mm/damon: add damon_ctx->min_sz_region

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
Signed-off-by: Quanmin Yan <yanquanmin1@huawei.com>
Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: ze zuo <zuoze1@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/damon.h b/include/linux/damon.h
index 43d997aad2545542b9540f7b16a158edfc7ad10d..aa7381be388cadfec815845b71a28060d320bf5e 100644 (file)
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -749,6 +749,7 @@ struct damon_attrs {
  *
  * @ops:       Set of monitoring operations for given use cases.
  * @addr_unit: Scale factor for core to ops address conversion.
+ * @min_sz_region:             Minimum region size.
  * @adaptive_targets:  Head of monitoring targets (&damon_target) list.
  * @schemes:           Head of schemes (&damos) list.
  */
@@ -791,6 +792,7 @@ struct damon_ctx {
 
        struct damon_operations ops;
        unsigned long addr_unit;
+       unsigned long min_sz_region;
 
        struct list_head adaptive_targets;
        struct list_head schemes;
@@ -879,7 +881,7 @@ static inline void damon_insert_region(struct damon_region *r,
 void damon_add_region(struct damon_region *r, struct damon_target *t);
 void damon_destroy_region(struct damon_region *r, struct damon_target *t);
 int damon_set_regions(struct damon_target *t, struct damon_addr_range *ranges,
-               unsigned int nr_ranges);
+               unsigned int nr_ranges, unsigned long min_sz_region);
 void damon_update_region_access_rate(struct damon_region *r, bool accessed,
                struct damon_attrs *attrs);
 

diff --git a/mm/damon/core.c b/mm/damon/core.c
index 9776891cbfa40afaff3ae3a2b41df0737b374f08..be5942435d7823c415dac0a38076f3404bccd336 100644 (file)
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -201,6 +201,7 @@ static int damon_fill_regions_holes(struct damon_region *first,
  * @t:         the given target.
  * @ranges:    array of new monitoring target ranges.
  * @nr_ranges: length of @ranges.
+ * @min_sz_region:     minimum region size.
  *
  * This function adds new regions to, or modify existing regions of a
  * monitoring target to fit in specific ranges.
@@ -208,7 +209,7 @@ static int damon_fill_regions_holes(struct damon_region *first,
  * Return: 0 if success, or negative error code otherwise.
  */
 int damon_set_regions(struct damon_target *t, struct damon_addr_range *ranges,
-               unsigned int nr_ranges)
+               unsigned int nr_ranges, unsigned long min_sz_region)
 {
        struct damon_region *r, *next;
        unsigned int i;
@@ -245,16 +246,16 @@ int damon_set_regions(struct damon_target *t, struct damon_addr_range *ranges,
                        /* no region intersects with this range */
                        newr = damon_new_region(
                                        ALIGN_DOWN(range->start,
-                                               DAMON_MIN_REGION),
-                                       ALIGN(range->end, DAMON_MIN_REGION));
+                                               min_sz_region),
+                                       ALIGN(range->end, min_sz_region));
                        if (!newr)
                                return -ENOMEM;
                        damon_insert_region(newr, damon_prev_region(r), r, t);
                } else {
                        /* resize intersecting regions to fit in this range */
                        first->ar.start = ALIGN_DOWN(range->start,
-                                       DAMON_MIN_REGION);
-                       last->ar.end = ALIGN(range->end, DAMON_MIN_REGION);
+                                       min_sz_region);
+                       last->ar.end = ALIGN(range->end, min_sz_region);
 
                        /* fill possible holes in the range */
                        err = damon_fill_regions_holes(first, last, t);
@@ -545,6 +546,7 @@ struct damon_ctx *damon_new_ctx(void)
        ctx->attrs.max_nr_regions = 1000;
 
        ctx->addr_unit = 1;
+       ctx->min_sz_region = DAMON_MIN_REGION;
 
