The patch titled Subject: Docs/vm/damon/design: update DAMON-Idle Page Tracking interference handling has been added to the -mm tree. Its filename is docs-vm-damon-design-update-damon-idle-page-tracking-interference-handling.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/docs-vm-damon-design-update-damon-idle-page-tracking-interference-handling.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/docs-vm-damon-design-update-damon-idle-page-tracking-interference-handling.patch 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 and is updated there every 3-4 working days ------------------------------------------------------ From: SeongJae Park <sj@xxxxxxxxxx> Subject: Docs/vm/damon/design: update DAMON-Idle Page Tracking interference handling In DAMON's early development stage before it be merged in the mainline, it was first designed to work exclusively with Idle page tracking to avoid any interference between each other. Later, but still before be merged in the mainline, because Idle page tracking is fully under the control of sysadmins, we made the resolving of conflict as the responsibility of sysadmins. The document is not updated for the change, though. This commit updates the document for that. Link: https://lkml.kernel.org/r/20220222170100.17068-3-sj@xxxxxxxxxx Signed-off-by: SeongJae Park <sj@xxxxxxxxxx> Cc: Jonathan Corbet <corbet@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- Documentation/vm/damon/design.rst | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/Documentation/vm/damon/design.rst~docs-vm-damon-design-update-damon-idle-page-tracking-interference-handling +++ a/Documentation/vm/damon/design.rst @@ -84,9 +84,10 @@ table having a mapping to the address. and clear the bit(s) for next sampling target address and checks whether the bit(s) set again after one sampling period. This could disturb other kernel subsystems using the Accessed bits, namely Idle page tracking and the reclaim -logic. To avoid such disturbances, DAMON makes it mutually exclusive with Idle -page tracking and uses ``PG_idle`` and ``PG_young`` page flags to solve the -conflict with the reclaim logic, as Idle page tracking does. +logic. DAMON does nothing to avoid disturbing Idle page tracking, so handling +the interference is the responsibility of sysadmins. However, it solves the +conflict with the reclaim logic using ``PG_idle`` and ``PG_young`` page flags, +as Idle page tracking does. Address Space Independent Core Mechanisms _ Patches currently in -mm which might be from sj@xxxxxxxxxx are mm-damon-dbgfs-init_regions-use-target-index-instead-of-target-id.patch docs-admin-guide-mm-damon-usage-update-for-changed-initail_regions-file-input.patch mm-damon-core-move-damon_set_targets-into-dbgfs.patch mm-damon-remove-the-target-id-concept.patch mm-damon-rename-damon_primitives-to-damon_operations.patch mm-damon-let-monitoring-operations-can-be-registered-and-selected.patch mm-damon-paddrvaddr-register-themselves-to-damon-in-subsys_initcall.patch mm-damon-reclaim-use-damon_select_ops-instead-of-damon_vpa_set_operations.patch mm-damon-dbgfs-use-damon_select_ops-instead-of-damon_vpa_set_operations.patch mm-damon-dbgfs-use-operations-id-for-knowing-if-the-target-has-pid.patch mm-damon-dbgfs-test-fix-is_target_id-change.patch mm-damon-paddrvaddr-remove-damon_pva_target_validset_operations.patch docs-vm-damon-call-low-level-monitoring-primitives-the-operations.patch docs-vm-damon-design-update-damon-idle-page-tracking-interference-handling.patch docs-damon-update-outdated-term-regions-update-interval.patch