From: Andrew Morton <akpm@linux-foundation.org>
To: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>, Shuah Khan <shuah@kernel.org>,
Brendan Higgins <brendanhiggins@google.com>,
David Gow <davidgow@google.com>,
damon@lists.linux.dev, linux-mm@kvack.org,
linux-doc@vger.kernel.org, kunit-dev@googlegroups.com,
linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/9] mm/damon: let users feed and tame/auto-tune DAMOS
Date: Thu, 30 Nov 2023 14:22:58 -0800 [thread overview]
Message-ID: <20231130142258.c06fcb7c0c9abd339bab5c32@linux-foundation.org> (raw)
In-Reply-To: <20231130023652.50284-1-sj@kernel.org>
On Thu, 30 Nov 2023 02:36:43 +0000 SeongJae Park <sj@kernel.org> wrote:
> The core logic uses the below simple feedback loop algorithm to
> calculate the next aggressiveness level of the scheme from the current
> aggressiveness level and the current feedback (target_score and
> current_score). It calculates the compensation for next aggressiveness
> as a proportion of current aggressiveness and distance to the target
> score. As a result, it arrives at the near-goal state in a short time
> using big steps when it's far from the goal, but avoids making
> unnecessarily radical changes that could turn out to be a bad decision
> using small steps when its near to the goal.
fwiw, the above is a "proportional controller". MGLRU has, in
vmscan.c, a PID controller (proportional, integral, derivative). PID
controllers have better accuracy (the integral feedback) and better
stability (the derivative feedback).
Generalizing MGLRU's PID controller might be somewhat challenging!
prev parent reply other threads:[~2023-11-30 22:22 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-30 2:36 [PATCH 0/9] mm/damon: let users feed and tame/auto-tune DAMOS SeongJae Park
2023-11-30 2:36 ` [PATCH 1/9] mm/damon/core: implement goal-oriented feedback-driven quota auto-tuning SeongJae Park
2023-11-30 2:36 ` [PATCH 2/9] mm/damon/sysfs-schemes: implement files for scheme quota goals setup SeongJae Park
2023-11-30 2:36 ` [PATCH 3/9] mm/damon/sysfs-schemes: commit damos quota goals user input to DAMOS SeongJae Park
2023-11-30 2:36 ` [PATCH 4/9] mm/damon/sysfs-schemes: implement a command for scheme quota goals only commit SeongJae Park
2023-11-30 2:36 ` [PATCH 5/9] mm/damon/core-test: add a unit test for the feedback loop algorithm SeongJae Park
2023-11-30 2:36 ` [PATCH 6/9] selftests/damon: test quota goals directory SeongJae Park
2023-11-30 2:36 ` [PATCH 7/9] Docs/mm/damon/design: document DAMOS quota auto tuning SeongJae Park
2023-11-30 2:36 ` [PATCH 8/9] Docs/ABI/damon: document DAMOS quota goals SeongJae Park
2023-11-30 2:36 ` [PATCH 9/9] Docs/admin-guide/mm/damon/usage: document for " SeongJae Park
2023-11-30 22:22 ` Andrew Morton [this message]
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