Re: [PATCH 00/12] Introduce DAMON sysfs interface

From: SeongJae Park <sj@kernel.org>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: SeongJae Park <sj@kernel.org>,
	akpm@linux-foundation.org, corbet@lwn.net,
	skhan@linuxfoundation.org, rientjes@google.com,
	xhao@linux.alibaba.com, linux-damon@amazon.com,
	linux-mm@kvack.org, linux-doc@vger.kernel.org,
	linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 00/12] Introduce DAMON sysfs interface
Date: Wed, 23 Feb 2022 16:44:40 +0000	[thread overview]
Message-ID: <20220223164440.23030-1-sj@kernel.org> (raw)
In-Reply-To: <YhZbuCcK8rW1rA6Z@kroah.com>

On Wed, 23 Feb 2022 17:07:20 +0100 Greg KH <gregkh@linuxfoundation.org> wrote:

> On Wed, Feb 23, 2022 at 03:20:39PM +0000, SeongJae Park wrote:
> > Chages from Previous Version (RFC)
> > ==================================
> > 
> > Compared to the RFC version of this patchset
> > (https://lore.kernel.org/linux-mm/20220217161938.8874-1-sj@kernel.org/), this
> > version contains below changes.
> > 
> > - Implement all DAMON debugfs interface providing features
> > - Writeup documents
> > - Add more selftests
> > 
> > Introduction
> > ============
> > 
> > DAMON's debugfs-based user interface (DAMON_DBGFS) served very well, so far.
> > However, it unnecessarily depends on debugfs, while DAMON is not aimed to be
> > used for only debugging.  Also, the interface receives multiple values via one
> > file.  For example, schemes file receives 18 values.  As a result, it is
> > inefficient, hard to be used, and difficult to be extended.  Especially,
> > keeping backward compatibility of user space tools is getting only challenging.
> > It would be better to implement another reliable and flexible interface and
> > deprecate DAMON_DBGFS in long term.
[...]
> > 
> > SeongJae Park (12):
> >   mm/damon/core: Allow non-exclusive DAMON start/stop
> >   mm/damon/core: Add number of each enum type values
> >   mm/damon: Implement a minimal stub for sysfs-based DAMON interface
> >   mm/damon/sysfs: Link DAMON for virtual address spaces monitoring
> >   mm/damon/sysfs: Support physical address space monitoring
> >   mm/damon/sysfs: Support DAMON-based Operation Schemes
> >   mm/damon/sysfs: Support DAMOS quotas
> >   mm/damon/sysfs: Support schemes prioritization weights
> >   mm/damon/sysfs: Support DAMOS watermarks
> >   mm/damon/sysfs: Support DAMOS stats
> >   selftests/damon: Add a test for DAMON sysfs interface
> >   Docs/admin-guide/mm/damon/usage: Document DAMON sysfs interface
> > 
> >  Documentation/admin-guide/mm/damon/usage.rst |  349 ++-
> >  include/linux/damon.h                        |    6 +-
> >  mm/damon/Kconfig                             |    7 +
> >  mm/damon/Makefile                            |    1 +
> >  mm/damon/core.c                              |   23 +-
> >  mm/damon/dbgfs.c                             |    2 +-
> >  mm/damon/reclaim.c                           |    2 +-
> >  mm/damon/sysfs.c                             | 2684 ++++++++++++++++++
> >  tools/testing/selftests/damon/Makefile       |    1 +
> >  tools/testing/selftests/damon/sysfs.sh       |  306 ++
> >  10 files changed, 3364 insertions(+), 17 deletions(-)
> >  create mode 100644 mm/damon/sysfs.c
> >  create mode 100755 tools/testing/selftests/damon/sysfs.sh
> 
> sysfs files need to be documented in Documentation/ABI/ which is where
> our tools look for them (have you run scripts/get_abi.pl with your code
> in the kernel?)
> 
> Please fix this up to use that format so we can then verify that you are
> using sysfs correctly.

Sure, I will do so in the next version.

Thanks,
SJ

> 
> thanks,
> 
> greg k-h