+ mm-damon-core-set-effective-quota-on-first-charge-window.patch added to mm-new branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm/damon/core: set effective quota on first charge window
has been added to the -mm mm-new branch.  Its filename is
     mm-damon-core-set-effective-quota-on-first-charge-window.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-set-effective-quota-on-first-charge-window.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
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------------------------------------------------------
From: SeongJae Park <sj@kernel.org>
Subject: mm/damon/core: set effective quota on first charge window
Date: Sun, 14 Sep 2025 18:58:03 -0700

The effective quota of a scheme is initialized zero, which means there is
no quota.  It is set based on user-specified time/quota/quota goals.  But
the later value set is done only from the second charge window.  As a
result, a scheme having a user-specified quota can work as not having the
quota (unexpectedly fast) for the first charge window.  In practical and
common use cases the quota interval is not too long, and the scheme's
target access pattern is restrictive.  Hence the issue should be modest. 
That said, it is apparently an unintended misbehavior.  Fix the problem by
setting esz on the first charge window.

Link: https://lkml.kernel.org/r/20250915015807.101505-3-sj@kernel.org
Fixes: 1cd243030059 ("mm/damon/schemes: implement time quota") # 5.16.x
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/damon/core.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/mm/damon/core.c~mm-damon-core-set-effective-quota-on-first-charge-window
+++ a/mm/damon/core.c
@@ -2142,8 +2142,10 @@ static void damos_adjust_quota(struct da
 		return;
 
 	/* First charge window */
-	if (!quota->total_charged_sz && !quota->charged_from)
+	if (!quota->total_charged_sz && !quota->charged_from) {
 		quota->charged_from = jiffies;
+		damos_set_effective_quota(quota);
+	}
 
 	/* New charge window starts */
 	if (time_after_eq(jiffies, quota->charged_from +
_

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

mm-damon-core-reset-age-if-nr_accesses-changes-between-non-zero-and-zero.patch
mm-damon-core-set-effective-quota-on-first-charge-window.patch
mm-damon-lru_sort-use-param_ctx-correctly.patch
docs-mm-damon-maintainer-profile-update-community-meetup-for-reservation-requirements.patch
docs-admin-guide-mm-damon-start-add-target_pid-to-damos-example-command.patch
maintainers-rename-damon-section.patch