kernel/git/stable/linux-stable.git/samples/damon, branch master

samples/damon/mtier: fail early if address range parameters are invalid

2026-07-02T02:02:56+00:00

The comment on top of `struct damon_region` clearly says that For any use case, @ar should be non-zero positive size. which is now verified in damon_verify_new_region() if the kernel is built with DAMON_DEBUG_SANITY. The WARN_ONCE() can be triggered if the mtier sample module is enabled before node{0,1}_{start,end}_addr have been properly initialized, which is obviously not good. ------------[ cut here ]------------ start 0 >= end 0 WARNING: mm/damon/core.c:217 at damon_new_region+0xf4/0x118, CPU#59: bash/341468 Call trace: damon_new_region+0xf4/0x118 (P) damon_set_regions+0xfc/0x3c0 damon_sample_mtier_build_ctx+0xe8/0x3a8 damon_sample_mtier_start+0x1c/0x90 damon_sample_mtier_enable_store+0x98/0xb0 param_attr_store+0xb4/0x128 module_attr_store+0x2c/0x50 sysfs_kf_write+0x58/0x90 kernfs_fop_write_iter+0x16c/0x238 vfs_write+0x2c0/0x370 ksys_write+0x74/0x118 __arm64_sys_write+0x24/0x38 invoke_syscall+0xa8/0x118 el0_svc_common.constprop.0+0x48/0xf0 do_el0_svc+0x24/0x38 el0_svc+0x54/0x370 el0t_64_sync_handler+0xa0/0xe8 el0t_64_sync+0x1ac/0x1b0 ---[ end trace 0000000000000000 ]--- Note that the same issue can happen if detect_node_addresses is true, and node 0 or 1 is memoryless. Fix it together by checking the validity of parameters right before damon_new_region() and fail early if they're invalid. Link: https://lore.kernel.org/20260629144432.133962-1-sj@kernel.org Fixes: 82a08bde3cf7 ("samples/damon: implement a DAMON module for memory tiering") Signed-off-by: Zenghui Yu Signed-off-by: SJ Park Reviewed-by: SJ Park Cc: # 6.16.x Signed-off-by: Andrew Morton

samples/damon/mtier: replace damon_add_region() with damon_set_regions()

2026-06-04T21:45:00+00:00

mtier DAMON sample module and DAMON virtual address operation set (vaddr) unit tests are using damon_add_region() for setup of DAMON monitoring target region boundaries setup. But, damon_set_regions() is designed for exactly the purpose. All other DAMON API callers use the function for the purpose. Replace damon_add_region() usage in mtier sample module with damon_set_regions(), for unifying the use case and reducing the maintenance cost. Link: https://lore.kernel.org/20260522154026.80546-4-sj@kernel.org Signed-off-by: SeongJae Park Cc: Brendan Higgins Cc: Shuah Khan Signed-off-by: Andrew Morton

samples/damon/mtier: use damon_initialized()

2025-09-21T21:22:39+00:00

damon_sample_mtier is assuming DAMON is ready to use in module_init time, and uses its own hack to see if it is the time. Use damon_initialized(), which is a way for seeing if DAMON is ready to be used that is more reliable and better to maintain instead of the hack. Link: https://lkml.kernel.org/r/20250916033511.116366-8-sj@kernel.org Signed-off-by: SeongJae Park Signed-off-by: Andrew Morton

samples/damon/prcl: use damon_initialized()

2025-09-21T21:22:38+00:00

damon_sample_prcl is assuming DAMON is ready to use in module_init time, and uses its own hack to see if it is the time. Use damon_initialized(), which is a way for seeing if DAMON is ready to be used that is more reliable and better to maintain instead of the hack. Link: https://lkml.kernel.org/r/20250916033511.116366-7-sj@kernel.org Signed-off-by: SeongJae Park Signed-off-by: Andrew Morton

samples/damon/wsse: use damon_initialized()

2025-09-21T21:22:38+00:00

damon_sample_wsse is assuming DAMON is ready to use in module_init time, and uses its own hack to see if it is the time. Use damon_initialized(), which is a way for seeing if DAMON is ready to be used that is more reliable and better to maintain instead of the hack. Link: https://lkml.kernel.org/r/20250916033511.116366-6-sj@kernel.org Signed-off-by: SeongJae Park Signed-off-by: Andrew Morton

samples/damon/mtier: avoid starting DAMON before initialization

2025-09-13T20:05:38+00:00

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

samples/damon/prcl: avoid starting DAMON before initialization

2025-09-13T20:05:37+00:00

Commit 2780505ec2b4 ("samples/damon/prcl: fix boot time enable crash") 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/20250909022238.2989-3-sj@kernel.org Link: https://lore.kernel.org/20250706193207.39810-3-sj@kernel.org [1] Fixes: 2780505ec2b4 ("samples/damon/prcl: fix boot time enable crash") Signed-off-by: SeongJae Park Cc: Signed-off-by: Andrew Morton

samples/damon/wsse: avoid starting DAMON before initialization

2025-09-13T20:05:37+00:00

Patch series "samples/damon: fix boot time enable handling fixup merge mistakes". First three patches of the patch series "mm/damon: fix misc bugs in DAMON modules" [1] were trying to fix boot time DAMON sample modules enabling issues. The issues are the modules can crash if those are enabled before DAMON is enabled, like using boot time parameter options. The three patches were fixing the issues by avoiding starting DAMON before the module initialization phase. However, probably by a mistake during a merge, only half of the change is merged, and the part for avoiding the starting of DAMON before the module initialized is missed. So the problem is not solved and thus the modules can still crash if enabled before DAMON is initialized. Fix those by applying the unmerged parts again. Note that the broken commits are merged into 6.17-rc1, but also backported to relevant stable kernels. So this series also needs to be merged into the stable kernels. Hence Cc-ing stable@. This patch (of 3): Commit 0ed1165c3727 ("samples/damon/wsse: fix boot time enable handling") is somehow incompletely applying the origin patch [2]. 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/20250909022238.2989-1-sj@kernel.org Link: https://lkml.kernel.org/r/20250909022238.2989-2-sj@kernel.org Link: https://lkml.kernel.org/r/20250706193207.39810-1-sj@kernel.org [1] Link: https://lore.kernel.org/20250706193207.39810-2-sj@kernel.org [2] Fixes: 0ed1165c3727 ("samples/damon/wsse: fix boot time enable handling") Signed-off-by: SeongJae Park Cc: Signed-off-by: Andrew Morton

mm/damon/vaddr: put pid in cleanup_target()

2025-07-20T01:59:56+00:00

Implement cleanup_target() callback for [f]vaddr, which calls put_pid() for each target that will be destroyed. Also remove redundant put_pid() calls in core, sysfs and sample modules, which were required to be done redundantly due to the lack of such self cleanup in vaddr. Link: https://lkml.kernel.org/r/20250712195016.151108-11-sj@kernel.org Signed-off-by: SeongJae Park Signed-off-by: Andrew Morton

samples/damon/wsse: use damon_call() repeat mode instead of damon_callback

2025-07-20T01:59:55+00:00

wsse uses damon_callback for periodically reading DAMON internal data. Use its alternative, damon_call() repeat mode. Link: https://lkml.kernel.org/r/20250712195016.151108-8-sj@kernel.org Signed-off-by: SeongJae Park Signed-off-by: Andrew Morton