Re: Slab Unreclaimable is continually growing

[Shahryar Afifi <shahryarafifi@yahoo.com>]

What happens  when you run sync in terminal? 



On Wed, 2019-07-24 at 18:54 +0200, Matthias B??ttcher wrote:
> Hi list,
> 
> my buster is using more and more memory until the oom-killer is
> invoked. This occurs after two days of uptime, but no process is
> using
> that memory. Slab seems suspicious to me.
> 
> Kernel: 4.19.37-5+deb10u1 (2019-07-19) x86_64
> 
> from /proc/meminfo after 8 hours uptime:
> 
> MemTotal:        4041116 kB
> MemFree:         3165992 kB
> MemAvailable:    3246560 kB
> Buffers:           30144 kB
> Cached:           240356 kB
> SwapCached:            0 kB
> Active:           162056 kB
> Inactive:         144268 kB
> SwapTotal:       4194300 kB
> SwapFree:        4194300 kB
> 
> Slab:             521364 kB
> SReclaimable:      66776 kB
> SUnreclaim:       454588 kB
> 
> My Top 5 in slabtop:
> 
> $ sudo slabtop --sort c --once | head -n12
> 
>  Active / Total Objects (% used)    : 2234301 / 2270100 (98,4%)
>  Active / Total Slabs (% used)      : 70832 / 70832 (100,0%)
>  Active / Total Caches (% used)     : 98 / 124 (79,0%)
>  Active / Total Size (% used)       : 501034,52K / 509459,17K (98,3%)
>  Minimum / Average / Maximum Object : 0,01K / 0,22K / 8,00K
> 
>   OBJS ACTIVE  USE OBJ SIZE  SLABS OBJ/SLAB CACHE SIZE NAME
> 307534 304741  99%    0,20K  16186       19     64744K vm_area_struct
>  14280  14274  99%    3,69K   1785        8     57120K task_struct
> 178048 152224  85%    0,25K  11128       16     44512K filp
>   8536   8536 100%    4,00K   1067        8     34144K kmalloc-4096
>  14640  14640 100%    2,06K    976       15     31232K sighand_cache
> 
> Active / Total Size is growing continually about 60 MB per hour.
> 
> How can I detect what is eating up my memory in SUnreclaim (slab
> unreclaimable)?
> 
> Thanks in advance
> Matthias B??ttcher
>