From: Quanmin Yan Date: Mon, 20 Oct 2025 13:01:25 +0000 (+0800) Subject: mm/damon/reclaim: use min_sz_region for core address alignment when setting regions X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=dfc02531f413bf18f5e0ac79a52d2af6f69e99c3;p=thirdparty%2Fkernel%2Flinux.git mm/damon/reclaim: use min_sz_region for core address alignment when setting regions When setting regions in DAMON_RECLAIM, DAMON_MIN_REGION will be applied 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_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, use min_sz_region for core address alignment when setting regions. Link: https://lkml.kernel.org/r/20251020130125.2875164-3-yanquanmin1@huawei.com Fixes: 7db551fcfb2a ("mm/damon/reclaim: support addr_unit for DAMON_RECLAIM") Signed-off-by: Quanmin Yan Reviewed-by: SeongJae Park Cc: Kefeng Wang Cc: ze zuo Signed-off-by: Andrew Morton --- diff --git a/mm/damon/reclaim.c b/mm/damon/reclaim.c index e30811cafe90c..36a582e09eaef 100644 --- a/mm/damon/reclaim.c +++ b/mm/damon/reclaim.c @@ -251,7 +251,7 @@ static int damon_reclaim_apply_parameters(void) err = damon_set_region_biggest_system_ram_default(param_target, &monitor_region_start, &monitor_region_end, - DAMON_MIN_REGION); + param_ctx->min_sz_region); if (err) goto out; err = damon_commit_ctx(ctx, param_ctx);