The patch titled Subject: Docs/mm/damon/design: document quota goal self-tuning has been added to the -mm mm-unstable branch. Its filename is docs-mm-damon-design-document-quota-goal-self-tuning.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/docs-mm-damon-design-document-quota-goal-self-tuning.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: SeongJae Park <sj@xxxxxxxxxx> Subject: Docs/mm/damon/design: document quota goal self-tuning Date: Mon, 19 Feb 2024 11:44:26 -0800 Update DAMON design doc to explain the quota goal self-tuning, which can be used by setting the goal's metric to metrics that kernel can self-retrieve. Link: https://lkml.kernel.org/r/20240219194431.159606-16-sj@xxxxxxxxxx Signed-off-by: SeongJae Park <sj@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- Documentation/mm/damon/design.rst | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) --- a/Documentation/mm/damon/design.rst~docs-mm-damon-design-document-quota-goal-self-tuning +++ a/Documentation/mm/damon/design.rst @@ -398,12 +398,28 @@ Aim-oriented Feedback-driven Auto-tuning ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Automatic feedback-driven quota tuning. Instead of setting the absolute quota -value, users can repeatedly provide numbers representing how much of their goal -for the scheme is achieved as feedback. DAMOS then automatically tunes the +value, users can specify the metric of their interest, and what target value +they want the metric value to be. DAMOS then automatically tunes the aggressiveness (the quota) of the corresponding scheme. For example, if DAMOS is under achieving the goal, DAMOS automatically increases the quota. If DAMOS is over achieving the goal, it decreases the quota. +The goal can be specified with three parameters, namely ``target_metric``, +``target_value``, and ``current_value``. The auto-tuning mechanism tries to +make ``current_value`` of ``target_metric`` be same to ``target_value``. +Currently, two ``target_metric`` are provided. + +- ``user_input``: User-provided value. Users could use any metric that they + has interest in for the value. Use space main workload's latency or + throughput, system metrics like free memory ratio or memory pressure stall + time (PSI) could be examples. Note that users should explicitly set + ``current_value`` on their own in this case. In other words, users should + repeatedly provide the feedback. +- ``some_mem_psi_us``: System-wide ``some`` memory pressure stall information + in microseconds that measured from last quota reset to next quota reset. + DAMOS does the measurement on its own, so only ``target_value`` need to be + set by users at the initial time. In other words, DAMOS does self-feedback. + .. _damon_design_damos_watermarks: _ Patches currently in -mm which might be from sj@xxxxxxxxxx are mm-damon-core-check-apply-interval-in-damon_do_apply_schemes.patch mm-damon-sysfs-schemes-handle-schemes-sysfs-dir-removal-before-commit_schemes_quota_goals.patch mm-damon-reclaim-fix-quota-stauts-loss-due-to-online-tunings.patch mm-damon-lru_sort-fix-quota-status-loss-due-to-online-tunings.patch docs-admin-guide-mm-damon-usage-use-sysfs-interface-for-tracepoints-example.patch mm-damon-rename-config_damon_dbgfs-to-damon_dbgfs_deprecated.patch mm-damon-dbgfs-implement-deprecation-notice-file.patch mm-damon-dbgfs-make-debugfs-interface-deprecation-message-a-macro.patch docs-admin-guide-mm-damon-usage-document-deprecated-file-of-damon-debugfs-interface.patch selftets-damon-prepare-for-monitor_on-file-renaming.patch mm-damon-dbgfs-rename-monitor_on-file-to-monitor_on_deprecated.patch docs-admin-guide-mm-damon-usage-update-for-monitor_on-renaming.patch docs-translations-damon-usage-update-for-monitor_on-renaming.patch mm-damon-sysfs-handle-state-file-inputs-for-every-sampling-interval-if-possible.patch selftests-damon-_damon_sysfs-support-damos-quota.patch selftests-damon-_damon_sysfs-support-damos-stats.patch selftests-damon-_damon_sysfs-support-damos-apply-interval.patch selftests-damon-add-a-test-for-damos-quota.patch selftests-damon-add-a-test-for-damos-apply-intervals.patch selftests-damon-add-a-test-for-a-race-between-target_ids_read-and-dbgfs_before_terminate.patch selftests-damon-add-a-test-for-the-pid-leak-of-dbgfs_target_ids_write.patch selftests-damon-_chk_dependency-get-debugfs-mount-point-from-proc-mounts.patch docs-mm-damon-maintainer-profile-fix-reference-links-for-mm-stable-tree.patch docs-mm-damon-move-the-list-of-damos-actions-to-design-doc.patch docs-mm-damon-move-damon-operation-sets-list-from-the-usage-to-the-design-document.patch docs-mm-damon-move-monitoring-target-regions-setup-detail-from-the-usage-to-the-design-document.patch docs-admin-guide-mm-damon-usage-fix-wrong-quotas-diabling-condition.patch mm-damon-core-set-damos_quota-esz-as-public-field-and-document.patch mm-damon-sysfs-schemes-implement-quota-effective_bytes-file.patch mm-damon-sysfs-implement-a-kdamond-command-for-updating-schemes-effective-quotas.patch docs-abi-damon-document-effective_bytes-sysfs-file.patch docs-admin-guide-mm-damon-usage-document-effective_bytes-file.patch mm-damon-move-comments-and-fields-for-damos-quota-prioritization-to-the-end.patch mm-damon-core-split-out-quota-goal-related-fields-to-a-struct.patch mm-damon-core-add-multiple-goals-per-damos_quota-and-helpers-for-those.patch mm-damon-sysfs-use-only-quota-goals.patch mm-damon-core-remove-goal-field-of-damos_quota.patch mm-damon-core-let-goal-specified-with-only-target-and-current-values.patch mm-damon-core-support-multiple-metrics-for-quota-goal.patch mm-damon-core-implement-psi-metric-damos-quota-goal.patch mm-damon-sysfs-schemes-support-psi-based-quota-auto-tune.patch docs-mm-damon-design-document-quota-goal-self-tuning.patch docs-abi-damon-document-quota-goal-metric-file.patch docs-admin-guide-mm-damon-usage-document-quota-goal-metric-file.patch mm-damon-reclaim-implement-user-feedback-driven-quota-auto-tuning.patch mm-damon-reclaim-implement-memory-psi-driven-quota-self-tuning.patch docs-admin-guide-mm-damon-reclaim-document-auto-tuning-parameters.patch