From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AB48F3BE636; Mon, 22 Jun 2026 14:22:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782138125; cv=none; b=bE1znWfNxG76PeoyZkgnW9jLkUszIiJyuZ58B0vPirVJ8UOaU3rzQx4fv56mtTOUK0lUX1ekQdH7u/JTmL1bvyAqjvF2Vg2eetfjAafpC5gS21DbactQHAD2+mgcQJDI6L6jexn3I9Xu+g5k5+wZUnRQCKcqGXemi5lM+Pwv3OA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782138125; c=relaxed/simple; bh=3k5/sgMyEFl7Pm61/oDYcT/SsoNqJArhNImPs3atqMs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=iqi4RcqYyIw7jaeS2Qfbmx/qBGyz7tIdVQy3neopemCc5zdeOAMd//PKmf6Lg+9svwbyCHmP9KWu9THiujKohNWg/Fel3BFMceFgHhFtFq6kSz5PZBzoIR2vg6t2tdh9PW1M+QJrWl4rDoFMihAYXmkGYYDBEtSbiL3TfzS9kPo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gLzrbKBC; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="gLzrbKBC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D48CD1F00A3A; Mon, 22 Jun 2026 14:22:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782138124; bh=ZFWaG18Q1S2T37NGDzr0/yr5IxRaKdmsNfBt6SXMm64=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=gLzrbKBCZEQt7wyxBpv4Q96/r5dgTtOv9wq4fhy50NxZwjlFY92gv75SeROaBvwXj inPw7ndaGjFDP22G+mLlJ0gbKpEtgl3XrdGESAiJhBpO6XcJtILubsitaeEaxL6wLI mfpKglUHuGT/vlemS+kWO4IEC2qjNTAf9YOgjMnncul58DV9fmif1UWsKJEL7GI4bk 1DC06Rmj/ugzl9fRfNj75DaH6EQ4R05I/dhrw8QFVZKLmM6sVMo4uLVJccxDrRW0PQ CYb+n19md7+9nx743LuLzujioJetuxLp1FFfO7SsyzmtNpR9uESs1ZyXeSxcZSMnta wN7pFr5j35gsw== From: SeongJae Park To: Cc: SeongJae Park , Andrew Morton , damon@lists.linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [RFC PATCH v1.3 13/18] mm/damon/core: remove nr_accesses_bp setups and updates Date: Mon, 22 Jun 2026 07:21:33 -0700 Message-ID: <20260622142139.30269-14-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260622142139.30269-1-sj@kernel.org> References: <20260622142139.30269-1-sj@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit DAMON core sets and updates nr_accesses_bp in multiple places. It explains how delicate it is. The field is no more being used for any real purpose, and replaced by a simpler function. Remove the setups and updates. Signed-off-by: SeongJae Park --- mm/damon/core.c | 22 ++-------------------- 1 file changed, 2 insertions(+), 20 deletions(-) diff --git a/mm/damon/core.c b/mm/damon/core.c index 80c1b34062312..b095f053c6fa6 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -304,7 +304,6 @@ struct damon_region *damon_new_region(unsigned long start, unsigned long end) region->ar.start = start; region->ar.end = end; region->nr_accesses = 0; - region->nr_accesses_bp = 0; for (i = 0; i < DAMON_MAX_PROBES; i++) region->probe_hits[i] = 0; INIT_LIST_HEAD(®ion->list); @@ -878,20 +877,17 @@ static void damon_update_monitoring_result(struct damon_region *r, { r->last_nr_accesses = damon_nr_accesses_for_new_attrs( r->last_nr_accesses, old_attrs, new_attrs); - if (!aggregating) { + if (!aggregating) r->nr_accesses = damon_nr_accesses_for_new_attrs( r->nr_accesses, old_attrs, new_attrs); - r->nr_accesses_bp = r->nr_accesses * 10000; - } else { + else /* * if this is called in the middle of the aggregation, reset * the aggregations we made so far for this aggregation * interval. In other words, make the status like * kdamond_reset_aggregated() is called. */ - r->nr_accesses_bp = r->last_nr_accesses * 10000; r->nr_accesses = 0; - } r->age = damon_age_for_new_attrs(r->age, old_attrs, new_attrs); } @@ -3106,7 +3102,6 @@ static void damon_merge_two_regions(struct damon_target *t, l->nr_accesses = (l->nr_accesses * sz_l + r->nr_accesses * sz_r) / (sz_l + sz_r); - l->nr_accesses_bp = l->nr_accesses * 10000; l->age = (l->age * sz_l + r->age * sz_r) / (sz_l + sz_r); l->ar.end = r->ar.end; /* todo: do this for only installed probes */ @@ -3218,7 +3213,6 @@ static void damon_split_region_at(struct damon_target *t, 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; /* todo: do this for only installed probes */ memcpy(new->probe_hits, r->probe_hits, sizeof(r->probe_hits)); @@ -3787,18 +3781,6 @@ static unsigned int damon_moving_sum(unsigned int mvsum, unsigned int nomvsum, void damon_update_region_access_rate(struct damon_region *r, bool accessed, struct damon_attrs *attrs) { - unsigned int len_window = 1; - - /* - * sample_interval can be zero, but cannot be larger than - * aggr_interval, owing to validation of damon_set_attrs(). - */ - if (attrs->sample_interval) - len_window = damon_max_nr_accesses(attrs); - r->nr_accesses_bp = damon_moving_sum(r->nr_accesses_bp, - r->last_nr_accesses * 10000, len_window, - accessed ? 10000 : 0); - if (accessed) r->nr_accesses++; } -- 2.47.3