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mm/damon: add a min_sz_region parameter to damon_set_region_biggest_system_ram_default()
Patch series "mm/damon: fixes for address alignment issues in DAMON_LRU_SORT and DAMON_RECLAIM", v2. In DAMON_LRU_SORT and DAMON_RECLAIM, damon_set_regions() will apply DAMON_MIN_REGION as the core address alignment, and the monitoring target address ranges would be aligned on DAMON_MIN_REGION * addr_unit. When users 1) set addr_unit to a value larger than 1, and 2) set the monitoring target address range as not aligned on DAMON_MIN_REGION * addr_unit, it will cause DAMON_LRU_SORT and DAMON_RECLAIM to operate on unexpectedly large physical address ranges. For example, if the user sets the monitoring target address range to [4, 8) and addr_unit as 1024, the aimed monitoring target address range is [4 KiB, 8 KiB). Assuming DAMON_MIN_REGION is 4096, so resulting target address range will be [0, 4096) in the DAMON core layer address system, and [0, 4 MiB) in the physical address space, which is an unexpected range. To fix the issue, add a min_sz_region parameter to damon_set_region_biggest_system_ram_default() and use it when calling damon_set_regions(), replacing the direct use of DAMON_MIN_REGION. This patch (of 2): In DAMON_LRU_SORT, damon_set_regions() will apply DAMON_MIN_REGION as the core address alignment, and the monitoring target address ranges would be aligned on DAMON_MIN_REGION * addr_unit. When users 1) set addr_unit to a value larger than 1, and 2) set the monitoring target address range as not aligned on DAMON_MIN_REGION * addr_unit, it will cause DAMON_LRU_SORT to operate on unexpectedly large physical address ranges. For example, if the user sets the monitoring target address range to [4, 8) and addr_unit as 1024, the aimed monitoring target address range is [4 KiB, 8 KiB). Assuming DAMON_MIN_REGION is 4096, so resulting target address range will be [0, 4096) in the DAMON core layer address system, and [0, 4 MiB) in the physical address space, which is an unexpected range. To fix the issue, add a min_sz_region parameter to damon_set_region_biggest_system_ram_default() and use it when calling damon_set_regions(), replacing the direct use of DAMON_MIN_REGION. Link: https://lkml.kernel.org/r/20251020130125.2875164-1-yanquanmin1@huawei.com Link: https://lkml.kernel.org/r/20251020130125.2875164-2-yanquanmin1@huawei.com Fixes: 2e0fe924 ("mm/damon/lru_sort: support addr_unit for DAMON_LRU_SORT") Signed-off-by:Quanmin Yan <yanquanmin1@huawei.com> Reviewed-by:
SeongJae Park <sj@kernel.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: ze zuo <zuoze1@huawei.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org>