[RFC PATCH 02/10] mm/damon/paddr: support addr_unit for access monitoring

[SeongJae Park <sj@kernel.org>]

Add support of addr_unit paramer for access monitoing operations of
paddr.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/damon/paddr.c | 32 +++++++++++++++++++++-----------
 1 file changed, 21 insertions(+), 11 deletions(-)

diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c
index b207c79ab9de..bc188aa2f01b 100644
--- a/mm/damon/paddr.c
+++ b/mm/damon/paddr.c
@@ -58,7 +58,13 @@ static void damon_folio_mkold(struct folio *folio)
 
 }
 
-static void damon_pa_mkold(unsigned long paddr)
+static phys_addr_t damon_pa_phys_addr(
+		unsigned long addr, unsigned long addr_unit)
+{
+	return (phys_addr_t)addr * addr_unit;
+}
+
+static void damon_pa_mkold(phys_addr_t paddr)
 {
 	struct folio *folio = damon_get_folio(PHYS_PFN(paddr));
 
@@ -69,11 +75,12 @@ static void damon_pa_mkold(unsigned long paddr)
 	folio_put(folio);
 }
 
-static void __damon_pa_prepare_access_check(struct damon_region *r)
+static void __damon_pa_prepare_access_check(struct damon_region *r,
+		unsigned long addr_unit)
 {
 	r->sampling_addr = damon_rand(r->ar.start, r->ar.end);
 
-	damon_pa_mkold(r->sampling_addr);
+	damon_pa_mkold(damon_pa_phys_addr(r->sampling_addr, addr_unit));
 }
 
 static void damon_pa_prepare_access_checks(struct damon_ctx *ctx)
@@ -83,7 +90,7 @@ static void damon_pa_prepare_access_checks(struct damon_ctx *ctx)
 
 	damon_for_each_target(t, ctx) {
 		damon_for_each_region(r, t)
-			__damon_pa_prepare_access_check(r);
+			__damon_pa_prepare_access_check(r, ctx->addr_unit);
 	}
 }
 
@@ -156,7 +163,7 @@ static bool damon_folio_young(struct folio *folio)
 	return accessed;
 }
 
-static bool damon_pa_young(unsigned long paddr, unsigned long *folio_sz)
+static bool damon_pa_young(phys_addr_t paddr, unsigned long *folio_sz)
 {
 	struct folio *folio = damon_get_folio(PHYS_PFN(paddr));
 	bool accessed;
@@ -171,23 +178,25 @@ static bool damon_pa_young(unsigned long paddr, unsigned long *folio_sz)
 }
 
 static void __damon_pa_check_access(struct damon_region *r,
-		struct damon_attrs *attrs)
+		struct damon_attrs *attrs, unsigned long addr_unit)
 {
-	static unsigned long last_addr;
+	static phys_addr_t last_addr;
 	static unsigned long last_folio_sz = PAGE_SIZE;
 	static bool last_accessed;
+	phys_addr_t sampling_addr = damon_pa_phys_addr(
+			r->sampling_addr, addr_unit);
 
 	/* If the region is in the last checked page, reuse the result */
 	if (ALIGN_DOWN(last_addr, last_folio_sz) ==
-				ALIGN_DOWN(r->sampling_addr, last_folio_sz)) {
+				ALIGN_DOWN(sampling_addr, last_folio_sz)) {
 		damon_update_region_access_rate(r, last_accessed, attrs);
 		return;
 	}
 
-	last_accessed = damon_pa_young(r->sampling_addr, &last_folio_sz);
+	last_accessed = damon_pa_young(sampling_addr, &last_folio_sz);
 	damon_update_region_access_rate(r, last_accessed, attrs);
 
-	last_addr = r->sampling_addr;
+	last_addr = sampling_addr;
 }
 
 static unsigned int damon_pa_check_accesses(struct damon_ctx *ctx)
@@ -198,7 +207,8 @@ static unsigned int damon_pa_check_accesses(struct damon_ctx *ctx)
 
 	damon_for_each_target(t, ctx) {
 		damon_for_each_region(r, t) {
-			__damon_pa_check_access(r, &ctx->attrs);
+			__damon_pa_check_access(
+					r, &ctx->attrs, ctx->addr_unit);
 			max_nr_accesses = max(r->nr_accesses, max_nr_accesses);
 		}
 	}
-- 
2.39.5