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However, damos_set_effective_quota() clamps the esz to min_region_sz when quota->ms is set. This is a minor issue, the main problem is that it doesn't match the description in the documentation, which state that if the goal has already been [over-]achieved, the quota will be set to zero. Fix this by set quota (esz) as minimum as possible. Fixes: 8bbde987c2b8 ("mm/damon/core: disallow time-quota setting zero esz") Cc: # v7.1.x Signed-off-by: Liew Rui Yan --- Changes from v2: - v2: https://lore.kernel.org/damon/20260902082050.19566-1-aethernet65535@gmail.com - Changed implementation, more general implementation provided by SJ. [1] [1] https://lore.kernel.org/damon/20260902150301.88535-1-sj@kernel.org Changes from v1: - v1: https://lore.kernel.org/damon/20260901105951.106246-1-aethernet65535@gmail.com - Changed implementation. The initial solution skipped the min_region_sz clamping when esz was already zero. However, this would revert the fix from commit 8bbde987c2b8 and cause a regression. This revision fixes the issue by adding a specific check for a zero esz_bp. - Changed patch title, original title: fix quota could not be set to zero --- mm/damon/core.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/mm/damon/core.c b/mm/damon/core.c index 644daf5a1656..2b294fb46648 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -3091,6 +3091,7 @@ static void damos_set_effective_quota(struct damon_ctx *ctx, struct damos *s) struct damos_quota *quota = &s->quota; unsigned long throughput; unsigned long esz = ULONG_MAX; + unsigned long esz_time; if (!quota->ms && list_empty("a->goals)) { quota->esz = quota->sz; @@ -3111,8 +3112,8 @@ static void damos_set_effective_quota(struct damon_ctx *ctx, struct damos *s) 1000000, quota->total_charged_ns); else throughput = PAGE_SIZE * 1024; - esz = min(throughput * quota->ms, esz); - esz = max(ctx->min_region_sz, esz); + esz_time = max(throughput * quota->ms, ctx->min_region_sz); + esz = min(esz_time, esz); } if (quota->sz && quota->sz < esz) -- 2.55.0