6.6-stable review patch. If anyone has any objections, please let me know.
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From: SeongJae Park sj@kernel.org
commit 1f3730fd9e8d4d77fb99c60d0e6ad4b1104e7e04 upstream.
Regions split function ('damon_split_region_at()') is called at the beginning of an aggregation interval, and when DAMOS applying the actions and charging quota. Because 'nr_accesses' fields of all regions are reset at the beginning of each aggregation interval, and DAMOS was applying the action at the end of each aggregation interval, there was no need to copy the 'nr_accesses' field to the split-out region.
However, commit 42f994b71404 ("mm/damon/core: implement scheme-specific apply interval") made DAMOS applies action on its own timing interval. Hence, 'nr_accesses' should also copied to split-out regions, but the commit didn't. Fix it by copying it.
Link: https://lkml.kernel.org/r/20231119171529.66863-1-sj@kernel.org Fixes: 42f994b71404 ("mm/damon/core: implement scheme-specific apply interval") Signed-off-by: SeongJae Park sj@kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- mm/damon/core.c | 1 + 1 file changed, 1 insertion(+)
--- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -1215,6 +1215,7 @@ static void damon_split_region_at(struct
new->age = r->age; new->last_nr_accesses = r->last_nr_accesses; + new->nr_accesses = r->nr_accesses;
damon_insert_region(new, r, damon_next_region(r), t); }