Re: tools/cgroup/memcg_slabinfo.py is broken

[Roman Gushchin <guro@fb.com>]

On Tue, Feb 15, 2022 at 04:22:14PM +0300, Vasily Averin wrote:
> Dear all,
> 
> commit 07f910f9b729 ("mm: Remove slab from struct page")
> broke tools/cgroup/memcg_slabinfo.py script.
> It was used as replacement of /psys/fs/cgroup/memory/memory.kmem.slabinfo
> and was used to monitor slab objects related to specified cgroup
> 
> # ./memcg_slabinfo.py /sys/fs/cgroup/memory/lxc.payload.c9s/
> # name            <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab> : tunables <limit> <batchcount> <sharedfactor> : slabdata <active_slabs> <num_slabs> <sharedavail>
> Traceback (most recent call last):
>   File "/usr/bin/drgn", line 33, in <module>
>     sys.exit(load_entry_point('drgn==0.0.16', 'console_scripts', 'drgn')())
>   File "/usr/lib64/python3.10/site-packages/drgn/internal/cli.py", line 133, in main
>     runpy.run_path(args.script[0], init_globals=init_globals, run_name="__main__")
>   File "/usr/lib64/python3.10/runpy.py", line 269, in run_path
>     return _run_module_code(code, init_globals, run_name,
>   File "/usr/lib64/python3.10/runpy.py", line 96, in _run_module_code
>     _run_code(code, mod_globals, init_globals,
>   File "/usr/lib64/python3.10/runpy.py", line 86, in _run_code
>     exec(code, run_globals)
>   File "./memcg_slabinfo.py", line 226, in <module>
>     main()
>   File "./memcg_slabinfo.py", line 199, in main
>     cache = page.slab_cache
> AttributeError: 'struct page' has no member 'slab_cache'
> 
> Any ideas how to repair it ?
> 
> Thank you,
> 	Vasily Averin

Thanks for the report, Vasily!

I'll take a look, we need to update the script according to the latest
slab/page/folio changes.