kernel.git/samples/damon/mtier.c, branch linux-6.16.y

samples/damon/mtier: avoid starting DAMON before initialization

2025-09-25T09:16:54Z

[ Upstream commit c62cff40481c037307a13becbda795f7afdcfebd ] Commit 964314344eab ("samples/damon/mtier: support boot time enable setup") is somehow incompletely applying the origin patch [1]. It is missing the part that avoids starting DAMON before module initialization. Probably a mistake during a merge has happened. Fix it by applying the missed part again. Link: https://lkml.kernel.org/r/20250909022238.2989-4-sj@kernel.org Link: https://lore.kernel.org/20250706193207.39810-4-sj@kernel.org [1] Fixes: 964314344eab ("samples/damon/mtier: support boot time enable setup") Signed-off-by: SeongJae Park Cc: Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

samples/damon: change enable parameters to enabled

2025-09-25T09:16:54Z

[ Upstream commit 793020545cea0c9e2a79de6ad5c9746ec4f5bd7e ] The damon_{lru_sort,reclaim,stat} kernel modules use "enabled" parameter knobs as follows. /sys/module/damon_lru_sort/parameters/enabled /sys/module/damon_reclaim/parameters/enabled /sys/module/damon_stat/parameters/enabled However, other sample modules of damon use "enable" parameter knobs so it'd be better to rename them from "enable" to "enabled" to keep the consistency with other damon modules. Before: /sys/module/damon_sample_wsse/parameters/enable /sys/module/damon_sample_prcl/parameters/enable /sys/module/damon_sample_mtier/parameters/enable After: /sys/module/damon_sample_wsse/parameters/enabled /sys/module/damon_sample_prcl/parameters/enabled /sys/module/damon_sample_mtier/parameters/enabled There is no functional changes in this patch. Link: https://lkml.kernel.org/r/20250707024548.1964-1-honggyu.kim@sk.com Signed-off-by: Honggyu Kim Reviewed-by: SeongJae Park Signed-off-by: Andrew Morton Stable-dep-of: c62cff40481c ("samples/damon/mtier: avoid starting DAMON before initialization") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

samples/damon/mtier: support boot time enable setup

2025-08-20T16:41:35Z

commit 964314344eab7bc43e38a32be281c5ea0609773b upstream. If 'enable' parameter of the 'mtier' DAMON sample module is set at boot time via the kernel command line, memory allocation is tried before the slab is initialized. As a result kernel NULL pointer dereference BUG can happen. Fix it by checking the initialization status. Link: https://lkml.kernel.org/r/20250706193207.39810-4-sj@kernel.org Fixes: 82a08bde3cf7 ("samples/damon: implement a DAMON module for memory tiering") Signed-off-by: SeongJae Park Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

samples/damon: fix damon sample mtier for start failure

2025-07-10T04:07:55Z

The damon_sample_mtier_start() can fail so we must reset the "enable" parameter to "false" again for proper rollback. In such cases, setting Y to "enable" then N triggers the similar crash with mtier because damon sample start failed but the "enable" stays as Y. Link: https://lkml.kernel.org/r/20250702000205.1921-4-honggyu.kim@sk.com Fixes: 82a08bde3cf7 ("samples/damon: implement a DAMON module for memory tiering") Signed-off-by: Honggyu Kim Reviewed-by: SeongJae Park Cc: Signed-off-by: Andrew Morton

samples/damon: implement a DAMON module for memory tiering

2025-05-13T06:50:30Z

Implement a sample DAMON module that shows how self-tuned DAMON-based memory tiering can be written. It is a sample since the purpose is to give an idea about how it can be implemented and perform, rather than be used on general production setups. Especially, it supports only two tiers memory setup having only one CPU-attached NUMA node. [sj@kernel.org: fix wrong DAMON attrs setting] Link: https://lkml.kernel.org/r/20250510220932.47722-1-sj@kernel.org [sj@kernel.org: trigger build even if only mtier is enabled] Link: https://lkml.kernel.org/r/20250426184054.11437-1-sj@kernel.org Link: https://lkml.kernel.org/r/20250420194030.75838-8-sj@kernel.org Signed-off-by: SeongJae Park Cc: Jonathan Corbet Cc: Yunjeong Mun Signed-off-by: Andrew Morton