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 _
