Re: ext4_alloc_context occupies 150 GiB of memory and makes the system unusable

[Ted Ts'o <tytso@mit.edu>]

Christoph,

Have you been able to replicate this problem since rebooting your
machine.  I've never seen anything quite like your report before.

If you do, a couple of questions.  Which slab allocator are you using?
Are you using SLAB or SLUB?  (grep for CONFIG_SLAB or CONFIG_SLUB in
your .config file).

If you are using SLUB, it would be useful to compile slubinfo.c (found
in /usr/src/linux/Documentation/vm/slabinfo.c) and send us the output
"slabinfo -a ext4_allocation_context" and "slabinfo -r
ext4_allocation_context".   

Also, you might try "slabinfo -s" and see if that shrinks the slabs
for you.  If this works, why it wasn't doing this automatically is
beyond me.

					- Ted