        INIT_LIST_HEAD(&ctx->adaptive_targets);
        INIT_LIST_HEAD(&ctx->schemes);
@@ -1127,8 +1129,8 @@ static struct damon_target *damon_nth_target(int n, struct damon_ctx *ctx)
  *
  * If @src has no region, @dst keeps current regions.
  */
-static int damon_commit_target_regions(
-               struct damon_target *dst, struct damon_target *src)
+static int damon_commit_target_regions(struct damon_target *dst,
+               struct damon_target *src, unsigned long src_min_sz_region)
 {
        struct damon_region *src_region;
        struct damon_addr_range *ranges;
@@ -1145,18 +1147,19 @@ static int damon_commit_target_regions(
        i = 0;
        damon_for_each_region(src_region, src)
                ranges[i++] = src_region->ar;
-       err = damon_set_regions(dst, ranges, i);
+       err = damon_set_regions(dst, ranges, i, src_min_sz_region);
        kfree(ranges);
        return err;
 }
 
 static int damon_commit_target(
                struct damon_target *dst, bool dst_has_pid,
-               struct damon_target *src, bool src_has_pid)
+               struct damon_target *src, bool src_has_pid,
+               unsigned long src_min_sz_region)
 {
        int err;
 
-       err = damon_commit_target_regions(dst, src);
+       err = damon_commit_target_regions(dst, src, src_min_sz_region);
        if (err)
                return err;
        if (dst_has_pid)
@@ -1178,7 +1181,8 @@ static int damon_commit_targets(
                if (src_target) {
                        err = damon_commit_target(
                                        dst_target, damon_target_has_pid(dst),
-                                       src_target, damon_target_has_pid(src));
+                                       src_target, damon_target_has_pid(src),
+                                       src->min_sz_region);
                        if (err)
                                return err;
                } else {
@@ -1201,7 +1205,8 @@ static int damon_commit_targets(
                if (!new_target)
                        return -ENOMEM;
                err = damon_commit_target(new_target, false,
-                               src_target, damon_target_has_pid(src));
+                               src_target, damon_target_has_pid(src),
+                               src->min_sz_region);
                if (err) {
                        damon_destroy_target(new_target, NULL);
                        return err;
@@ -1248,6 +1253,7 @@ int damon_commit_ctx(struct damon_ctx *dst, struct damon_ctx *src)
        }
        dst->ops = src->ops;
        dst->addr_unit = src->addr_unit;
+       dst->min_sz_region = src->min_sz_region;
 
        return 0;
 }
@@ -1280,8 +1286,8 @@ static unsigned long damon_region_sz_limit(struct damon_ctx *ctx)
 
        if (ctx->attrs.min_nr_regions)
                sz /= ctx->attrs.min_nr_regions;
-       if (sz < DAMON_MIN_REGION)
-               sz = DAMON_MIN_REGION;
+       if (sz < ctx->min_sz_region)
+               sz = ctx->min_sz_region;
 
        return sz;
 }
@@ -1625,6 +1631,7 @@ static bool damos_valid_target(struct damon_ctx *c, struct damon_target *t,
  * @t: The target of the region.
  * @rp:        The pointer to the region.
  * @s: The scheme to be applied.
+ * @min_sz_region:     minimum region size.
  *
  * If a quota of a scheme has exceeded in a quota charge window, the scheme's
  * action would applied to only a part of the target access pattern fulfilling
@@ -1642,7 +1649,7 @@ static bool damos_valid_target(struct damon_ctx *c, struct damon_target *t,
  * Return: true if the region should be entirely skipped, false otherwise.
  */
 static bool damos_skip_charged_region(struct damon_target *t,
-               struct damon_region **rp, struct damos *s)
+               struct damon_region **rp, struct damos *s, unsigned long min_sz_region)
 {
        struct damon_region *r = *rp;
        struct damos_quota *quota = &s->quota;
@@ -1664,11 +1671,11 @@ static bool damos_skip_charged_region(struct damon_target *t,
                if (quota->charge_addr_from && r->ar.start <
                                quota->charge_addr_from) {
                        sz_to_skip = ALIGN_DOWN(quota->charge_addr_from -
-                                       r->ar.start, DAMON_MIN_REGION);
+                                       r->ar.start, min_sz_region);
                        if (!sz_to_skip) {
-                               if (damon_sz_region(r) <= DAMON_MIN_REGION)
+                               if (damon_sz_region(r) <= min_sz_region)
                                        return true;
-                               sz_to_skip = DAMON_MIN_REGION;
+                               sz_to_skip = min_sz_region;
                        }
                        damon_split_region_at(t, r, sz_to_skip);
                        r = damon_next_region(r);
@@ -1693,7 +1700,8 @@ static void damos_update_stat(struct damos *s,
 }
 
