lkml.org 
[lkml]   [2020]   [Nov]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH v22 00/18] Introduce Data Access MONitor (DAMON)
Date
Hi, I'd like to remind you that I'm still waiting more reviews.  Any comments
are welcome.


Thanks,
SeongJae Park

On Tue, 20 Oct 2020 10:59:22 +0200 SeongJae Park <sjpark@amazon.com> wrote:

> From: SeongJae Park <sjpark@amazon.de>
>
> Changes from Previous Version (v21)
> ===================================
>
> This version contains below minor changes.
>
> - Fix build warnings and errors (kernel test robot)
> - Fix a memory leak (kmemleak)
> - Respect KUNIT_ALL_TESTS
> - Rebase on v5.9
> - Update the evaluation results
>
> 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.
>
> Evaluations
> ===========
>
> We evaluated DAMON's overhead, monitoring quality and usefulness using 24
> realistic workloads on my QEMU/KVM based virtual machine running a kernel that
> v22 DAMON patchset is applied.
>
> DAMON is lightweight. It increases system memory usage by 0.25% and slows
> target workloads down by 0.89%.
>
> DAMON is accurate and useful for memory management optimizations. An
> experimental DAMON-based operation scheme for THP, 'ethp', removes 81.73% of
> THP memory overheads while preserving 95.29% of THP speedup. Another
> experimental DAMON-based 'proactive reclamation' implementation, 'prcl',
> reduces 91.30% of residential sets and 23.45% of system memory footprint while
> incurring only 2.08% runtime overhead in the best case (parsec3/freqmine).
>
> NOTE that the experimentail THP optimization and proactive reclamation are not
> for production but only for proof of concepts.
>
> Please refer to the official document[1] or "Documentation/admin-guide/mm: Add
> a document for DAMON" patch in this patchset for detailed evaluation setup and
> results.
>
> [1] https://damonitor.github.io/doc/html/latest-damon/admin-guide/mm/damon/eval.html
>

\
 
 \ /
  Last update: 2020-11-11 17:42    [W:0.224 / U:0.368 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site