

gerhard