 static bool damos_filter_match(struct damon_ctx *ctx, struct damon_target *t,
-               struct damon_region *r, struct damos_filter *filter)
+               struct damon_region *r, struct damos_filter *filter,
+               unsigned long min_sz_region)
 {
        bool matched = false;
        struct damon_target *ti;
@@ -1710,8 +1718,8 @@ static bool damos_filter_match(struct damon_ctx *ctx, struct damon_target *t,
                matched = target_idx == filter->target_idx;
                break;
        case DAMOS_FILTER_TYPE_ADDR:
-               start = ALIGN_DOWN(filter->addr_range.start, DAMON_MIN_REGION);
-               end = ALIGN_DOWN(filter->addr_range.end, DAMON_MIN_REGION);
+               start = ALIGN_DOWN(filter->addr_range.start, min_sz_region);
+               end = ALIGN_DOWN(filter->addr_range.end, min_sz_region);
 
                /* inside the range */
                if (start <= r->ar.start && r->ar.end <= end) {
@@ -1747,7 +1755,7 @@ static bool damos_filter_out(struct damon_ctx *ctx, struct damon_target *t,
 
        s->core_filters_allowed = false;
        damos_for_each_filter(filter, s) {
-               if (damos_filter_match(ctx, t, r, filter)) {
+               if (damos_filter_match(ctx, t, r, filter, ctx->min_sz_region)) {
                        if (filter->allow)
                                s->core_filters_allowed = true;
                        return !filter->allow;
@@ -1882,7 +1890,7 @@ static void damos_apply_scheme(struct damon_ctx *c, struct damon_target *t,
        if (c->ops.apply_scheme) {
                if (quota->esz && quota->charged_sz + sz > quota->esz) {
                        sz = ALIGN_DOWN(quota->esz - quota->charged_sz,
-                                       DAMON_MIN_REGION);
+                                       c->min_sz_region);
                        if (!sz)
                                goto update_stat;
                        damon_split_region_at(t, r, sz);
@@ -1930,7 +1938,7 @@ static void damon_do_apply_schemes(struct damon_ctx *c,
                if (quota->esz && quota->charged_sz >= quota->esz)
                        continue;
 
-               if (damos_skip_charged_region(t, &r, s))
+               if (damos_skip_charged_region(t, &r, s, c->min_sz_region))
                        continue;
 
                if (!damos_valid_target(c, t, r, s))
@@ -2328,7 +2336,8 @@ static void damon_split_region_at(struct damon_target *t,
 }
 
 /* Split every region in the given target into 'nr_subs' regions */
-static void damon_split_regions_of(struct damon_target *t, int nr_subs)
+static void damon_split_regions_of(struct damon_target *t, int nr_subs,
+                                 unsigned long min_sz_region)
 {
        struct damon_region *r, *next;
        unsigned long sz_region, sz_sub = 0;
@@ -2338,13 +2347,13 @@ static void damon_split_regions_of(struct damon_target *t, int nr_subs)
                sz_region = damon_sz_region(r);
 
                for (i = 0; i < nr_subs - 1 &&
-                               sz_region > 2 * DAMON_MIN_REGION; i++) {
+                               sz_region > 2 * min_sz_region; i++) {
                        /*
                         * Randomly select size of left sub-region to be at
                         * least 10 percent and at most 90% of original region
                         */
                        sz_sub = ALIGN_DOWN(damon_rand(1, 10) *
-                                       sz_region / 10, DAMON_MIN_REGION);
+                                       sz_region / 10, min_sz_region);
                        /* Do not allow blank region */
                        if (sz_sub == 0 || sz_sub >= sz_region)
                                continue;
@@ -2384,7 +2393,7 @@ static void kdamond_split_regions(struct damon_ctx *ctx)
                nr_subregions = 3;
 
        damon_for_each_target(t, ctx)
-               damon_split_regions_of(t, nr_subregions);
+               damon_split_regions_of(t, nr_subregions, ctx->min_sz_region);
 
        last_nr_regions = nr_regions;
 }
@@ -2777,7 +2786,7 @@ 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);
+       return damon_set_regions(t, &addr_range, 1, DAMON_MIN_REGION);
 }
 
