The patch titled
Subject: mm/damon/core: introduce nr_accesses_bp
has been added to the -mm mm-unstable branch. Its filename is
mm-damon-core-introduce-nr_accesses_bp.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-damon-core-introduce-nr_accesses_bp.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: SeongJae Park <sj@xxxxxxxxxx>
Subject: mm/damon/core: introduce nr_accesses_bp
Date: Fri, 15 Sep 2023 02:52:48 +0000
Add yet another representation of the access rate of each region, namely
nr_accesses_bp. It is just same to the nr_accesses but represents the
value in basis point (1 in 10,000), and updated at once in every
aggregation interval. That is, moving_accesses_bp is just nr_accesses *
10000. This may seems useless at the moment. However, it will be useful
for representing less than one nr_accesses value that will be needed to
make moving sum-based nr_accesses.
Link: https://lkml.kernel.org/r/20230915025251.72816-6-sj@xxxxxxxxxx
Signed-off-by: SeongJae Park <sj@xxxxxxxxxx>
Cc: Brendan Higgins <brendanhiggins@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/damon.h | 5 +++++
mm/damon/core-test.h | 5 +++++
mm/damon/core.c | 6 ++++++
3 files changed, 16 insertions(+)
--- a/include/linux/damon.h~mm-damon-core-introduce-nr_accesses_bp
+++ a/include/linux/damon.h
@@ -40,6 +40,7 @@ struct damon_addr_range {
* @ar: The address range of the region.
* @sampling_addr: Address of the sample for the next access check.
* @nr_accesses: Access frequency of this region.
+ * @nr_accesses_bp: @nr_accesses in basis point (0.01%).
* @list: List head for siblings.
* @age: Age of this region.
*
@@ -49,6 +50,9 @@ struct damon_addr_range {
* not be done with direct access but with the helper function,
* damon_update_region_access_rate().
*
+ * @nr_accesses_bp is another representation of @nr_accesses in basis point
+ * (1 in 10,000) that updated every aggregation interval.
+ *
* @age is initially zero, increased for each aggregation interval, and reset
* to zero again if the access frequency is significantly changed. If two
* regions are merged into a new region, both @nr_accesses and @age of the new
@@ -58,6 +62,7 @@ struct damon_region {
struct damon_addr_range ar;
unsigned long sampling_addr;
unsigned int nr_accesses;
+ unsigned int nr_accesses_bp;
struct list_head list;
unsigned int age;
--- a/mm/damon/core.c~mm-damon-core-introduce-nr_accesses_bp
+++ a/mm/damon/core.c
@@ -128,6 +128,7 @@ struct damon_region *damon_new_region(un
region->ar.start = start;
region->ar.end = end;
region->nr_accesses = 0;
+ region->nr_accesses_bp = 0;
INIT_LIST_HEAD(®ion->list);
region->age = 0;
@@ -508,6 +509,7 @@ static void damon_update_monitoring_resu
{
r->nr_accesses = damon_nr_accesses_for_new_attrs(r->nr_accesses,
old_attrs, new_attrs);
+ r->nr_accesses_bp = r->nr_accesses * 10000;
r->age = damon_age_for_new_attrs(r->age, old_attrs, new_attrs);
}
@@ -1115,6 +1117,7 @@ static void damon_merge_two_regions(stru
l->nr_accesses = (l->nr_accesses * sz_l + r->nr_accesses * sz_r) /
(sz_l + sz_r);
+ l->nr_accesses_bp = l->nr_accesses * 10000;
l->age = (l->age * sz_l + r->age * sz_r) / (sz_l + sz_r);
l->ar.end = r->ar.end;
damon_destroy_region(r, t);
