Commit 9c950c22 authored by SeongJae Park's avatar SeongJae Park Committed by Andrew Morton
Browse files

mm/damon/core: avoid holes in newly set monitoring target ranges 

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.

[sj@kernel.org: handle error from 'damon_fill_regions_holes()']
  Link: https://lkml.kernel.org/r/20220913215420.57761-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20220909202901.57977-3-sj@kernel.org


Fixes: 3f49584b ("mm/damon: implement primitives for the virtual memory address spaces")
Signed-off-by: default avatarSeongJae Park <sj@kernel.org>
Reported-by: default avatarYun 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: default avatarAndrew Morton <akpm@linux-foundation.org>
parent ade38b8c

mm/damon/core.c

+30 −0
Original line number Diff line number Diff line
@@ -168,6 +168,30 @@ static bool damon_intersect(struct damon_region *r, 
	return !(r->ar.end <= re->start || re->end <= r->ar.start);

}



/*

 * Fill holes in regions with new regions.

 */

static int 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);

			if (!newr)

				return -ENOMEM;

			damon_insert_region(newr, r, next, t);

		}

	}

	return 0;

}



/*

 * damon_set_regions() - Set regions of a target for given address ranges.

 * @t:		the given target.
@@ -184,6 +208,7 @@ int damon_set_regions(struct damon_target *t, struct damon_addr_range *ranges, 
{

	struct damon_region *r, *next;

	unsigned int i;

	int err;



	/* Remove regions which are not in the new ranges */

	damon_for_each_region_safe(r, next, t) {
@@ -226,6 +251,11 @@ int damon_set_regions(struct damon_target *t, struct damon_addr_range *ranges, 
			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 */

			err = damon_fill_regions_holes(first, last, t);

			if (err)

				return err;

		}

	}

	return 0;