 /*

diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c
index e0023f2c9bacbaf2dd919c85150a76ce0d1ceaec..fe4e73d0ebbb4d4f0245789c3cf8f76aa0eca6e5 100644 (file)
--- a/mm/damon/sysfs.c
+++ b/mm/damon/sysfs.c
@@ -1333,7 +1333,8 @@ static int damon_sysfs_set_attrs(struct damon_ctx *ctx,
 }
 
 static int damon_sysfs_set_regions(struct damon_target *t,
-               struct damon_sysfs_regions *sysfs_regions)
+               struct damon_sysfs_regions *sysfs_regions,
+               unsigned long min_sz_region)
 {
        struct damon_addr_range *ranges = kmalloc_array(sysfs_regions->nr,
                        sizeof(*ranges), GFP_KERNEL | __GFP_NOWARN);
@@ -1355,7 +1356,7 @@ static int damon_sysfs_set_regions(struct damon_target *t,
                if (ranges[i - 1].end > ranges[i].start)
                        goto out;
        }
-       err = damon_set_regions(t, ranges, sysfs_regions->nr);
+       err = damon_set_regions(t, ranges, sysfs_regions->nr, min_sz_region);
 out:
        kfree(ranges);
        return err;
@@ -1376,7 +1377,7 @@ static int damon_sysfs_add_target(struct damon_sysfs_target *sys_target,
                        /* caller will destroy targets */
                        return -EINVAL;
        }
-       return damon_sysfs_set_regions(t, sys_target->regions);
+       return damon_sysfs_set_regions(t, sys_target->regions, ctx->min_sz_region);
 }
 
 static int damon_sysfs_add_targets(struct damon_ctx *ctx,
@@ -1434,6 +1435,7 @@ static int damon_sysfs_apply_inputs(struct damon_ctx *ctx,
        if (err)
                return err;
        ctx->addr_unit = sys_ctx->addr_unit;
+       ctx->min_sz_region = max(DAMON_MIN_REGION / sys_ctx->addr_unit, 1);
        err = damon_sysfs_set_attrs(ctx, sys_ctx->attrs);
        if (err)
                return err;

diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h
index 5f5dc9db2e900987419c28b7167ce5839b124928..51369e35298b1cf7ce1eb5b3751d3e151aa1d291 100644 (file)
--- a/mm/damon/tests/core-kunit.h
+++ b/mm/damon/tests/core-kunit.h
@@ -230,14 +230,14 @@ static void damon_test_split_regions_of(struct kunit *test)
        t = damon_new_target();
        r = damon_new_region(0, 22);
        damon_add_region(r, t);
-       damon_split_regions_of(t, 2);
+       damon_split_regions_of(t, 2, DAMON_MIN_REGION);
        KUNIT_EXPECT_LE(test, damon_nr_regions(t), 2u);
        damon_free_target(t);
 
        t = damon_new_target();
        r = damon_new_region(0, 220);
        damon_add_region(r, t);
-       damon_split_regions_of(t, 4);
+       damon_split_regions_of(t, 4, DAMON_MIN_REGION);
        KUNIT_EXPECT_LE(test, damon_nr_regions(t), 4u);
        damon_free_target(t);
        damon_destroy_ctx(c);
@@ -303,7 +303,7 @@ static void damon_test_set_regions(struct kunit *test)
 
        damon_add_region(r1, t);
        damon_add_region(r2, t);
-       damon_set_regions(t, &range, 1);
+       damon_set_regions(t, &range, 1, DAMON_MIN_REGION);
 
        KUNIT_EXPECT_EQ(test, damon_nr_regions(t), 3);
        damon_for_each_region(r, t) {
@@ -450,25 +450,29 @@ static void damos_test_filter_out(struct kunit *test)
        damon_add_region(r, t);
 
