Re: [PATCH v24 00/14] Subject: Introduce Data Access MONitor (DAMON)

SeongJae Park
2021-03-04T10:10:22Z

On Thu, 4 Feb 2021 16:31:36 +0100 SeongJae Park <sjpark@amazon.com> wrote:

> From: SeongJae Park <sjpark@amazon.de>
[...]
>
> Introduction
> ============
>
> DAMON is a data access monitoring framework for the Linux kernel. The core
> mechanisms of DAMON called 'region based sampling' and 'adaptive regions
> adjustment' (refer to 'mechanisms.rst' in the 11th patch of this patchset for
> the detail) make it
>
> - accurate (The monitored information is useful for DRAM level memory
> management. It might not appropriate for Cache-level accuracy, though.),
> - light-weight (The monitoring overhead is low enough to be applied online
> while making no impact on the performance of the target workloads.), and
> - scalable (the upper-bound of the instrumentation overhead is controllable
> regardless of the size of target workloads.).
>
> Using this framework, therefore, several memory management mechanisms such as
> reclamation and THP can be optimized to aware real data access patterns.
> Experimental access pattern aware memory management optimization works that
> incurring high instrumentation overhead will be able to have another try.
>
> Though DAMON is for kernel subsystems, it can be easily exposed to the user
> space by writing a DAMON-wrapper kernel subsystem. Then, user space users who
> have some special workloads will be able to write personalized tools or
> applications for deeper understanding and specialized optimizations of their
> systems.
>
[...]
>
> Baseline and Complete Git Trees
> ===============================
>
> The patches are based on the v5.10. You can also clone the complete git
> tree:
>
> $ git clone git://github.com/sjp38/linux -b damon/patches/v24
>
> The web is also available:
> https://github.com/sjp38/linux/releases/tag/damon/patches/v24
>
> There are a couple of trees for entire DAMON patchset series. It includes
> future features. The first one[1] contains the changes for latest release,
> while the other one[2] contains the changes for next release.
>
> [1] https://github.com/sjp38/linux/tree/damon/master
> [2] https://github.com/sjp38/linux/tree/damon/next

For people who prefer LTS kernels, I decided to maintain two more trees that
repectively based on latest two LTS kernels and contains backports of the
latest 'damon/master' tree, as below. Please use those if you want to test
DAMON but using LTS.

- For v5.4.y: https://github.com/sjp38/linux/tree/damon/for-v5.4.y
- For v5.10.y: https://github.com/sjp38/linux/tree/damon/for-v5.10.y

Thanks,
SeongJae Park