From: Quanmin Yan Date: Mon, 20 Oct 2025 13:01:24 +0000 (+0800) Subject: mm/damon: add a min_sz_region parameter to damon_set_region_biggest_system_ram_default() X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=368b3cbaf2b8d1932c573e68e73178387439157b;p=users%2Fjedix%2Flinux-maple.git 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: 2e0fe9245d6b ("mm/damon/lru_sort: support addr_unit for DAMON_LRU_SORT") Signed-off-by: Quanmin Yan Reviewed-by: SeongJae Park Cc: Kefeng Wang Cc: ze zuo Signed-off-by: Andrew Morton --- diff --git a/include/linux/damon.h b/include/linux/damon.h index 0edf41d36ea1..9ee026c2db53 100644 --- a/include/linux/damon.h +++ b/include/linux/damon.h @@ -961,7 +961,8 @@ int damon_call(struct damon_ctx *ctx, struct damon_call_control *control); int damos_walk(struct damon_ctx *ctx, struct damos_walk_control *control); int damon_set_region_biggest_system_ram_default(struct damon_target *t, - unsigned long *start, unsigned long *end); + unsigned long *start, unsigned long *end, + unsigned long min_sz_region); #endif /* CONFIG_DAMON */ diff --git a/mm/damon/core.c b/mm/damon/core.c index a9c11d2d37b0..82546d138a5a 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -2818,6 +2818,7 @@ static bool damon_find_biggest_system_ram(unsigned long *start, * @t: The monitoring target to set the region. * @start: The pointer to the start address of the region. * @end: The pointer to the end address of the region. + * @min_sz_region: Minimum region size. * * This function sets the region of @t as requested by @start and @end. If the * values of @start and @end are zero, however, this function finds the biggest @@ -2828,7 +2829,8 @@ static bool damon_find_biggest_system_ram(unsigned long *start, * Return: 0 on success, negative error code otherwise. */ int damon_set_region_biggest_system_ram_default(struct damon_target *t, - unsigned long *start, unsigned long *end) + unsigned long *start, unsigned long *end, + unsigned long min_sz_region) { struct damon_addr_range addr_range; @@ -2841,7 +2843,7 @@ int damon_set_region_biggest_system_ram_default(struct damon_target *t, addr_range.start = *start; addr_range.end = *end; - return damon_set_regions(t, &addr_range, 1, DAMON_MIN_REGION); + return damon_set_regions(t, &addr_range, 1, min_sz_region); } /* diff --git a/mm/damon/lru_sort.c b/mm/damon/lru_sort.c index 42b9a656f9de..49b4bc294f4e 100644 --- a/mm/damon/lru_sort.c +++ b/mm/damon/lru_sort.c @@ -242,7 +242,8 @@ static int damon_lru_sort_apply_parameters(void) err = damon_set_region_biggest_system_ram_default(param_target, &monitor_region_start, - &monitor_region_end); + &monitor_region_end, + param_ctx->min_sz_region); if (err) goto out; err = damon_commit_ctx(ctx, param_ctx); diff --git a/mm/damon/reclaim.c b/mm/damon/reclaim.c index 7ba3d0f9a19a..e30811cafe90 100644 --- a/mm/damon/reclaim.c +++ b/mm/damon/reclaim.c @@ -250,7 +250,8 @@ static int damon_reclaim_apply_parameters(void) err = damon_set_region_biggest_system_ram_default(param_target, &monitor_region_start, - &monitor_region_end); + &monitor_region_end, + DAMON_MIN_REGION); if (err) goto out; err = damon_commit_ctx(ctx, param_ctx); diff --git a/mm/damon/stat.c b/mm/damon/stat.c index d8010968bbed..6c4503d2aee3 100644 --- a/mm/damon/stat.c +++ b/mm/damon/stat.c @@ -187,7 +187,8 @@ static struct damon_ctx *damon_stat_build_ctx(void) if (!target) goto free_out; damon_add_target(ctx, target); - if (damon_set_region_biggest_system_ram_default(target, &start, &end)) + if (damon_set_region_biggest_system_ram_default(target, &start, &end, + ctx->min_sz_region)) goto free_out; return ctx; free_out: