The patch titled Subject: mm/damon/core: copy nr_accesses when splitting region has been added to the -mm mm-hotfixes-unstable branch. Its filename is mm-damon-core-copy-nr_accesses-when-splitting-region.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-copy-nr_accesses-when-splitting-region.patch This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: SeongJae Park <sj@xxxxxxxxxx> Subject: mm/damon/core: copy nr_accesses when splitting region Date: Sun, 19 Nov 2023 17:15:28 +0000 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@xxxxxxxxxx Fixes: 42f994b71404 ("mm/damon/core: implement scheme-specific apply interval") Signed-off-by: SeongJae Park <sj@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/damon/core.c | 1 + 1 file changed, 1 insertion(+) --- a/mm/damon/core.c~mm-damon-core-copy-nr_accesses-when-splitting-region +++ a/mm/damon/core.c @@ -1225,6 +1225,7 @@ 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; + new->nr_accesses = r->nr_accesses; damon_insert_region(new, r, damon_next_region(r), t); } _ Patches currently in -mm which might be from sj@xxxxxxxxxx are mm-damon-core-copy-nr_accesses-when-splitting-region.patch