@@ -1138,6 +1141,8 @@ static void damon_merge_regions_of(struc
else
r->age++;
+ r->nr_accesses_bp = r->nr_accesses * 10000;
+
if (prev && prev->ar.end == r->ar.start &&
abs(prev->nr_accesses - r->nr_accesses) <= thres &&
damon_sz_region(prev) + damon_sz_region(r) <= sz_limit)
@@ -1186,6 +1191,7 @@ static void damon_split_region_at(struct
new->age = r->age;
new->last_nr_accesses = r->last_nr_accesses;
+ new->nr_accesses_bp = r->nr_accesses_bp;
damon_insert_region(new, r, damon_next_region(r), t);
}
--- a/mm/damon/core-test.h~mm-damon-core-introduce-nr_accesses_bp
+++ a/mm/damon/core-test.h
@@ -94,6 +94,7 @@ static void damon_test_aggregate(struct
for (ir = 0; ir < 3; ir++) {
r = damon_new_region(saddr[it][ir], eaddr[it][ir]);
r->nr_accesses = accesses[it][ir];
+ r->nr_accesses_bp = accesses[it][ir] * 10000;
damon_add_region(r, t);
}
it++;
@@ -147,9 +148,11 @@ static void damon_test_merge_two(struct
t = damon_new_target();
r = damon_new_region(0, 100);
r->nr_accesses = 10;
+ r->nr_accesses_bp = 100000;
damon_add_region(r, t);
r2 = damon_new_region(100, 300);
r2->nr_accesses = 20;
+ r2->nr_accesses_bp = 200000;
damon_add_region(r2, t);
damon_merge_two_regions(t, r, r2);
@@ -196,6 +199,7 @@ static void damon_test_merge_regions_of(
for (i = 0; i < ARRAY_SIZE(sa); i++) {
r = damon_new_region(sa[i], ea[i]);
r->nr_accesses = nrs[i];
+ r->nr_accesses_bp = nrs[i] * 10000;
damon_add_region(r, t);
}
@@ -297,6 +301,7 @@ static void damon_test_update_monitoring
struct damon_region *r = damon_new_region(3, 7);
r->nr_accesses = 15;
+ r->nr_accesses_bp = 150000;
r->age = 20;
new_attrs = (struct damon_attrs){
_
Patches currently in -mm which might be from sj@xxxxxxxxxx are
docs-admin-guide-mm-damon-usage-fixup-missed-ref-keyword.patch
docs-admin-guide-mm-damon-usage-place-debugfs-usage-at-the-bottom.patch
docs-admin-guide-mm-damon-usage-move-debugfs-intro-to-the-bottom-of-the-section.patch
docs-mm-damon-design-explicitly-introduce-nr_accesses.patch
docs-admin-guide-mm-damon-usage-explain-the-format-of-damon_aggregate-tracepoint.patch
docs-mm-damon-design-add-a-section-for-kdamond-and-damon-context.patch
docs-admin-guide-mm-damon-usage-link-design-doc-for-details-of-kdamond-and-context.patch
mm-damon-core-fix-a-comment-about-damon_set_attrs-call-timings.patch
mm-damon-core-add-more-comments-for-nr_accesses.patch
mm-damon-core-remove-duplicated-comment-for-watermarks-based-deactivation.patch
mm-damon-core-remove-struct-target-parameter-from-damon_aggregated-tracepoint.patch
mm-damon-core-add-a-tracepoint-for-damos-apply-target-regions.patch
docs-admin-guide-mm-damon-usage-document-damos_before_apply-tracepoint.patch
mm-damon-core-use-number-of-passed-access-sampling-as-a-timer.patch
mm-damon-core-define-and-use-a-dedicated-function-for-region-access-rate-update.patch
mm-damon-vaddr-call-damon_update_region_access_rate-always.patch
mm-damon-core-implement-a-pseudo-moving-sum-function.patch
mm-damon-core-test-add-a-unit-test-for-damon_moving_sum.patch
mm-damon-core-introduce-nr_accesses_bp.patch
mm-damon-core-use-pseudo-moving-sum-for-nr_accesses_bp.patch
mm-damon-core-skip-updating-nr_accesses_bp-for-each-aggregation-interval.patch
mm-damon-core-mark-damon_moving_sum-as-a-static-function.patch
