lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Tue, 21 May 2024 18:00:34 -0700
From: SeongJae Park <sj@...nel.org>
To: Jonghyeon Kim <tome01@...u.ac.kr>
Cc: SeongJae Park <sj@...nel.org>,
	damon@...ts.linux.dev,
	linux-mm@...ck.org,
	Andrew Morton <akpm@...ux-foundation.org>,
	linux-kernel@...r.kernel.org
Subject: Re: [RFC PATCH v2 0/3] Add NUMA-aware DAMOS watermarks

Hi Jonghyeon,

On Mon, 20 May 2024 14:30:35 +0000 Jonghyeon Kim <tome01@...u.ac.kr> wrote:

> Current DAMOS schemes are not considered with multiple NUMA memory nodes.
> For example, If we want to proactively reclaim memory of a one NUMA node,
> DAMON_RECLAIM has to wake up kdamond before kswapd does reclaim memory.
> However, since the DAMON watermarks are based on not a one NUMA memory
> node but total system free memory, kdamond is not waked up before invoking
> memory reclamation from kswapd of the target node.
> 
> These patches allow for DAMON to select monitoring target either total
> memory or a specific NUMA memory node.

I feel such usage could exist, but my humble brain is not clearly imagining
such realistic usage.  If you could further clarify the exampected usage, it
would be very helpful for me to better understand the intention and pros/cons
of this patchset.  Especially, I'm wondering why they would want to use the
watermark feature, rather than manually checking the metric and turning DAMON
on/off, or feeding the metric as a quota tuning goal.

> 
> ---
> Changes from RFC PATCH v1
> (https://lore.kernel.org/all/20220218102611.31895-1-tome01@ajou.ac.kr)
> - Add new metric type for NUMA node, DAMOS_WMARK_NODE_FREE_MEM_RATE
> - Drop commit about damon_start()
> - Support DAMON_LRU_SORT
> 
> Jonghyeon Kim (3):
>   mm/damon: Add new metric type and target node for watermark
>   mm/damon: add module parameters for NUMA system
>   mm/damon: add NUMA-awareness to DAMON modules

Following up to the above question, why they would want to use DAMON modules
rather than manually controlling DAMON via DAMON sysfs interface?


Thanks,
SJ

> 
>  include/linux/damon.h     | 11 +++++++++--
>  mm/damon/core.c           | 11 ++++++++---
>  mm/damon/lru_sort.c       | 14 ++++++++++++++
>  mm/damon/modules-common.h |  4 +++-
>  mm/damon/reclaim.c        | 14 ++++++++++++++
>  mm/damon/sysfs-schemes.c  | 35 +++++++++++++++++++++++++++++++++--
>  6 files changed, 81 insertions(+), 8 deletions(-)
> 
> -- 
> 2.34.1

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