kernel/mm/damon/tests/vaddr-kunit.h, branch linux-rolling-stable

mm/damon: rename DAMON_MIN_REGION to DAMON_MIN_REGION_SZ

2026-03-19T15:15:32Z

[ Upstream commit dfb1b0c9dc0d61e422905640e1e7334b3cf6f384 ] The macro is for the default minimum size of each DAMON region. There was a case that a reader was confused if it is the minimum number of total DAMON regions, which is set on damon_attrs->min_nr_regions. Make the name more explicit. Link: https://lkml.kernel.org/r/20260117175256.82826-8-sj@kernel.org Signed-off-by: SeongJae Park Signed-off-by: Andrew Morton Stable-dep-of: c80f46ac228b ("mm/damon/core: disallow non-power of two min_region_sz") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

mm/damon/tests/vaddr-kunit: handle alloc failures on damon_test_split_evenly_succ()

2025-11-17T01:28:34Z

damon_test_split_evenly_succ() is assuming all dynamic memory allocation in it will succeed. Those are indeed likely in the real use cases since those allocations are too small to fail, but theoretically those could fail. In the case, inappropriate memory access can happen. Fix it by appropriately cleanup pre-allocated memory and skip the execution of the remaining tests in the failure cases. Link: https://lkml.kernel.org/r/20251101182021.74868-20-sj@kernel.org Fixes: 17ccae8bb5c9 ("mm/damon: add kunit tests") Signed-off-by: SeongJae Park Cc: Brendan Higgins Cc: David Gow Cc: Kefeng Wang Cc: [5.15+] Signed-off-by: Andrew Morton

mm/damon/tests/vaddr-kunit: handle alloc failures in damon_test_split_evenly_fail()

2025-11-17T01:28:34Z

damon_test_split_evenly_fail() is assuming all dynamic memory allocation in it will succeed. Those are indeed likely in the real use cases since those allocations are too small to fail, but theoretically those could fail. In the case, inappropriate memory access can happen. Fix it by appropriately cleanup pre-allocated memory and skip the execution of the remaining tests in the failure cases. Link: https://lkml.kernel.org/r/20251101182021.74868-19-sj@kernel.org Fixes: 17ccae8bb5c9 ("mm/damon: add kunit tests") Signed-off-by: SeongJae Park Cc: Brendan Higgins Cc: David Gow Cc: Kefeng Wang Cc: [5.15+] Signed-off-by: Andrew Morton

mm/damon/tests/vaddr-kunit: handle alloc failures on damon_do_test_apply_three_regions()

2025-11-17T01:28:34Z

damon_do_test_apply_three_regions() is assuming all dynamic memory allocation in it will succeed. Those are indeed likely in the real use cases since those allocations are too small to fail, but theoretically those could fail. In the case, inappropriate memory access can happen. Fix it by appropriately cleanup pre-allocated memory and skip the execution of the remaining tests in the failure cases. Link: https://lkml.kernel.org/r/20251101182021.74868-18-sj@kernel.org Fixes: 17ccae8bb5c9 ("mm/damon: add kunit tests") Signed-off-by: SeongJae Park Cc: Brendan Higgins Cc: David Gow Cc: Kefeng Wang Cc: [5.15+] Signed-off-by: Andrew Morton

mm/damon: add damon_ctx->min_sz_region

2025-09-13T23:55:24Z

Adopting addr_unit would make DAMON_MINREGION 'addr_unit * 4096' bytes and cause data alignment issues[1]. Add damon_ctx->min_sz_region to change DAMON_MIN_REGION from a global macro value to per-context variable. Link: https://lkml.kernel.org/r/20250828171242.59810-12-sj@kernel.org Link: https://lore.kernel.org/all/527714dd-0e33-43ab-bbbd-d89670ba79e7@huawei.com [1] Signed-off-by: Quanmin Yan Signed-off-by: SeongJae Park Reviewed-by: SeongJae Park Cc: David Hildenbrand Cc: Jonathan Corbet Cc: Kefeng Wang Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Mike Rapoport Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: ze zuo Signed-off-by: Andrew Morton

mm/damon/core: add cleanup_target() ops callback

2025-07-20T01:59:56Z

Some DAMON operation sets may need additional cleanup per target. For example, [f]vaddr need to put pids of each target. Each user and core logic is doing that redundantly. Add another DAMON ops callback that will be used for doing such cleanups in operations set layer. [sj@kernel.org: add kernel-doc comment for damon_operations->cleanup_target] Link: https://lkml.kernel.org/r/20250715185239.89152-2-sj@kernel.org [sj@kernel.org: remove damon_ctx->callback kernel-doc comment] Link: https://lkml.kernel.org/r/20250715185239.89152-3-sj@kernel.org Link: https://lkml.kernel.org/r/20250712195016.151108-10-sj@kernel.org Signed-off-by: SeongJae Park Signed-off-by: Andrew Morton

mm/damon/tests/vaddr-kunit.h: reduce stack consumption

2025-01-14T06:40:50Z

After "mm: move per-vma lock into vm_area_struct" we're hitting mm/damon/tests/vaddr-kunit.h: In function 'damon_test_three_regions_in_vmas': mm/damon/tests/vaddr-kunit.h:92:1: error: the frame size of 3280 bytes is larger than 2048 bytes [-Werror=frame-larger-than=] Fix by moving all those vmas off the stack. [akpm@linux-foundation.org: fix build] Closes: https://lkml.kernel.org/r/20241209170829.11311e70@canb.auug.org.au Reported-by: Stephen Rothwell Reviewed-by: SeongJae Park Cc: Suren Baghdasaryan Signed-off-by: Andrew Morton

mm/damon/vaddr: add 'nr_piece == 1' check in damon_va_evenly_split_region()

