+ mm-damon-core-avoid-holes-in-newly-set-monitoring-target-ranges.patch added to mm-unstable branch

+ mm-damon-core-avoid-holes-in-newly-set-monitoring-target-ranges.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm/damon/core: avoid holes in newly set monitoring target ranges
has been added to the -mm mm-unstable branch.  Its filename is
     mm-damon-core-avoid-holes-in-newly-set-monitoring-target-ranges.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-avoid-holes-in-newly-set-monitoring-target-ranges.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@kernel.org>
Subject: mm/damon/core: avoid holes in newly set monitoring target ranges
Date: Fri, 9 Sep 2022 20:28:56 +0000

When there are two or more non-contiguous regions intersecting with given
new ranges, 'damon_set_regions()' does not fill the holes.  This commit
makes the function to fill the holes with newly created regions.

Link: https://lkml.kernel.org/r/20220909202901.57977-3-sj@kernel.org
Fixes: 3f49584b262c ("mm/damon: implement primitives for the virtual memory address spaces")
Signed-off-by: SeongJae Park <sj@kernel.org>
Reported-by: Yun Levi <ppbuk5246@gmail.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/damon/core.c |   24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

--- a/mm/damon/core.c~mm-damon-core-avoid-holes-in-newly-set-monitoring-target-ranges
+++ a/mm/damon/core.c
@@ -169,6 +169,27 @@ static bool damon_intersect(struct damon
 }
 
 /*
+ * Fill holes in regions with new regions.
+ */
+static void damon_fill_regions_holes(struct damon_region *first,
+		struct damon_region *last, struct damon_target *t)
+{
+	struct damon_region *r = first;
+
+	damon_for_each_region_from(r, t) {
+		struct damon_region *next, *newr;
+
+		if (r == last)
+			break;
+		next = damon_next_region(r);
+		if (r->ar.end != next->ar.start) {
+			newr = damon_new_region(r->ar.end, next->ar.start);
+			damon_insert_region(newr, r, next, t);
+		}
+	}
+}
+
+/*
  * damon_set_regions() - Set regions of a target for given address ranges.
  * @t:		the given target.
  * @ranges:	array of new monitoring target ranges.
@@ -226,6 +247,9 @@ int damon_set_regions(struct damon_targe
 			first->ar.start = ALIGN_DOWN(range->start,
 					DAMON_MIN_REGION);
 			last->ar.end = ALIGN(range->end, DAMON_MIN_REGION);
+
+			/* fill possible holes in the range */
+			damon_fill_regions_holes(first, last, t);
 		}
 	}
 	return 0;
_

Patches currently in -mm which might be from sj@kernel.org are

mm-demotion-update-node_is_toptier-to-work-with-memory-tiers-fix.patch
selftest-damon-add-a-test-for-duplicate-context-dirs-creation.patch
mm-damon-core-avoid-holes-in-newly-set-monitoring-target-ranges.patch
mm-damon-core-test-test-damon_set_regions.patch
docs-admin-guide-mm-damon-rename-the-title-of-the-document.patch
mm-damon-kconfig-notify-debugfs-deprecation-plan.patch
docs-admin-guide-mm-damon-start-mention-the-dependency-as-sysfs-instead-of-debugfs.patch
docs-admin-guide-mm-damon-usage-note-damon-debugfs-interface-deprecation-plan.patch