From 9c950c22833cfd9887da7679534e5c6deb44b008 Mon Sep 17 00:00:00 2001 From: SeongJae Park Date: Fri, 9 Sep 2022 20:28:56 +0000 Subject: 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: 3f49584b262c ("mm/damon: implement primitives for the virtual memory address spaces") Signed-off-by: SeongJae Park Reported-by: Yun Levi Cc: Brendan Higgins Cc: Jonathan Corbet Cc: Shuah Khan Signed-off-by: Andrew Morton --- mm/damon/core.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 'mm/damon/core.c') diff --git a/mm/damon/core.c b/mm/damon/core.c index bae41990f422..5ad31d2feae4 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -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; -- cgit v1.2.3