        /* region in the range */
-       KUNIT_EXPECT_TRUE(test, damos_filter_match(NULL, t, r, f));
+       KUNIT_EXPECT_TRUE(test,
+                       damos_filter_match(NULL, t, r, f, DAMON_MIN_REGION));
        KUNIT_EXPECT_EQ(test, damon_nr_regions(t), 1);
 
        /* region before the range */
        r->ar.start = DAMON_MIN_REGION * 1;
        r->ar.end = DAMON_MIN_REGION * 2;
-       KUNIT_EXPECT_FALSE(test, damos_filter_match(NULL, t, r, f));
+       KUNIT_EXPECT_FALSE(test,
+                       damos_filter_match(NULL, t, r, f, DAMON_MIN_REGION));
        KUNIT_EXPECT_EQ(test, damon_nr_regions(t), 1);
 
        /* region after the range */
        r->ar.start = DAMON_MIN_REGION * 6;
        r->ar.end = DAMON_MIN_REGION * 8;
-       KUNIT_EXPECT_FALSE(test, damos_filter_match(NULL, t, r, f));
+       KUNIT_EXPECT_FALSE(test,
+                       damos_filter_match(NULL, t, r, f, DAMON_MIN_REGION));
        KUNIT_EXPECT_EQ(test, damon_nr_regions(t), 1);
 
        /* region started before the range */
        r->ar.start = DAMON_MIN_REGION * 1;
        r->ar.end = DAMON_MIN_REGION * 4;
-       KUNIT_EXPECT_FALSE(test, damos_filter_match(NULL, t, r, f));
+       KUNIT_EXPECT_FALSE(test,
+                       damos_filter_match(NULL, t, r, f, DAMON_MIN_REGION));
        /* filter should have split the region */
        KUNIT_EXPECT_EQ(test, r->ar.start, DAMON_MIN_REGION * 1);
        KUNIT_EXPECT_EQ(test, r->ar.end, DAMON_MIN_REGION * 2);
@@ -481,7 +485,8 @@ static void damos_test_filter_out(struct kunit *test)
        /* region started in the range */
        r->ar.start = DAMON_MIN_REGION * 2;
        r->ar.end = DAMON_MIN_REGION * 8;
-       KUNIT_EXPECT_TRUE(test, damos_filter_match(NULL, t, r, f));
+       KUNIT_EXPECT_TRUE(test,
+                       damos_filter_match(NULL, t, r, f, DAMON_MIN_REGION));
        /* filter should have split the region */
        KUNIT_EXPECT_EQ(test, r->ar.start, DAMON_MIN_REGION * 2);
        KUNIT_EXPECT_EQ(test, r->ar.end, DAMON_MIN_REGION * 6);

diff --git a/mm/damon/tests/vaddr-kunit.h b/mm/damon/tests/vaddr-kunit.h
index d2b37ccf2cc0651d28c25aa44096c9486eae6cc9..fce38dd53cf8f81ed94abcb1582df996e93f0fbd 100644 (file)
--- a/mm/damon/tests/vaddr-kunit.h
+++ b/mm/damon/tests/vaddr-kunit.h
@@ -141,7 +141,7 @@ static void damon_do_test_apply_three_regions(struct kunit *test,
                damon_add_region(r, t);
        }
 
-       damon_set_regions(t, three_regions, 3);
+       damon_set_regions(t, three_regions, 3, DAMON_MIN_REGION);
 
        for (i = 0; i < nr_expected / 2; i++) {
                r = __nth_region_of(t, i);

diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c
index 66ef9869eafe1100ead64aaaa8ac4195497cdeb7..8c048f9b129e6b76c70b3f0d11d4578502ca464b 100644 (file)
--- a/mm/damon/vaddr.c
+++ b/mm/damon/vaddr.c
@@ -299,7 +299,7 @@ static void damon_va_update(struct damon_ctx *ctx)
        damon_for_each_target(t, ctx) {
                if (damon_va_three_regions(t, three_regions))
                        continue;
-               damon_set_regions(t, three_regions, 3);
+               damon_set_regions(t, three_regions, 3, DAMON_MIN_REGION);
        }
 }