Re: [PATCH v6 0/7] DAMON based tiered memory management for CXL memory

[SeongJae Park <sj@kernel.org>]

On Fri, 14 Jun 2024 12:00:02 +0900 Honggyu Kim <honggyu.kim@sk.com> wrote:

> There was an RFC IDEA "DAMOS-based Tiered-Memory Management" previously
> posted at [1].
> 
> It says there is no implementation of the demote/promote DAMOS action
> are made.  This patch series is about its implementation for physical
> address space so that this scheme can be applied in system wide level.
> 
> Changes from v5:
> https://lore.kernel.org/20240613132056.608-1-honggyu.kim@sk.com
>   1. Remove new actions in usage document as its for debugfs

Thank you, I confirmed this and gave you my Reviewed-by: tag.

>   2. Apply minor fixes on cover letter

But...

[...]
>   2. YCSB zipfian distribution read only workload (with demotion_enabled true)
>   memory pressure with cold memory on node0 with 512GB of local DRAM.
>   ====================+================================================+=========
>                       |       cold memory occupied by mmap and memset  |
>                       |   0G  440G  450G  460G  470G  480G  490G  500G |
>   ====================+================================================+=========
>   Execution time normalized to DRAM-only values                        | GEOMEAN
>   --------------------+------------------------------------------------+---------
>   DAMON tiered        |    -  1.03  1.03  1.03  1.03  1.03  1.07  1.05 | 1.04
>   DAMON lazy          |    -  1.04  1.03  1.04  1.05  1.06  1.06  1.06 | 1.05
>   DAMON tiered kswapd |    -  1.03  1.03  1.03  1.03  1.02  1.02  1.03 | 1.03
>   DAMON lazy kswapd   |    -  1.04  1.04  1.04  1.03  1.05  1.04  1.05 | 1.04
>   ====================+================================================+=========
>   CXL usage of redis-server in GB                                      | AVERAGE
>   --------------------+------------------------------------------------+---------
>   DAMON tiered        |    -   0.6   0.5   0.4   0.7   0.8   7.1   5.6 |  2.2
>   DAMON lazy          |    -   0.5   3.0   4.5   5.4   6.4   9.4   9.1 |  5.5
>   DAMON tiered kswapd |    -   0.0   0.0   0.4   0.5   0.1   0.8   1.0 |  0.4
>   DAMON lazy kswapd   |    -   4.2   4.6   5.3   1.7   6.8   8.1   5.8 |  5.2
>   ====================+================================================+=========
> 
> Each test result is based on the exeuction environment as follows.

Seems the typo is not fixed?

I don't want to delay this work for such trivial thing, though.  For the patch
series,


Acked-by: SeongJae Park <sj@kernel.org>


Thanks,
SJ

[...]