Re: Re: [PATCH v18 11/14] Documentation: Add documents for DAMON

SeongJae Park
2020-07-27T07:39:44Z

On Mon, 27 Jul 2020 00:19:00 -0700 Greg Thelen <gthelen@google.com> wrote:

> SeongJae Park <sjpark@amazon.com> wrote:
>
> > From: SeongJae Park <sjpark@amazon.de>
> >
> > This commit adds documents for DAMON under
> > `Documentation/admin-guide/mm/damon/` and `Documentation/vm/damon/`.
> >
> > Signed-off-by: SeongJae Park <sjpark@amazon.de>
> > ---
> > Documentation/admin-guide/mm/damon/guide.rst | 157 ++++++++++
> > Documentation/admin-guide/mm/damon/index.rst | 15 +
> > Documentation/admin-guide/mm/damon/plans.rst | 29 ++
> > Documentation/admin-guide/mm/damon/start.rst | 98 ++++++
> > Documentation/admin-guide/mm/damon/usage.rst | 298 +++++++++++++++++++
> > Documentation/admin-guide/mm/index.rst | 1 +
> > Documentation/vm/damon/api.rst | 20 ++
> > Documentation/vm/damon/eval.rst | 222 ++++++++++++++
> > Documentation/vm/damon/faq.rst | 59 ++++
> > Documentation/vm/damon/index.rst | 32 ++
> > Documentation/vm/damon/mechanisms.rst | 165 ++++++++++
> > Documentation/vm/index.rst | 1 +
> > 12 files changed, 1097 insertions(+)
> > create mode 100644 Documentation/admin-guide/mm/damon/guide.rst
> > create mode 100644 Documentation/admin-guide/mm/damon/index.rst
> > create mode 100644 Documentation/admin-guide/mm/damon/plans.rst
> > create mode 100644 Documentation/admin-guide/mm/damon/start.rst
> > create mode 100644 Documentation/admin-guide/mm/damon/usage.rst
> > create mode 100644 Documentation/vm/damon/api.rst
> > create mode 100644 Documentation/vm/damon/eval.rst
> > create mode 100644 Documentation/vm/damon/faq.rst
> > create mode 100644 Documentation/vm/damon/index.rst
> > create mode 100644 Documentation/vm/damon/mechanisms.rst
> >+
[...]
> > +===============
> > +Detailed Usages
> > +===============
> > +
> > +DAMON provides below three interfaces for different users.
> > +
> > +- *DAMON user space tool.*
> > + This is for privileged people such as system administrators who want a
> > + just-working human-friendly interface. Using this, users can use the DAMON’s
> > + major features in a human-friendly way. It may not be highly tuned for
> > + special cases, though. It supports only virtual address spaces monitoring.
> > +- *debugfs interface.*
> > + This is for privileged user space programmers who want more optimized use of
> > + DAMON. Using this, users can use DAMON’s major features by reading
> > + from and writing to special debugfs files. Therefore, you can write and use
> > + your personalized DAMON debugfs wrapper programs that reads/writes the
> > + debugfs files instead of you. The DAMON user space tool is also a reference
> > + implementation of such programs. It supports only virtual address spaces
> > + monitoring.
> > +- *Kernel Space Programming Interface.*
> > + This is for kernel space programmers. Using this, users can utilize every
> > + feature of DAMON most flexibly and efficiently by writing kernel space
> > + DAMON application programs for you. You can even extend DAMON for various
> > + address spaces.
> > +
> > +This document does not describe the kernel space programming interface in
> > +detail. For that, please refer to the :doc:`/vm/damon/api`.
> > +
> > +
> > +DAMON User Sapce Tool
>
> Space

Right, thanks!

>
[...]
> > +
> > +Can 'idle pages tracking' or 'perf mem' substitute DAMON?
> > +=========================================================
> > +
> > +Idle page tracking is a low level primitive for access check of the physical
> > +address space. 'perf mem' is similar, though it can use sampling to minimize
> > +the overhead. On the other hand, DAMON is a higher-level framework for the
> > +monitoring of various address spaces. It is focused on memory management
> > +optimization and provides sophisticated accuracy/overhead handling mechanisms.
> > +Therefore, 'idle pages tracking' and 'perf mem' could provide a subset of
> > +DAMON's output, but cannot substitute DAMON. Rather than that, thouse could be
>
> those?

Good eye! I will fix both in the next spin.

Thanks,
SeongJae Park