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 4274B3DB980; Tue, 30 Jun 2026 04:08:30 +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=1782792511; cv=none; b=cwhV6ScUKU6xnYv/iLKlbM/dFVEgEdsoS87w2g9es+CfA3TrIPcapZw833I7SLw3iU+6eOY3uEJDsK86eu4x6uOtUBqKFmBqlPy1d/Wk/HaJQb1oO8LGH0IWZ+aYoWdYMHx/SEnkV4FGUYdiXty4KvoPp3rrR0kJIP6YN0iNUSQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782792511; c=relaxed/simple; bh=jS4uL8HqEfFXspqlq5sLj/7oRX78/zw9vA1W3pExdXk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LHFRMSkMhS1wguONBR0STNAHYWOyWL2i9mUoRGexONezFqshvfflnfx0Pt0gzbZE/V/OY7R+7uEFJ5R+vPy9RLWiXg67wfDWYaXjJy2zshpAV9EiUcnsF3+rIPfxbkaINdbpPXLt7p4KZFsNh64vGtCClb7mEVjFQj9/iT+JmAg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fw63Lx7a; 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="fw63Lx7a" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 04C501F00A3D; Tue, 30 Jun 2026 04:08:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782792510; bh=ISgM0/IpFYdSGK1NuzNK8sv6iik/7pwEzAP44Tm5nXw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=fw63Lx7akv48hSwtD/WuDicFwfkoCl91ylnECKFw+TiGqiD2mHcHh1ipb9VvgwOKa YVDD+BBHiDHLSmMnR1fbrtrytq80tHi77Ze0VYxdazJTMDP12U69JuGAt9v65jsYAB X/WC3KZjelGUvsw3vq8UZxe7rdOlI361ClhdrtxTou7BwZaepJkjC9rX3dvDB7ULl+ rIW4O/LQnQnq0U5wIkVJEtQ5TiHzRMBKphLXCfcp/GVBpPoMvhu0jS/uA74dHb1EcF G6/KJbKegj4/IgojjMdm4SvUvMwFzTfihg9cdvtxki0rye5UweV5XXiT58JfoAu2UE DPENrFlPK0OgQ== From: SJ Park To: Andrew Morton Cc: SJ Park , damon@lists.linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 13/18] mm/damon/core: remove nr_accesses_bp setups and updates Date: Mon, 29 Jun 2026 21:08:06 -0700 Message-ID: <20260630040812.149729-14-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260630040812.149729-1-sj@kernel.org> References: <20260630040812.149729-1-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: SJ 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 78c32ee45d28b..dcd5e484fa442 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -302,7 +302,6 @@ 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); @@ -882,20 +881,17 @@ 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); } @@ -3110,7 +3106,6 @@ 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 */ @@ -3222,7 +3217,6 @@ 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)); @@ -3830,18 +3824,6 @@ 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