2024-11-07T04:11:18Z

As discussed in [1], damon_va_evenly_split_region() is called to size-evenly split a region into 'nr_pieces' small regions, when nr_pieces == 1, no actual split is required. Check that case for better code readability and add a simple kunit testcase. [1] https://lore.kernel.org/all/20241021163316.12443-1-sj@kernel.org/ Link: https://lkml.kernel.org/r/20241022083927.3592237-3-zhengyejian@huaweicloud.com Signed-off-by: Zheng Yejian Reviewed-by: SeongJae Park Cc: Fernand Sieber Cc: Leonard Foerster Cc: Shakeel Butt Cc: Ye Weihua Signed-off-by: Andrew Morton

mm/damon/vaddr: fix issue in damon_va_evenly_split_region()

2024-11-07T04:11:18Z

Patch series "mm/damon/vaddr: Fix issue in damon_va_evenly_split_region()". v2. According to the logic of damon_va_evenly_split_region(), currently following split case would not meet the expectation: Suppose DAMON_MIN_REGION=0x1000, Case: Split [0x0, 0x3000) into 2 pieces, then the result would be acutually 3 regions: [0x0, 0x1000), [0x1000, 0x2000), [0x2000, 0x3000) but NOT the expected 2 regions: [0x0, 0x1000), [0x1000, 0x3000) !!! The root cause is that when calculating size of each split piece in damon_va_evenly_split_region(): `sz_piece = ALIGN_DOWN(sz_orig / nr_pieces, DAMON_MIN_REGION);` both the dividing and the ALIGN_DOWN may cause loss of precision, then each time split one piece of size 'sz_piece' from origin 'start' to 'end' would cause more pieces are split out than expected!!! To fix it, count for each piece split and make sure no more than 'nr_pieces'. In addition, add above case into damon_test_split_evenly(). And add 'nr_piece == 1' check in damon_va_evenly_split_region() for better code readability and add a corresponding kunit testcase. This patch (of 2): According to the logic of damon_va_evenly_split_region(), currently following split case would not meet the expectation: Suppose DAMON_MIN_REGION=0x1000, Case: Split [0x0, 0x3000) into 2 pieces, then the result would be acutually 3 regions: [0x0, 0x1000), [0x1000, 0x2000), [0x2000, 0x3000) but NOT the expected 2 regions: [0x0, 0x1000), [0x1000, 0x3000) !!! The root cause is that when calculating size of each split piece in damon_va_evenly_split_region(): `sz_piece = ALIGN_DOWN(sz_orig / nr_pieces, DAMON_MIN_REGION);` both the dividing and the ALIGN_DOWN may cause loss of precision, then each time split one piece of size 'sz_piece' from origin 'start' to 'end' would cause more pieces are split out than expected!!! To fix it, count for each piece split and make sure no more than 'nr_pieces'. In addition, add above case into damon_test_split_evenly(). After this patch, damon-operations test passed: # ./tools/testing/kunit/kunit.py run damon-operations [...] ============== damon-operations (6 subtests) =============== [PASSED] damon_test_three_regions_in_vmas [PASSED] damon_test_apply_three_regions1 [PASSED] damon_test_apply_three_regions2 [PASSED] damon_test_apply_three_regions3 [PASSED] damon_test_apply_three_regions4 [PASSED] damon_test_split_evenly ================ [PASSED] damon-operations ================= Link: https://lkml.kernel.org/r/20241022083927.3592237-1-zhengyejian@huaweicloud.com Link: https://lkml.kernel.org/r/20241022083927.3592237-2-zhengyejian@huaweicloud.com Fixes: 3f49584b262c ("mm/damon: implement primitives for the virtual memory address spaces") Signed-off-by: Zheng Yejian Reviewed-by: SeongJae Park Cc: Fernand Sieber Cc: Leonard Foerster Cc: Shakeel Butt Cc: Ye Weihua Cc: Signed-off-by: Andrew Morton

mm/damon: fix sparse warning for zero initializer

2024-11-06T00:56:21Z

sparse warns about zero initializing an array with {0,}, change it to the equivalent {0}. Fixes the sparse warning: mm/damon/tests/vaddr-kunit.h:69:47: warning: missing braces around initializer Link: https://lkml.kernel.org/r/xriwklcwjpwcz7eiavo6f7envdar4jychhsk6sfkj5klaznb6b@j6vrvr2sxjht Fixes: 17ccae8bb5c9 ("mm/damon: add kunit tests") Signed-off-by: Leo Stone Reviewed-by: SeongJae Park Cc: Jinjie Ruan Cc: Shuah Khan Signed-off-by: Andrew Morton