On 22.02.2022 19:32, Shakeel Butt wrote:
If you are just interested in the stats, you can use SLAB for your experiments.
Unfortunately memcg_slabino.py does not support SLAB right now.
On 23.02.2022 20:31, Vlastimil Babka wrote:
On 2/23/22 04:45, Hyeonggon Yoo wrote:
On Wed, Feb 23, 2022 at 01:32:36AM +0100, Vlastimil Babka wrote:
Hm it would be easier just to disable merging when the precise counters are
enabled. Assume it would be a config option (possibly boot-time option with
static keys) anyway so those who don't need them can avoid the overhead.
Is it possible to accurately account objects in SLUB? I think it's not
easy because a CPU can free objects to remote cpu's partial slabs using
cmpxchg_double()...
AFAIU Roman's idea would be that each alloc/free would simply inc/dec an
object counter that's disconnected from physical handling of particular sl*b
implementation. It would provide exact count of objects from the perspective
of slab users.
I assume for reduced overhead the counters would be implemented in a percpu
fashion as e.g. vmstats. Slabinfo gathering would thus have to e.g. sum up
those percpu counters.
I like this idea too and I'm going to spend some time for its implementation.
Thank you,
Vasily Averin
